PMC Paid Practice Tests Series 2021 With Explanation - Test 33

Shahid · July 3

Prepare the PMC Paid Practice Tests Series 2021 with our comprehensive past paper and explanation guide. Gain valuable insights into the exam format, question types, and essential topics covered. Our detailed explanations will help you understand the reasoning behind each answer, allowing you to strengthen your knowledge and improve your performance. Get a head start on your exam preparation and increase your chances of success with our PMC Paid Practice Tests Series 2021 past paper and explanation resource.

QUESTION: The Earth ______ (move) around the sun.
A. Move
B. Moving
C. Moves
D. Had moved
EXPLANATION
As “Earth” is a third person singular word, “-s” or “-es” must be added to the verb that follows it.

QUESTION: You must had (A)/ a kind and gentle heart (B) if you want (C) / to become a successful doctor (D)
A. You must had
B. A kind and gentle heart.
C. If you want.
D. To become a successful doctor.
EXPLANATION
The given sentence is in the future tense, as indicated by “if you want to”. The only statement that does not follow the tense is statement A due to having “had” (past tense).

QUESTION: Choose the correct sentence:
A. The weather in August is usually very humid!
EXPLANATION
Option B displays the correct use of capitalization to refer to proper nouns and the correct use of punctuation to indicate a declarative sentence.

QUESTION: Michael ___ absent yesterday.
A. Is
B. Was
C. Were
D. Being
EXPLANATION
The word “yesterday” indicates past tense. Hence, the past tense form of the verb will be used.

QUESTION: Reluctant
A. Hesitant
B. Ready
C. Eager
D. Willing
EXPLANATION
This question tests vocabulary. The definitions of “reluctant” and “hesitant” both involve being unwilling or unsure.

QUESTION: According to the information on this page, items bought before 1940 _____ more than items made after that year.
A. Costs
B. Costed
C. Costing
D. Cost
EXPLANATION
The subject in the given sentence is the plural noun ‘items’, hence the plural form of the main verb will be used.

QUESTION: Relinquish
A. Use
B. Surrender
C. Increase
D. Retain
EXPLANATION
This question tests vocabulary. The definitions of “relinquish” and “surrender” both involve voluntarily giving something up.

QUESTION: What is the tense of this question? What are the shops like around here?
A. Present
B. Past
C. Future
D. None of these
EXPLANATION
The given statement is in present tense. (due to the word “are”)

QUESTION: You will find more information in the ___ .
A. Attached to file
B. Attached file
C. Attachment file
D. File what is attached
EXPLANATION
An adjective before a noun cannot have any information after it i.e between it and the noun. Hence, the correct option is B.

QUESTION: Choose the correct spelling of the word:
A. Developement
B. Devalopment
C. Davalopment
D. Development
EXPLANATION
This question tests vocabulary. The correct spelling is option D, “development”.

QUESTION: Can you pass me ______ salt?
A. A
B. An
C. The
D. No article
EXPLANATION
The salt being referred to is a specific noun (known by the speaker and the listener). Hence, “the” will be used to refer to it.

QUESTION: Some of the people waiting in line ___ getting impatient.
A. Is
B. Was
C. Are
D. Be
EXPLANATION
The “people in the line” is plural, hence the plural form of the verb will be used.

QUESTION: Which tense would you use for talking about the area where you live?
A. Present
B. Past
C. Future
D. None of these
EXPLANATION
The given question indicates present tense through the word “live”. Hence, present tense will be used.

QUESTION: Choose the correct spelling of the word:
A. Excellant
B. Excalant
C. Excelent
D. Excellent
EXPLANATION
This question tests vocabulary. The correct spelling is Option D, “excellent”.

QUESTION: Choose the correct sentence:
A. I like to cook I like to make cake, bread and pie.
B. I like to cook. I like to make cake, bread and pie!
C. I like to cook; I like to make cake, bread and pie.
EXPLANATION
Option D displays the correct use of punctuation to separate clauses and indicate declarative sentences.

QUESTION: When she parted ______ her parents, her eyes were full of tears.
A. From
B. Away
C. Off
D. With
EXPLANATION
This question tests vocabulary. To part with something means to give it up or to be separated from it.

QUESTION: Find the error?
A. It has not rained since April.
B. The jurors walked solemnly into the room.
C. Had we known, we would not have come.
D. No mistakes
EXPLANATION
All three given sentences are correct.

QUESTION: Choose the correct sentence:
A. Beware of the upcoming storm, the weather forecaster warned on national television.
EXPLANATION
Option B displays correct use of punctuation to indicate spoken dialogue and declarative sentences, and correct use of capitalization.

QUESTION: There is ________ institution for________ blind in this city.
A. A ... an
B. A ... the
C. An .. a
D. An .. the
EXPLANATION
“Institution” starts with a consonant sound hence it will be conjugated with “an”. The “blind” is a specific group of people, hence “the” will be used to refer to them.

QUESTION: Not only the students but also their instructor ____ been called to the principals office.
A. Has
B. Have
C. Were
D. Was
EXPLANATION
The subject of the given sentence is the instructor (singular), hence the singular form of the verb will be used.

QUESTION: Who opposed the idea the cell is an empty space bounded by thick wall?
A. Lorenz oken
B. Schwann
C. Robert brown
D. Rudolph Virchow
EXPLANATION
Option C is correct because: In 1831 Robert Brown reported the presence of a nucleus in the cell. Due to this discovery Robert Hooke’s idea about the cell as an empty space was changed. It was later established that cell is not an empty space. Options A,B and D are incorrect because: These scientists did not oppose the idea.

QUESTION: What are the subunits of capsids?
A. Capsomeres
B. Flagella
C. Hyphae
D. Septa
EXPLANATION
Option A is correct because: Capsid is a protein shell found in viruses enclosing its genetic material and its subunits are known as capsomeres Option B is incorrect because: Flagella is a tail like appendage used for locomotion and is not present in viruses Option C is incorrect because: Hyphae are long branching filamentous structures used for vegetative growth and are not found in viruses Option D is incorrect because: Septa are partitions dividing two chambers such as the two chambers of the heart

QUESTION: Nicotinamide adenine dinucleotide is an example of:
A. Coenzyme
B. Holoenzyme
C. Cofactor
D. Apoenzyme
EXPLANATION
Option A is correct because: NAD belongs to a class of enzymes known as coenzymes and assists in the process of respiration acting as an electron carrier. Coenzymes are organic molecules. Other examples of coenzymes are FAD and Coenzyme A (CoA). Option B is incorrect because: Holoenzyme simply refers to the active form of an enzyme attached to its respective co factor and is not used for the classification of enzymes. Option C is incorrect because: Cofactor is the non protein part of an enzyme which is required for the normal functioning of an enzyme. Option D is incorrect because: Apoenzyme refers to an inactive enzyme without its cofactor or prosthetic group attached.

QUESTION: Adaptation of traits to better fill a niche is known as which of the following?
A. Polymorphism
B. Gene linkage
C. Specialization
D. Replication
EXPLANATION
Option C is correct because: Specialization refers to organisms adapting their traits to be able to better play a specific role in the environment. Option A is incorrect because: Polymorphism refers to a specific genetic trait being expressed as more than one phenotype. Option B is incorrect because: Gene linkage refers to genes close together on a chromosome being inherited together. Option D is incorrect because: Replication is a process by which cells or organisms divide.

QUESTION: Organisms that have one copy of each gene on each chromosome are?
A. Diploid
B. Haploid
C. Unicellular
D. None of these
EXPLANATION
Option A is correct because: Diploid refers to an organism having 2n number of chromosomes with chromosomes coming from both parents equally hence a copy of a gene comes from both parents. As a result there is a copy of a specific gene on both chromosomes of a set of chromosomes. Option B is incorrect because: In haploid all the chromosomes only come from one parent so the organism or cell only receives one copy of the gene. Option C is incorrect because: Unicellular means one cell like unicellular organisms and has nothing to do with genetics. Option D is incorrect because: Option A is correct.

QUESTION: Cellular respiration is essentially what type of process?
A. Oxidation
B. Reduction
C. Redox
D. None of the above options is correct.
EXPLANATION
Option C is correct because: In respiration, oxygen gets reduced and glucose gets oxidized by the cells to generate energy in the form of ATP and release carbon dioxide and water. Since glucose is being oxidized and oxygen being reduced the reaction is a redox reaction. C₆H₁₂O₆+ 6O₂→ 6CO₂+ 6H₂O + energy Option A and B are incorrect because ONLY oxidation or reduction CAN NOT take place in a reaction, because if one atom losses an electron (oxidises) another atom will accept it (reduced), causing both oxidation and reduction in the same reaction. Option D cannot be the correct answer.

QUESTION: The animals in which coelom is formed due to splitting of mesoderm are known as which of the following?
A. Pseudocoelom
B. Enterocoelous
C. Amphicoelous
D. Schizocoelous
EXPLANATION
Option D is correct because:

QUESTION: The branch of biology which deals with the study of chemical compounds and the chemical processes in the living organisms is called?
A. Chemistry
B. Biochemistry
C. Molecular biology
D. Both a and b
EXPLANATION
Option B is correct because: In biochemistry bio refers to study of living things and chemistry refers to study of chemical compounds and chemical processes. So these compounds and chemical processes being studied in living things is called biochemistry. Option A is incorrect because: Chemistry refers to the study of chemical compounds and chemical reactions in general not only in living things. Option C is incorrect because: Molecular biology is the study of macromolecules such as proteins essential for life. Option D is incorrect because: Option B is correct.

QUESTION: The path taken by the nerve impulses in a reflex is called a:
A. Nerve cell
B. Reflex arc
C. Receptor cells
D. Mixed nerve
EXPLANATION
Option B is correct because: During reflex action nerve impulses take a special route through the spinal cord bypassing the brain for an immediate effect and this path is called reflex arc. Option A is incorrect because: Nerve cell is a cell and not a path taken. Option C is incorrect because: Receptor cells are cells and not a path taken. Option D is incorrect because: Mixed nerve refers to a mixture of sensory and motor neurons and is not a path taken.

QUESTION: Proteins and lipids are converted into glycolipids and glycoproteins by adding carbohydrates by?
A. Ribosomes
B. Cytoplasm
C. Golgi apparatus
D. Endoplasmic reticulum
EXPLANATION
Option C is correct because: The role of the golgi apparatus is to modify and package proteins which it achieves by adding lipids or carbohydrates to proteins forming glycolipids and glycoproteins which are then packaged into golgi vesicles. Option A is incorrect because: The role of ribosomes is to form proteins from amino acids with the help of mRNA and tRNA. Option B is incorrect because: Cytoplasm is the medium in which chemical reactions take place and in which organelles are present. Option D is incorrect because: The role of Rough ER is to form proteins with the help of ribosomes located on it and transport it to the Golgi Apparatus for modification and packaging.

QUESTION: Which of the following is a chemical link between catabolism and anabolism?
A. AMP
B. ATP
C. ADP
D. All of these
EXPLANATION
Option B is correct because: ATP is the universal energy currency and it is used for all energy requiring processes be it catabolic processes such as respiration or anabolic process such as photosynthesis. Option A is incorrect because: AMP is not the universal energy currency. Option C is incorrect because: ADP is not the universal energy currency. Option D is incorrect because: Option B is correct.

QUESTION: The neurons responsible for converting various external stimuli that come from the environment into corresponding internal stimuli is called:
A. Motor nerve
B. Sensory nerve
C. Both A and B
D. Mixed nerve
EXPLANATION
Option B is correct because: Sensory neurons are responsible for converting external stimuli into electrical impulses to send to the CNS Option A is incorrect because: Motor neurons are responsible for transporting nerve impulses to the effectors. Option C is incorrect because: Option B is correct Option D is incorrect because: Mixed nerves contain both sensory and motor neurons.

QUESTION: What is hepatitis D also known as?
A. Serum hepatitis
B. Infectious hepatitis
C. Bacterial hepatitis
D. Delta hepatitis
EXPLANATION
Option D is correct because: Another name for Hepatitis D is Delta Hepatitis. Option A is incorrect because: Hepatitis B is known as serum hepatitis Option B is incorrect because: Hepatitis A is known as Infectious Hepatitis Option C is incorrect because: Hepatitis is caused by viruses.

QUESTION: The genetic change in a population caused by natural selection is called?
A. polymorphism
B. specialization
C. gene linkage
D. adaptation
EXPLANATION
Option D is correct because: Natural selection exerts a selection pressure on a population and overtime there is a change in genetics of the population called adaptation. Option A is incorrect because: Polymorphism refers to a specific genetic trait being expressed as more than one phenotype. Option B is incorrect because: Specialization refers to organisms adapting their traits to be able to better play a specific role in the environment. Option C is incorrect because: Gene linkage refers to genes close together on a chromosome being inherited together

QUESTION: What protein, present in sarcomeres, is responsible for the passive elasticity of muscle?
A. collagen
B. myosin
C. titin
D. actin and myosin
EXPLANATION
Option C is correct because: Titin is a giant protein, greater than 1 µm in length, that functions as a molecular spring which is responsible for the passive elasticity of muscle. Option A is incorrect because: Collagen provides strength and structure Option B is incorrect because: Myosin is only responsible for muscle contraction Option D is incorrect because: Actin and myosin are only responsible for muscle contraction

QUESTION: Which of the folowing system is well developed in acoelomates?
A. Excretory
B. Nervous
C. Transport
D. Both a and b
EXPLANATION
Option D is correct because: Only the excretory system is developed for the transport of excretory products. This system consists of flame cells, excretory ducts and excretory pores. However the nervous system is well developed. Options A and B are incorrect because: Both these systems are well developed. Option C is incorrect because: In acoelomates the gut is sac-type and there is no special transport system.

QUESTION: In nostrils, the substance which moistens and keep the incoming air warm is called :
A. Bronchi
B. Mucous
C. Pharynx duct
D. Glottis
EXPLANATION
Option B is correct because: Mucous is a slippery aqueous secretion produced by mucous membrane in the nostrils to moisten and warm incoming air as well as trap foreign particles like dust and bacteria. Option A is incorrect because: Bronchi are airways. Option C is incorrect because: Pharynx duct is a duct. Option D is incorrect because: Glottis is an opening into the larynx.

QUESTION: Which statement correctly describes the alimentary canal of hydra?
A. The alimentary canal is formed from the endodermal cells.
B. The alimentary canal has a single opening.
C. The alimentary canal is sac-like.
D. All of the above.
EXPLANATION
Option D is correct because: All the given options describe the alimentary canal of hydra accurately. Options A,B,C are incorrect because: They all together describe the alimentary canal of hydra accurately.

QUESTION: The bicep and tricep muscles are located in:
A. Shank
B. Upper arm
C. Shoulder
D. Lower jaw
EXPLANATION
Option B is correct because: Bicep and tricep muscles are located on the upper arm and are antagonistic in nature. Option A is incorrect because: Bicep and tricep muscles aren’t located here. Option C is incorrect because: Bicep and tricep muscles aren’t located here. Option D is incorrect because: Bicep and tricep muscles aren’t located here.

QUESTION: The genetically engineered vaccine is not available for which of the following?
A. HAV
B. HBV
C. HCV
D. HDV
EXPLANATION
Option C is correct because: There is no vaccine for the virus causing hepatitis C. Option A is incorrect because: Vaccine is available for HAV. Option B is incorrect because: Vaccine is available for HBV. Option D is incorrect because: Vaccine is available for HDV.

QUESTION: During aristotle time, it was thought that
A. Organisms ranged from simple to complex.
B. One type of organism gives rise to another type of organism.
C. Both a and b.
D. All living things are specially created by nature.
EXPLANATION
Option C is correct because: The idea that organisms might evolve through time, with one type of organism giving rise to another type of organism, is an ancient one, existing from the days of Aristotle. Aristotle recognized that organisms ranged from relatively simple to very complex structures. Options A and B are incorrect because: Both of these are correct together. Option D is incorrect because: This was not the theory at Aristotle’s time.

QUESTION: The most abundant intracellular free nucleotide is _____.
A. UTP
B. FAD
C. NAD
D. ATP
EXPLANATION
Option D is correct because: ATP is used for all energy requiring processes in all organisms so it is the most abundant. Option A is incorrect because: UTP is not common. Option B is incorrect because: FAD is used in cellular respiration only in animals so not as common as ATP. Option C is incorrect because: NAD is used in cellular respiration only in animals so it is not as abundant as ATP.

QUESTION: Which one of the following is not part of female reproductive system?
A. Ovary
B. Vagina
C. Urethra
D. Prostate gland
EXPLANATION
Option D is correct because: Prostate gland is only found in males and not present in females. Option A is incorrect because: Ovary is part of the female reproductive system its where the female gamete is released from into the Fallopian tubes. Option B is incorrect because: Vagina is where the sperms are released during intercourse. Option C is incorrect because: Urethra is found in both male and female reproductive systems.

QUESTION: Sperms are developed at what temperature?
A. Lower than the body temperature.
B. Higher than the body temperature.
C. Body temperature.
D. All of the above.
EXPLANATION
Option A is correct because: Sperms are developed in the testis which lie outside of the body in the scrotum to facilitate a temperature lower than the body temperature. Option B is incorrect because: Sperms require a temperature below body temperature to develop. Option C is incorrect because: Sperms require a temperature below body temperature to develop. Option D is incorrect because: Option A is correct.

QUESTION: Which lobe is the back part of the brain that is involved in vision?
A. Frontal
B. Parietal
C. Temporal
D. Occipital
EXPLANATION
Option D is correct because: The occipital lobe is the visual processing area of the brain. It is associated with visuospatial processing, distance and depth perception, color determination, object and face recognition, and memory formation. Option A is incorrect because: The frontal lobes are important for voluntary movement, expressive language and he capacity to plan, organise, initiate, self-monitor and control ones responses. Option B is incorrect because: The parietal lobe is vital for sensory perception and integration, including the management of taste, hearing, sight, touch, and smell. Option C is incorrect because: The temporal lobe plays an important role in processing affect/emotions, language, and certain aspects of visual perception.

QUESTION: During inspiration, the area of the thoracic cavity will
A. Contract
B. Increase
C. Decrease
D. Damage
EXPLANATION
Option B is correct because: As air is taken in the lungs the lungs expand and as a result their volume increases and as a result the area of the thoracic cavity increases. Option A is incorrect because: Question refers to area not movement. Option C is incorrect because: Area of thoracic cavity decreases during exhalation. Option D is incorrect because: Thoracic cavity is not damaged during breathing.

QUESTION: Unit of carbohydrate is ?
A. Monosaccharides
B. Amino acids
C. Fatty acids
D. All
EXPLANATION
Option A is correct because: Simplest subunits of carbohydrates are monosaccharides such as glucose, fructose and galactose. Option B is incorrect because: Amino Acids are subunits of polypeptides and proteins. Option C is incorrect because: Fatty acids are subunits of fats. Option D is incorrect because: Option A is correct.

QUESTION: Which type of viruses infect E.coli bacteria?
A. T phage
B. P phage
C. Both
D. None
EXPLANATION
Option A is correct because: T phages are a species known as bacteriophages that are viruses that attack bacteria, they are only capable of undergoing lytic cycle. T phages attack E. Coli Option B is incorrect because: There are no p phages. Option C is incorrect because: Option A is correct. Option D is incorrect because: Option A is correct.

QUESTION: In the plants, there are 50 or more thylakoids piled upon each other to form?
A. Granum
B. Centrosome
C. Stroma
D. Multinucleate
EXPLANATION
Option A is correct because: Thylakoids in plant cells are stacked on top of each other like flat disks to form a granum. Thylakoid is the site of light collection and where light collecting pigments are situated. Option B is incorrect because: Centrosomes are composed of two centrioles. Option C is incorrect because: Stroma refers to the colourless fluid surrounding the grana within the chloroplast. Option D is incorrect because: Multinucleate refers to cells with more than one nucleus.

QUESTION: In the human body, the group formed by neurons enclosed in the membrane at certain body parts is called?
A. Benign
B. Malign
C. Ganglion
D. Neuroglial
EXPLANATION
Option C is correct because: Ganglia are ovoid structures containing cell bodies of neurons and glial cells supported by connective tissue. Option A is incorrect because: Benign is a term used to describe tumours not being harmful. Option B is not correct because: Malignant is a term used for a tumor that spreads and becomes cancer. Option D is incorrect because: Neuroglia are a large class of neural cells. Neuroglial cells provide homeostatic support, protection, and defense to the nervous tissue.

QUESTION: A pure breeding tall pea plant was crossed to dwarf plant what will be the frequency of dwarf plants in F2?
A. 0.25
B. 0.5
C. 0
D. 1
EXPLANATION
Option A is correct because:

QUESTION: A metal cofactor which is used in synthesis of glycolysis is?
A. Fe+3
B. Mn+2
C. Co+2
D. Mg+2
EXPLANATION
Option D is correct because: Mg2+is a cofactor for many enzymes involved in energy metabolism, including glycolysis and Krebs cycle. Option A,B,C are incorrect because: These are not cofactors for enzymes used in glycolysis.

QUESTION: The rate of reaction is directly proportional to the concentration of an enzyme. Which statement is incorrect in this respect?
A. If the concentration is doubled the rate will become one-fold.
B. If the concentration is doubled the rate will become two-fold.
C. This relation is for an unlimited time period with unlimited enzyme concentration.
D. All of these options are correct.
EXPLANATION
Option A is correct because: Since the concentration of enzyme and the rate of reaction are directly proportional, if one of them doubles the other should double as well due to direct proportionality.

QUESTION: How many actin filaments surround each myosin filament?
A. 2
B. 4
C. 6
D. 8
EXPLANATION
Option C is correct because: In the overlapping region, each thick filament is surrounded by six thin filaments. Options A,B,D are incorrect because: Values are incorrect.

QUESTION: Robert Koch discovered bacteria that cause?
A. Tuberculosis and thyphoid
B. Tuberculosis and measles
C. Tuberculosis and cholera
D. All of the above
EXPLANATION
Option C is correct because: Robert Koch was a German bacteriologist who discovered the bacteria that causes anthrax, septicaemia, tuberculosis and cholera. Option A is incorrect because: Karl Joseph Eberth was the first to describe the bacillus that was suspected to cause typhoid fever in 1880. Option B is incorrect because: Muhammad ibn Zakariya al-Razi discovered measles. Option D is incorrect because: Option C is correct

QUESTION: Sperms are produced in:
A. Urethra
B. Pancreas
C. Sperm duct
D. Testis
EXPLANATION
Option D is correct because: Within the testes are coiled masses of tubes called seminiferous tubules. These tubules are responsible for producing the sperm cells through a process called spermatogenesis. Option A is incorrect because: Urethra is the urogenital tract where the sperms pass through from to the outside of the body. Option B is incorrect because: Pancreas produce various hormones. Option C is incorrect because: Sperm duct is the tube which carries the sperm from the epididymis.

QUESTION: In a typical menstrual cycle of 28 days, what is the most likely fertile period?
A. Days 5 to 10
B. Days 1 to 5
C. Days 14 to 15
D. Days 11 to 14
EXPLANATION
Option D is correct because: Sperms can survive inside the female body for 5 days and the woman ovulates on day 14 hence making days 11 – 14 the most fertile period. Option A is incorrect because day 5 – 10 is the proliferative phase where the follicle is still maturing. Option B is incorrect because day 1 – 5 is the menstruation period where the endometrium lining sheds and passes through the female body as menses. Option C is incorrect because: Eggs only survive from 12- 24 hours after they are released so they must get fertilized during this time interval and sperms only survive 5 days inside the female body so days 14 – 15 are not the most fertile period.

QUESTION: Which portion of the brain is primarily responsible for processing and interpreting information:
A. White matter
B. Gray matter
C. Medulla
D. All A, B and C
EXPLANATION
Option B is correct because: Grey matter contains most of the brains neuronal cell bodies. The grey matter includes regions of the brain involved in muscle control, and sensory perception such as seeing and hearing, memory, emotions, speech, decision making, and self-control. Option A is incorrect because: The white matter contains the white fatty myelin which is important for the insulation of the axons. This allows faster signal transport and directly affects the normal sensory and motor functions. Option C is incorrect because: Medulla plays an essential role in passing messages between your spinal cord and brain. Its also essential for regulating your cardiovascular and respiratory systems. Option d is incorrect because: Option B is correct.

QUESTION: Bacteriochlorophylls does not include which of the following?
A. Chlorophyll a
B. Chlorophyll b
C. Chlorophyll c
D. All of these
EXPLANATION
Option D is correct because: Bacteriochlorophylls are different from chlorophyll found in algae, plants and cyanobacteria. Bacteriochlorophyll and chlorophyll are similar in the overall structure. But they differ in the substitutions around the ring and in the length and substitutions on the phytol tail. Options A,B,C are incorrect because: These are chlorophylls found in algae, plants and cyanobacteria.

QUESTION: Haemoglobin molecule exhibits which structural organization of proteins?
A. Primary structure
B. Secondary structure
C. Tertiary structure
D. Quaternary structure
EXPLANATION
Option D is correct because: Hemoglobin has more than 2 polypeptide chains (it has 4) folded in a 3D shape it also has ionic, hydrogen, disulphide bonds and weak hydrophobic interactions hence it is a quaternary structure. Option A is incorrect because: Primary structure is just the sequence of amino acids in a polypeptide. Option B is incorrect because: Secondary structure refers to regular, recurring arrangements such as alpha helix and beta pleated sheets between adjacent amino acids in a polypeptide chain. It is maintained by hydrogen bonds. Option C is incorrect because: Protein tertiary structure is the three dimensional shape of a protein. The tertiary structure will have a single polypeptide chain.

QUESTION: 60S and 40S subunits combine to form what size particle?
A. 80S
B. 90S
C. 100S
D. 110S
EXPLANATION
Option A is correct because: 60S and 40S ribosome subunits form 80S ribosomes in Eukaryotes. In prokaryotes 50S and 30S ribosome subunits combine to form 70S ribosomes. Options B,C,D are incorrect because: 90S, 100S and 110S are formed from different subunits.

QUESTION: The cell organelles involved, in some cases, with extra-cellular digestion _________ .
A. Golgi complex
B. Lysosomes
C. Peroxisomes
D. Glyoxysomes
EXPLANATION
Option B is correct because: Lysosomes are membrane bound organelles which contain hydrolytic enzymes used for digestion inside the cells and outside the cells (extra cellular digestion). Option A is incorrect because: Lysosomes bud off from the golgi complex but the golgi complex itself isn’t involved in any digestion. Option C is incorrect because: Peroxisomes contain enzymes that oxidize certain molecules such as acids and amino acids. Those oxidation reactions produce hydrogen peroxide. Option D is incorrect because: Glyoxysomes are specialized peroxisomes found in plants (particularly in the fat storage tissues of germinating seeds).

QUESTION: Concept of evolution was first presented by which of the following scientists?
A. Lamark
B. Darwin
C. Wallace
D. Aristotle
EXPLANATION
Option A is correct because: Lamarck’s theory of evolution was the first one in the early 19th century which was followed by other theories. Option B and C are incorrect because: Darwin and Wallace published theories came after Lamarck’s. Option D is incorrect because: Aristotle did not believe in evolution.

QUESTION: Circulatory system is open type in all of the following except?
A. Arthropoda
B. Gastropoda
C. Pelecypoda
D. Cephalopoda
EXPLANATION
Option D is correct because: Cephalopods are the only molluscs with a closed circulatory system. This means that blood flows through a series of vessels to return to the heart, rather than bathing organs in the blood fluid as in open circulatory systems. Option A,B,C are incorrect because: They all have open circulatory systems.

QUESTION: All of the following is true about bacilli bacteria except?
A. All bacilli are gram positive.
B. All bacilli are aerobic.
C. All bacilli are rod-shaped.
D. Both A and B.
EXPLANATION
Option D is correct because: Bacillus species are rod-shaped, endospore-forming aerobic or facultatively anaerobic, Gram-positive bacteria. Option A and B are incorrect because: Both of these are not true about bacillus bacteria. Option C is incorrect because: All bacilli are rod shaped.

QUESTION: The function of tropomyosin is to prevent actin and myosin from - when the muscle is at rest.
A. Interacting
B. Separation
C. Both A an B
D. None of these
EXPLANATION
Option A is correct because: At rest tropomyosin covers the myosin binding sites on the actin filament preventing any interaction between myosin heads and their binding site on the actin filament. Option B is incorrect because: Tropomyosin doesn’t prevent separation as that takes place during contraction of muscle and energy in the form of ATP is used to separate myosin heads from the binding sites on actin filament. Option C and D are incorrect because: Only option A is correct.

QUESTION: Glycophorin is involved in whcih of the following disease?
A. Viral fever
B. Common cold
C. Asthma
D. Malaria
EXPLANATION
Option D is correct because: Genome-wide association studies have shown that resistance to malaria may be connected with human glycophorin ABE locus [20], suggesting that glycophorins play an important role in erythrocyte invasion by Plasmodium malaria parasites. Options A,B,C are incorrect because: These diseases aren’t associated with Glycophorin

QUESTION: The bacteriophage is shaped as?
A. Rod
B. Spherical
C. Tadpole
D. Helical
EXPLANATION
Option C is correct Option A,B,D are incorrect because: These are shapes of bacteria and not bacteripgahes.

QUESTION: A botanist sees that when he breeds a plant with blue flowers with a plant with red flowers, the resulting generation are plants that all have a 1:1 ratio of blue:red flowers. He knows that the two parents are homozygous for the trait of color. What phenomenon most likely explains the 1:1 ratio in the filial generation?
A. Incomplete dominance
B. Independent assortment
C. Penetrance
D. Codominance
EXPLANATION
Option D is correct because: Codominance occurs when both the alleles express independently in heterozygote. The codominant heterozygote would have both substances at the same time. Option A is incorrect because: In incomplete dominance, the alleles are not expressed as dominant or recessive; rather, the dominant allele is expressed in a reduced ratio. Like a red and white flower cross producing a pink flower Option B is incorrect because: Independent Assortment of chromosomes is does not explain the different types of inheritance Option C is incorrect because: Penetrance measures the proportion of individuals in a population who carry a specific gene and express the related trait.

QUESTION: In human, the total inside capacity of lungs is about:
A. 3.5 litres
B. 2.5 litres
C. 5 litres
D. 10 litres
EXPLANATION
Option C is correct because: In an adult human being when the lungs are fully inflated the total inside capacity of lungs is about 5 litres. Option A is incorrect because: The volume of air taken inside the lungs and expelled during exercise is about 3.5 litres Option B and D are incorrect because: These values are wrong for total inside capacity of lungs

QUESTION: Which of the following types of bacterial reproduction is most similar to mitosis?
A. Transduction
B. Transformation
C. Binary fission
D. Conjugation
EXPLANATION
Option C is correct because: Binary fission and mitosis are both forms of asexual reproduction in which a parent cell divides to form two identical daughter cells. Binary fission occurs primarily in prokaryotes (bacteria), while mitosis only occurs in eukaryotes (e.g., plant and animal cells) Options A,B and D are incorrect because: These are ways of exchanging genetic information between bacteria

QUESTION: The flap like structure found in larynx is called:
A. Glottis
B. Epiglottis
C. Larynx
D. Vocal cords
EXPLANATION
Option B is correct because: The epiglottis is a flap of cartilage located in the throat behind the tongue and in front of the larynx. The epiglottis is usually upright at rest allowing air to pass into the larynx and lungs. Option A is incorrect because: The glottis is the opening between the vocal cords in the larynx Option C is incorrect because: Larynx is the voice box containing vocal chords Option D is incorrect because: These are folds of membranous tissue whose edges vibrate in the airstream to produce the voice.

QUESTION: If muscle contracts upon stimulation, calcium ions bind to _________, which exposes the binding sites for the myosin cross-bridges to attach to.
A. Actin
B. Myosin
C. Troponin
D. Sarcomere
EXPLANATION
Option C is correct because: When the muscle is required to contract, calcium ions bind with the troponin molecule and cause them to move slightly. This has the effect of displacing the tropomyosin and exposing the binding sites for the myosin head. Option A is incorrect because: Actin has binding sites for myosin heads, calcium ions do not bind to actin filaments. Option B is incorrect: Myosin heads bind to actin filament during muscle contraction, calcium ions do not bind to myosin. Option D is incorrect: A sarcomere is the basic contractile unit of muscle fiber.

QUESTION: What are the end products of the ETC in animals?
A. ATP
B. Carbon dioxide
C. Water
D. Both Options A and C are correct
EXPLANATION
Option D is correct because: ATP is produced as a result of chemiosmosis in the mitochondrial membrane via ATP synthase located in the stalked particle. Water is produced due to oxygen being the final electron acceptor. As a result, oxygen accepts the electrons from the ETC along with protons to form water. C₆H₁₂O₆+ 6O₂→ 6CO₂+ 6H₂O + energy. Options A and C are incorrect because both of these are end products of the ETC. Option B is incorrect because carbon dioxide is a byproduct of cellular respiration as a whole.

QUESTION: The composition of the white matter of the spinal cord is:
A. Myelinated dendrite
B. Non-myelinated dendrite
C. Non-myelinated axon
D. Myelinated axon
EXPLANATION
Option D is correct because: The white matter in the spinal cord is myelinated axons. The myelin sheath on axons gives white matter the white colour due to having fats and proteins in it. Option A and B are incorrect because: Dendrites are not myelinated. Option C is incorrect because: The white in white matter is myelin sheath on axons insulating axons.

QUESTION: The oldest mineral discovered so far is which of the following, which dates back to 4.4 billion years.
A. Iron
B. Zircon
C. Diamond
D. Cadmium
EXPLANATION
Option B is correct because: The oldest material of terrestrial origin that has been dated is a zircon mineral. Option A is incorrect because: iron is a metal. Options C and D are incorrect because: These minerals are not as old as zircon.

QUESTION: Which type of bonds are never formed when a substrate fits into the active site of an enzyme?
A. Hydrogen bonds
B. Ionic interactions
C. Hydrophobic interactions
D. Covalent linkage
EXPLANATION
Option D is correct because: Once the correct substrate has bound at the active site of the enzyme, an enzyme-substrate complex is created. Sometimes the substrate is held in the complex by combinations of ionic bonds, hydrophobic interaction, or hydrogen bonding between and from the amino acids. Options A,B,C are incorrect because: These bonds are formed in an enzyme substrate complex.

QUESTION: The canal system in sponges develops due to which of the following?
A. Porous walls
B. Gastrovascular system
C. Reproduction
D. Folding of inner wall
EXPLANATION
Option D is correct because: In most sponges the inner layer choanoderm is made of flagellated cells called choanocytes. There is a single cavity inside the body, the spongocoel. In most sponges the spongocoel may be divided into flagellated chambers or canals, lined by flagellated choanocytes. Option A is incorrect because: In most sponges the body wall is formed of an outer layer, pinacoderm, made up of cells called pinacocytes. Options B and C are incorrect because: These options don’t fit the type of answer required.

QUESTION: Normal human blood is about:
A. 15ml/100ml of blood
B. 19.6ml/100ml of blood
C. 20ml/100ml of blood
D. 200ml/100ml of blood
EXPLANATION
Option B is correct because: When an oxygen tension is 115mm mercury, haemoglobin is 98 percent saturated and, therefore, contains 19.6 ml of oxygen per 100ml of blood. This means that haemoglobin can be almost completely oxygenated by an oxygen pressure of 100 mm mercury, which is present in the lungs. Options A,C and D are incorrect because: The values are incorrect.

QUESTION: Two populations of the same species over time grow distant from one another. At what point will these two populations be considered different species?
A. When the populations begin to eat different foods.
B. When there is a physical barrier, such as river, between the two populations.
C. When the two populations have not been in contact with one another for two hundred years.
D. When they are no longer able to interbreed.
EXPLANATION
Option D is correct because: Speciation occurs when two groups of animals are unable to interbreed to produce a fertile viable offspring. Option A is incorrect because: This has nothing to do with speciation. Option B and C are incorrect because: these can lead to speciation but arent the determining factor.

QUESTION: What is the chemical characteristic of auxins?
A. Indole propionic acid
B. Indole carboxylic acid
C. Indole acetaldehyde
D. Indole acetic acid
EXPLANATION
Option D is correct because: Auxins are Indole Acetic Acid or its variants. Options A,B and C are incorrect because: These are not auxins.

QUESTION: Globular proteins differ from fibrous proteins in?
A. Non-crystalline
B. More amino acids
C. Peptide bonds
D. Soluble in aqueous medium
EXPLANATION
Correct option D This option is correct because fibrous protein are insoluble in aqueous medium where as globular proteins are covered by amino acids which are polar in nature that is why globular proteins are water soluble.

QUESTION: The uterine tube opens into:
A. Uterus
B. Ovary
C. Cervix
D. Oviduct
EXPLANATION
Option A is correct because: The zygote travels from the uterine tube or oviduct or fallopian tube into the uterus where it gets implanted onto the lining of the uterus. Option B is incorrect because: Egg released from the ovary goes into the uterine tube. Option C is incorrect because: The cervix is a cylinder-shaped neck of tissue that connects the vagina and uterus. Located at the lowermost portion of the uterus. Option D is incorrect because: Oviduct is another name for uterine tube or fallopian tube.

QUESTION: During the lytic cycle, how many phages are released from the infected host cell?
A. 100-300
B. 100-500
C. 100-200
D. 100-400
EXPLANATION
Option A is correct because: During the lytic cycle, 100-300 phages are released into the environment.

QUESTION: A diploid cell has two sets of chromosomes, what is the diploid number of a human somatic cell if one human gamete has 23 chromosomes?
A. 44
B. 45
C. 46
D. 43
EXPLANATION
Option C is correct because: 23x2= 46 Options A,B and D are incorrect because: These values are incorrect.

QUESTION: The envelope of an enveloped virus is derived from?
A. The mitochondrion of the cell
B. Cell membrane of the host cell
C. Endoplasmic reticulum of the cell
D. None of these
EXPLANATION
Option B is correct because: In some animal viruses the nucleocapsid (nucleic acid and capsid) is covered by another membrane derived from the host cell membrane, the envelope. Options A and C are incorrect because: Viruses do not derive their envelope from membranes of organelles. Option D is incorrect because: Option B is correct.

QUESTION: The optimum pH for enzyme arginase is?
A. 9
B. 9.3
C. 9.7
D. 10
EXPLANATION
Option C is correct because:

QUESTION: Which of the following is false regarding the bacterial membrane?
A. Bacteria contain plasma membranes that are made up of triglycerides.
B. Gram staining reveals that bacteria contain cell walls, but no cell membranes.
C. Bacteria do not contain a membrane-bound nucleus, but they contain an analogous membrane-bound structure called the nucleoid.
D. All of these.
EXPLANATION
All cells, including bacterial cells have a cell membrane. It is made up of a thin phospholipid bilayer with several different types of integral proteins embedded within NOT triglycerides. Bacteria are prokaryotic organisms that do not contain any membrane-bound organelles; however, they do contain a cell wall and a plasma membrane as outer coverings for containment. Hence D is the answer as all of the following statements are false.

QUESTION: The solids which does not possess the regular arrangement of atoms are called as ________?
A. Amorphous solids
B. Crystalline solids
C. Polymorphic solids
D. Isomorphic solids
EXPLANATION
Option A is correct because: Amorphous substances are those whose constituent atoms, ions, or molecules do not possess a regular orderly arrangement. The best examples are glass, plastics, rubber, glue, etc. Option B is incorrect because: Those solids in which atoms, ions or molecules are arranged in a definite three-dimensional pattern are called crystalline solids. Option C is incorrect because: That compound which exists in more than one crystalline form is called polymorphic. Option D is incorrect because: Isomorphism is the phenomenon in which two different substances exist in the same crystalline form. These different substances are called isomorphs of each other.

QUESTION: Formation of Hydrogen molecule according to VBT theory involves overlap of
A. 1s orbital
B. 2s orbital
C. 2P orbital
D. 2px orbital
EXPLANATION
Option A is correct because: In the formation of a hydrogen molecule, according to VB theory the two atoms approach each other, their 1s orbitals overlap, thereby giving the H-H bond. Options B,C,D are incorrect because: Hydrogen atom does not have these orbitals.

QUESTION: The negative ions having group of atoms is/are
A. OH-
B. C032-
C. Cr2072-
D. All of these
EXPLANATION
Option D is correct because: All of the compounds options have more than one atom and hence are negatively charged ions with a group of atoms. Options A,B,C are incorrect because: Option D is correct.

QUESTION: Which one is not member of Alkali metals?
A. Na
B. K
C. Cs
D. Mg
EXPLANATION
Option D is correct because:

QUESTION: The specific site at which substrate is attached on the enzyme and converted into product is called as?
A. Reaction site
B. Active site
C. Binding site
D. None of these
EXPLANATION
Option B is correct because: Each enzyme molecule possesses a region known as the active site and the substrate binds itself with this active site. Option A is incorrect because: This is part of the active site. Option C is incorrect because: This is part of the active site. Option D is incorrect because: Option B is correct.

QUESTION: Which functional group does amino acid contain?
A. Carbonyl group
B. Ester and Alkyl halide
C. Carboxylic acid
D. Carboxylic acid and Amine functionality
EXPLANATION
Option D is correct because:

QUESTION: Which of the following Halogens react fast with alkanes in substitution reactions?
A. Cl₂
B. F₂
C. I₂
D. Br₂
EXPLANATION
Option B is correct because: The reactivity of the halogens decreases in the following order: F₂ > Cl₂ > Br₂ > I₂. Fluorine is so explosively reactive it is difficult to control, and iodine is generally unreactive. Options A,C,D are incorrect because: These halogens are less reactive with alkanes than fluorine.

QUESTION: Manufacturing of Ammonia by Habers process is an
A. Endothermic reaction
B. Exothermic reaction
C. Irreversible
D. Slow
EXPLANATION
Option B is correct because: The Haber process is a type of exothermic reaction because heat energy is released during the formation of ammonia gas from nitrogen and hydrogen gases. Option A is incorrect because: Heat is given off during the reaction and in endothermic heat is absorbed. Option C is incorrect because: The reaction is reversible and can go in both directions. N₂+3H₂ ⇌ 2NH₃ Option D is incorrect because: The Catalyst in the reaction makes the reaction fast by quickly making the reaction achieve equilibrium.

QUESTION: Which of the following term is constant in Boyles law?
A. Pressure
B. Temperature
C. Volume
D. Density
EXPLANATION
Option B is correct because: Boyles law states the volume of a gas at constant temperature varies inversely with the pressure exerted on it. Option A is incorrect because: Pressure is varied. Option C is incorrect because: Volume is varied. Option D is incorrect because: Density varies with volume.

QUESTION: In IUPAC nomenclature alkyl halides are named as ________?
A. Alkyl Halogens
B. HalogenoAlkanes
C. Haloalkanes
D. Alkyl halides
EXPLANATION
Option C is correct because: The IUPAC system uses the name of the parent alkane with a prefix indicating the halogen substituents, followed by the number indicating the substituents location. The prefixes are fluoro-, chloro-, bromo-, and iodo-. Hence CH₃CH₂Cl has the common name ethyl chloride and the IUPAC name chloroethane. Option A is incorrect because: Not the IUPAC nomenclature (common names). Option B is incorrect because: Not the IUPAC nomenclature (common names). Option D is incorrect because: Not the IUPAC nomenclature (common names).

QUESTION: The slope of the curve obtained by plotting concentration change with time is actually
A. Reaction time
B. Reaction Speed
C. Rate of reaction
D. All of these
EXPLANATION
Option C is correct because: The rate of reaction at any particular time is found as the gradient of the concentration vs. time graph at the particular time. Option A is incorrect because: Time is the x axis in the concentration time graph. Option B is incorrect because: Speed of the reaction is the rate of a reaction. Option D is incorrect because: Only option C is correct.

QUESTION: The phenomenon in which compounds have same molecular formula but different structural formula is called as ?
A. Reforming
B. Isomerism
C. Polymorphism
D. Hybridization
EXPLANATION
Option B is correct because: Isomerism is a very common phenomenon in organic compounds. Very often more than one compound is represented by the same molecular formula. However, they have different structural formulas. Option A is incorrect because: It is the improving of octane number of gasoline. Option C is incorrect because: Polymorphism is a phenomenon in which a compound exists in more than one crystalline form. Option D is incorrect because: Hybridisation is the concept of mixing atomic orbitals to form new hybrid orbitals suitable for the pairing of electrons to form chemical bonds in valence bond theory.

QUESTION: The Diameter of DNA is maintained due to _________?
A. Dipole dipole forces
B. Induced dipole forces
C. Chemical bond
D. H-bond
EXPLANATION
Option D is correct because: DNA molecules have uniform diameter due to specific base pairing between nitrogenous bases. In DNA, the bases form hydrogen bonds. Options A,B,C are incorrect because: These bonds are not formed between nitrogenous bases.

QUESTION: Which of the following product is obtained from the Chlorination of acetylene?
A. 1,2,3,4-Tetrachloroethylene
B. 1,1,2,2-Tetrachloroethylene
C. 1,1,2,2-Tetrachloroethane
D. 1,2,3,4-Tetrachloroethylene
EXPLANATION
Option C is correct because: Options A,B,D are incorrect because: These are halo alkenes.

QUESTION: Maximum Hydrogen bonding is found in
A. HI
B. HF
C. HCL
D. HBr
EXPLANATION
Option B is correct because: Fluorine is the most electronegative halogen hence it will have the strongest hydrogen bond. Option A is incorrect because: Not as electronegative as fluorine. Option C is incorrect because: Not as electronegative as fluorine. Option D is incorrect because: Not as electronegative as fluorine.

QUESTION: Two cotton plugs soaked in HCI and NH₃ solutions are introduced in the open ends of glass tube ,1 cm long. Which gas travels fast?
A. HCL
B. NH₃
C. Equally
D. Both
EXPLANATION
Option B is correct because: The molecular mass of NH₃ (17) is much lower than HCl (36.5) as a result the NH₃ gas travels and diffuses faster. Option A is incorrect because: HCl has a higher molecular mass than NH₃ Option C is incorrect because: For this both molecular masses have to be the same. Option D is incorrect because: HCl travels slow due to its molecular mass.

QUESTION: The solution of phenol in water has a pH of about?
A. 4-5
B. 3-5
C. 2-4
D. 5-6
EXPLANATION
Option D is correct because: The pH of a typical dilute solution of phenol in water is around 5 - 6. Options A,B,C are incorrect because: Wrong pH.

QUESTION: When an electron changes its orbit from outer to inner level, energy is ?
A. No change
B. Absorbed
C. Released
D. Remains constant
EXPLANATION
Option C is correct because: Energy is released because outer orbits have a higher energy than inner orbits hence electrons jumping from a higher energy orbit to a lower energy orbit release energy. Option A is incorrect because: This would be the case of an electron jumping between same energy orbits. Option B is incorrect because: Energy would be absorbed jumping from low energy orbit to high energy orbit. Option D is incorrect because: This would be the case of an electron jumping between same energy orbits.

QUESTION: The increase in size of an anion is due to Increase in repulsion of ?
A. Electron-proton
B. Electron-electron
C. Electron-nucleus
D. Proton-nucleus
EXPLANATION
Option B is correct because: In an anion the extra electron or electrons are repelled by the electrons in the lower orbits and as a result the distance between the nucleus and valence electron increases increasing the size of the anion. Option A is incorrect because: Electron and proton attract. Option C is incorrect because: electron and nucleus attract. Option D is incorrect because: There is no attraction or repulsion between proton and neutron.

QUESTION: The side of the manometer in which mercury rises faces the?
A. Atmosphere
B. Liquid
C. Container
D. Gas
EXPLANATION
Option A is correct because:

QUESTION: Which one of them can conduct electricity in solid state?
A. Diamond
B. Graphite
C. Nail
D. Iodine
EXPLANATION
Option B is correct because: In graphite each carbon is bonded to three other carbon atoms hence leaving behind a free electron. Due to the presence of this one delocalised electron, graphite is a good conductor of electricity. Option A is incorrect because: Every atom in a diamond is bonded to its neighbours by four strong covalent bonds, leaving no free electrons and no ions. Option C is incorrect because: Option does not make sense. Option D is incorrect because: Iodine does not conduct electricity since each molecule of iodine comprises two iodine atoms joined by a covalent bond that cannot be excited sufficiently to transfer electrical energy.

QUESTION: What is the Hybridization of carbon in ethene?
A. sp²
B. sp³
C. sp
D. None of these
EXPLANATION
Option A is correct because: In ethene molecules, the carbon atoms are sp² hybridized. One unpaired electron in the p orbital remains unchanged. Option B is incorrect because: This hybridization is in ethane. Option C is incorrect because: This hybridization is in ethyne. Option D is incorrect because: Option A is correct.

QUESTION: Heat exchanged between the system and surrounding at constant volume is shown by the relation?
A. ∆H= qv+ w
B. ∆E= (q)v
C. ∆H=(q)v
D. ∆E= (q)v + PV
EXPLANATION
Option B is correct because: ∆ E = q - P V. When the volume of the gas is not allowed to change, then ∆V = 0 and the equation will take the following form. ∆E = (q) v. Options A,C,D are incorrect because: Wrong equations.

QUESTION: Which one the characteristic of Ionic solids?
A. High vapor pressure
B. Good conductivity
C. Low melting point
D. Solubility in polar solvents
EXPLANATION
Option D is correct because: Ionic substances are generally most soluble in polar solvents; the higher the lattice energy, the more polar the solvent must be to overcome the lattice energy and dissolve the substance. Because of its high polarity, water is the most common solvent for ionic compounds. Option A is incorrect because: Ionic solids have low vapour pressure as they cannot be vapourised quickly because they have very strong intermolecular forces holding the molecules together in a crystalline structure. Option B is incorrect because: Ionic compounds are excellent conductors of electricity only in aqueous or molten state. Option C is incorrect because: Ionic compounds are held together by electrostatic forces between the oppositely charged ions. As the ionic lattice contains such a large number of ions, a lot of energy is needed to overcome this ionic bonding so ionic compounds have high melting and boiling points.

QUESTION: In nomenclature, aldehyde group in all aldehydes are given position 1 and its position is not mentioned in the name because?
A. Aldehyde is given priority.
B. Aldehyde is parent.
C. Aldehyde group is present at terminal.
D. None of these
EXPLANATION
Option C is correct because: The Aldehyde group is always present at the terminal end of the carbon chain so it also receives the first carbon position and its position does not need to be named. Options A,B,D are incorrect because: These options rent the reason.

QUESTION: Alcohol is dehydrated by the following reaction:
A. Elimination reaction
B. Oxidation reaction
C. Combustion
D. Decomposition
EXPLANATION
Option A is correct because: Tertiary alcohols in the presence of acid dichromate undergo elimination reactions to give alkenes. They get dehydrated to form alkenes. Option B is incorrect because: Oxidation of alcohols convert them into aldehydes and ketones. Option C is incorrect because: Complete combustion of alcohols produces carbon dioxide gas and water vapour. Option D is incorrect because: Most alcohol is broken down, or metabolised, by an enzyme in your liver cells known as alcohol dehydrogenase (ADH). ADH breaks down alcohol into acetaldehyde, and then another enzyme, aldehyde dehydrogenase (ALDH), rapidly breaks down acetaldehyde into acetate.

QUESTION: When CH₃CH₂MgBr reacts with C0₂ which of the following product is formed?
A. CH₃CH₂CH₂CH₂0H
B. CH₃CH₂CH₂0H
C. CH₃CH₂COOH
D. CH₃CH₂CH₂Br
EXPLANATION
Option C is correct because: Grignard’s reagent reacts with CO₂ to form carboxylic acids. Options A,B,D are incorrect because: These are not carboxylic acids.

QUESTION: What is the general formula of Aldehyde?
A. RCOR
B. RCOOR
C. RCHO
D. RCOOH
EXPLANATION
Option C is correct because: Aldehydes have this general formula at terminal ends of the carbon chain. Option A is incorrect because: This is the general formula for ketones. Option B is incorrect because: This is the general formula for esters. Option D is incorrect because: this is the general formula for carboxylic acids.

QUESTION: The species which donates electrons to the central metal atom in the coordination sphere is called?
A. Anion
B. Cation
C. The ligand is positively charged
D. Acid
EXPLANATION
Option C is correct because: The atoms or ions or neutral molecules, which surround the central metal ion and donate electron pairs to it, are called ligands. Option A is incorrect because: Ligands may be anions or neutral molecules. Option B is incorrect because: Cations are positively charged hence cannot donate electrons. Option D is incorrect because: Acids are proton donating species.

QUESTION: Addition of 2% gypsum in cement leads to:
A. Hydration
B. Hydrolysis
C. Preventing of rapid hardening
D. All of the above options are correct
EXPLANATION
Option C is correct because: Gypsum is often added to cement to prevent early hardening or “flash setting”, allowing a longer working time. Gypsum slows down the setting of cement so that cement is adequately hardened. Options A and B are incorrect because Gypsum does not bring around these actions. Option D is incorrect because Option C is correct.

QUESTION: What is the value of molecularity and oder of SN₁ reactions?
A. 2,1
B. 1,1
C. 0,1
D. 0,2
EXPLANATION
Option B is correct because: SN₁ reaction has first order kinetics, because the rate determining step involves one molecule splitting apart, not two molecules colliding. Since it is a unimolecular reaction its molecularity is also 1. Options A,C,D are incorrect because: These values are wrong.

QUESTION: Rate equation for the hydrolysis of Tertiary Butyl Bromide is independent of concentration of water as a reactant because?
A. Its in excess
B. A solvent
C. Solute
D. Both A and B
EXPLANATION
Option D is correct because: The rate of reaction remains effectively independent of the concentration of water because, being a solvent, it is present in very large excess. Such type of reactions have been named as pseudo first order reactions. Options A and B are incorrect because: They both are true for the question. Option D is incorrect because: Water is used as a solvent.

QUESTION: Alicyclic compounds are similar in properties to __________?
A. Heterocyclic compounds
B. Aliphatic compounds
C. Acyclic compounds
D. Aromatic compounds
EXPLANATION
Option B is correct because: Alicyclic compounds are those ring compounds that contain a carbon atom at each corner of the ring. Their properties are similar to those of the corresponding open chain compounds and their cyclic structure. Option A is incorrect because: A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements as members of its ring so is not similar to Alicyclic compounds. Option C is incorrect because: These are open chained compounds with no ring structure and so are very different to Alicyclic compounds. Option D is incorrect because: Alicyclic compounds don’t show the same properties as aromatic compounds.

QUESTION: Which of the following properties is not related to transition metals ________?
A. Complex formation
B. Color
C. Fixed valency
D. D-orbital
EXPLANATION
Option C is correct because: Transition metals have a variable oxidation state due to not having a completely filled d - subshell. Option A is incorrect because: Transition metals form complex compounds. Option B is incorrect because: Transition metals form colored compounds. Option D is incorrect because: Transition metals have a partially filled d - subshell.

QUESTION: Polyvinyl acetate is polymer of _______?
A. Acetyl acetate
B. Vinyl acetate
C. Chloro acetate
D. Benzyl acetate
EXPLANATION
Option B is correct because: Polyvinyl acetate is prepared by the polymerization of the vinyl acetate monomer, through free radical vinyl polymerization of the vinyl acetate monomer. Options A,C,D are incorrect because: These are not the monomers of Polyvinyl Acetate.

QUESTION: Enthalpy of a system is also called as _________?
A. Entropy
B. Work function
C. Total heat content
D. Internal energy
EXPLANATION
Option C is correct because: The total heat content of a system is termed as enthalpy of a system. Option A is incorrect because: Entropy is the measure of the disorder of a system. Option B is incorrect because: Work function is a physics term. Option D is incorrect because: The total of all the possible kinds of energies of the system is called its internal energy.

QUESTION: Masses of enzymes is between _________?
A. Thousands
B. Millions
C. Hundreds
D. Billions
EXPLANATION
Option B is correct because: Typically enzymes are macromolecules with molecular masses ranging into millions. Options A,C,D are incorrect because: The values are wrong.

QUESTION: The name protein is derived from ___________ word proteios meaning _________?
A. Greek, Important
B. French, Prime Importance
C. Greek, Functional
D. Greek, Prime Importance
EXPLANATION
Option D is correct because: The name protein is derived from the Greek word proteios meaning of prime importance. (Punjab board chem chapter macromolecules).

QUESTION: Atomicity is determined by number _________ of present in a molecule.
A. Dots
B. Atoms
C. Sub particles
D. Electrons
EXPLANATION
Option B is correct because: A molecule is the smallest particle of a pure substance which can exist independently. It may contain one or more atoms. The number of atoms present in a molecule determines its atomicity. Thus molecules can be monatomic, diatomic and triatomic, etc. Options A,C,D are incorrect because: Atomicity is not determined by these.

QUESTION: During SN₁ mechanism, nucleophile can attack on the halogen carbon?
A. From opposite side of leaving group
B. From front of leaving group
C. From both sides
D. None of these
EXPLANATION
Option C is correct because: In the SN₁ mechanism, the nucleophile attacks when the leaving group has already gone, so the question of the direction of the attack does not arise. Moreover, the intermediate carbocation is a planar species allowing the nucleophile to attack it from both directions with equal ease. Option A is incorrect because: In SN₂ nucleophile attacks from the side which is opposite to the leaving group. Option B is incorrect because: This does not happen in either SN₁ or SN₂ reactions. Option D is incorrect because: Option C is correct.

QUESTION: The rate of reaction between two specific time intervals is?
A. Instantaneous rate
B. Constant rate
C. Average Rate
D. All of these
EXPLANATION
Option C is correct because: The rate of reaction between two specific time intervals is called the average rate of reaction. (Punjab chem reaction kinetics). Option A is incorrect because: The rate at any one instant during the interval is called the instantaneous rate. Option B is incorrect because: When something has a constant rate of change, one quantity changes in relation to the other. Option D is incorrect because: Option C is correct.

QUESTION: Heat of solution for NaCl is ?
A. High
B. Low
C. Zero
D. One
EXPLANATION
When 1 mole of sodium chloride crystals are dissolved in an excess of water, the enthalpy change of solution is found to be +3.9 kJ mol-1. The change is slightly endothermic, and so the temperature of the solution will be slightly lower than that of the original water.

QUESTION: NucleophiIic reactions of carboxylic acids are due to __________?
A. Presence of OH bond
B. Presence of C-O single bond
C. Presence of C-O double bond
D. None of these
EXPLANATION
Option C is correct because: The carbonyl group (C=O) gets polarized (i.e. there is a charge separation), since oxygen is more electronegative than carbon and pulls the electron density towards itself as a result a carbocation forms susceptible to nucleophilic attack. Option A is incorrect because: Carboxylic acids undergo a nucleophilic substitution reaction where the nucleophile (-OH) is substituted by another nucleophile (Nu). Option B is incorrect because: C-O single bond does not participate in the reaction. Option D is incorrect because: Option C is correct.

QUESTION: The Ionic radii appeared to be a/an ______ property.
A. Associative
B. Multiplicative
C. Additive
D. All of these
EXPLANATION
Option C is correct because: The interionic distance ‘R’ in a crystal lattice is equal to the sum of the cationic radius r⁺ and the anionic radius r. R = r + + r - Pauling was able to determine the distance between K⁺ and Cl^- ions in potassium chloride crystal and found that it was equal to the sum of the radii of the two ions. R = 133pm + 181 pm = 314 pm Thus, the ionic radius appeared to be an additive property. (Punjab board chem chapter chemical bonding)

QUESTION: Which of the following isomerism is shown by Alkynes?
A. Positional isomerism
B. Geometrical isomerism
C. Cis-trans isomerism
D. Functional group isomerism
EXPLANATION
Explanation for this question will be added shortly.

QUESTION: Slope of the curve can be determined by ?
A. Area under the curve
B. Calculating length of curve
C. Drawing a tangent to the curve
D. All of these
EXPLANATION
Option C is correct because: By drawing a tangent to the curve and finding out the gradient oof the curve using two sets of points on the tangent line you can find the slope of the curve. Options A,B,D incorrect because: These options aren’t for finding the slope of the curve.

QUESTION: The total number of transition elements are?
A. 48
B. 38
C. 58
D. 28
EXPLANATION
According to the federal board book, there are 30 d-block transition elements and 28 f-block transition elements, which gives a total of 58.

QUESTION: The geometry of butane is:
A. Octahedral
B. Tetrahedral
C. Trigonal planar
D. Square planar
EXPLANATION
Option B is correct because: The geometry of the molecule is tetrahedral with all the carbon atoms being sp³ and having bonds of 109° of angle. Options A,C,D are incorrect because:

QUESTION: Ethane and hexane both are nonpolar molecules, but ethane has lower Boiling point than Hexane due to?
A. Strong London forces in ethane due to smaller size.
B. Weak London forces in hexane due to larger size.
C. Strong London forces in hexane, due smaller size.
D. Strong london forces in hexane due to larger size.
EXPLANATION
Option D is correct because: The forces in hexane will be stronger than those in ethane because hexane molecules are larger and therefore capable of more extensive London Dispersion Forces between each other than the molecules of ethane. For this reason, hexane has a higher boiling point than ethane. Option A is incorrect because: Smaller size will have less London forces. Option B is incorrect because: Larger size will have greater London forces. Option C is incorrect because: Hexane has a larger size than ethane.

QUESTION: AB4 type with no lone pair shows geometry.
A. Tetrahedral
B. Trigonal
C. Bent
D. Linear
EXPLANATION
Option A is correct because:

QUESTION: Heat is the energy that flows across the?
A. Surroundings
B. Boundaries of the system
C. Only within the system
D. All of these
EXPLANATION
Option B is correct because: Heat is defined as the quantity of energy that flows across the boundary of a system during a change in its state due to the difference in temperature between the system and the surroundings. Options A,C,D are incorrect because: They are incorrect according to the given definition.

QUESTION: Organic compounds are soluble in
A. Polar solvents
B. Water
C. Ammonium cyanate
D. Non-polar solvents
EXPLANATION
Option D is correct because: Because they are very non-polar molecules, with only carbon-carbon and carbon-hydrogen bonds. They are able to bond to themselves very well through nonpolar van der Waals interactions. Option A is incorrect because: They are not able to form significant attractive interactions with very polar solvent molecules. Option B is incorrect because: Water is very polar. Option C is incorrect because: This compound is inorganic.

QUESTION: In Ion electron method, while balancing oxygen and Hydrogen atoms ______.
A. First balance Hydrogen
B. First balance Oxygen
C. Balance both at the same time
D. Order doesnt matter
EXPLANATION
Option B is correct because:

QUESTION: Freezing point of acetic acid;
A. 16.6⁰C
B. 18⁰C
C. -20⁰C
D. 10⁰C
EXPLANATION
Option A is correct because: Acetic acid freezing point is 16.6 degrees celsius. Options B,C,D are incorrect because: Wrong values.

QUESTION: Kinetic molecular theory was proposed by
A. Berzelius
B. Boltzmann
C. Bernoulli
D. Maxwell
EXPLANATION
Option C is correct because: In order to illustrate the behaviour of gases quantitatively, Bernoulli (1738) put forward kinetic molecular theory of gases.

QUESTION: An orbital can accommodate at the most _________ electrons.
A. 2
B. 14
C. 1
D. 6
EXPLANATION
Option A is correct because: Each orbital can hold only two electrons. Electrons that occur together in an orbital are called an electron pair. Options B,C,D are incorrect because: These values are wrong.

QUESTION: A constant force of 10N is applied in horizontal direction and distance travelled in the direction of force is 2m,then work done is ____.
A. 50J
B. 20J
C. 22J
D. 10J
EXPLANATION
Option B is correct because: W.D = F x D W.D = 10 x 2 = 20 J

QUESTION: A strong magnetic field is applied on a stationary electron, then the electron ____.
A. Moves in the direction of the field.
B. Moves perpendicular to the direction of the field.
C. Moves opposite to the direction of the field.
D. Remains stationary
EXPLANATION
Option D is correct because: Magnetic force only acts on moving charges and since the electron is stationary no change will take place. Options A,B,C are incorrect because: Magnetic force will not be applied to a stationary charge.

QUESTION: The efficiency of diesel engine is ___.
A. 10% to 20%
B. 20% to 35%
C. 35% to 40%
D. 40% to 50%
EXPLANATION
Option C is correct because: Diesel engines have a high efficiency (35% to 45%) in power generation. Options A,B,D are incorrect because: Wrong values.

QUESTION: What is the S.I. unit of radioactivity?
A. Curie
B. Rutherford
C. Becquerel
D. All of these
EXPLANATION
Option C is correct because: The SI unit of radioactivity is becquerel (Bq). Options A,B,D are incorrect because: These are not SI units of radioactivity.

QUESTION: Which light has more velocity ___.
A. He-Ne laser
B. White
C. Yellow
D. All are equal
EXPLANATION
Option D is correct because: Light, no matter how high-or-low in energy, always moves at the speed of light, so long as its traveling through the vacuum of empty space. Speed of light has the same value of 299,792,458 m/s at all times and all locations in the Universe. Options A,B,C are incorrect because: In vacuum all light travels at the same velocity.

QUESTION: If number of loops are increased than according to Faraday law ____ will increase.
A. Voltage
B. Electric field
C. Magnetic field
D. All of these
EXPLANATION
Option D is correct because: One way to increase or decrease the strength of the magnetic field is to change the number of loops in the coil. The more loops you add, the stronger the field will become. The faster the magnetic field changes, the greater will be the voltage in the circuit. We can increase the voltage by increasing the number of loops in the circuit. Options A,B,C are incorrect because: All of these increase with increase in number of loops.

QUESTION: Which of the following is a type of rectifier?
A. Half wave
B. Full wave
C. Bridge
D. All of the above
EXPLANATION
Option D is correct. Options A,B,C are incorrect because: These are all types of rectifiers.

QUESTION: The direction of the restoring force is always towards ____.
A. Right hand
B. Upwards
C. Rest or mean position
D. Extreme position
EXPLANATION
Option C is correct because: The restoring force is a force which acts to bring a body to its equilibrium position. The restoring force is a function only of position of the mass or particle, and it is always directed back toward the equilibrium position of the system. Options A,B,D are incorrect because: These are not mean positions so restoring force does not act towards them.

QUESTION: A wire of uniform area of cross-section A and length L is cut into two equal parts, the resistivity of each part _____.
A. Doubles
B. Halves
C. Reamins the same
D. Increases three times
EXPLANATION
Option C is correct because: Resistivity depends on the temperature of the material. At a constant temperature, we can assume the resistivity is a constant. Options A,B,D are incorrect because: Resistivity only depends on temperature and does not depend on length or area of cross section.

QUESTION: A star moving away from earth shows ____.
A. Green shift
B. Red shift
C. Blue shift
D. None of these
EXPLANATION
Option B is correct because: When an object moves away from us, the light is shifted to the red end of the spectrum, as its wavelengths get longer. Option C is incorrect because: If an object moves closer, the light moves to the blue end of the spectrum as its wavelengths get shorter. Options A and D are incorrect because: These options don’t fit the question.

QUESTION: Two objects, with different sizes, masses, and temperatures, are placed in thermal contact. In which direction does the energy travel?
A. Energy travels from the larger object to the smaller object
B. Energy travels from the object with more mass to the one with less mass
C. Energy travels from the object at higher temperature to the object at lower temperature
D. Energy does not travel
EXPLANATION
Option C is correct because: If two objects at different temperatures are brought in contact with each other, energy is transferred from the hotter object (that is, the object with the greater temperature) to the colder (lower temperature) object, until both objects are at the same temperature. Options A,B,D are incorrect because: Thermal energy has to do with temperature not with mass or size.

QUESTION: Which two or more of the following actions would increase the energy stored in a parallel plate capacitor when a constant potential difference is applied across the plates?
A. Decreasing the area of the plates, Decreasing the separation between the plates
B. Decreasing the area of the plates, Increasing the separation between the plates Inserting a dielectric between the plates
C. Increasing the area of the plates, Decreasing the separation between the plates Inserting a dielectric between the plates
D. Increasing the area of the plates, Increasing the separation between the plates
EXPLANATION
Option C is correct because: We can rewrite the energy stored in the capacitor as Here the potential difference is kept constant, so the energy depends only on the dielectric constant of the medium, the area and on the distance between the plates. In particular: - The energy is directly proportional to the area, so as the area increases, the energy will increase - The energy is inversely proportional to the distance, so as the distance decreases, the energy will increase - The energy increases if the value of k increases (that is, if a dielectric is put between the plates) Options A,B,D are incorrect because: These would not increase the energy of the plate according to the equation shown above

QUESTION: Unit of relative permeability is ____.
A. Henry
B. Henry/m
C. Dimensionless
D. Henry/sq.m
EXPLANATION
Option C is correct because: Relative permeability is the ratio of permeability of the material to the permeability of free space. Since it is a ratio, it does not have any units. Options A,B,D are incorrect because: Relative permeability has no units.

QUESTION: In microwave ovens ____ is used to heat the food
A. X-rays
B. Beta rays
C. Gamma rays
D. Electromagnetic rays
EXPLANATION
Option D is correct because: Microwave ovens use electromagnetic radiation to heat food. The non-ionizing radiation used by a microwave does not make the food radioactive. Microwaves are only produced when the oven is operating. The microwaves produced inside the oven are absorbed by food and produce the heat that cooks the food. Options A,B,C are incorrect because: These could cause the food to become radioactive.

QUESTION: In case of harmonic oscillator total energy remains ____.
A. Variable
B. Infinity
C. Constant
D. Zero
EXPLANATION
Option C is correct because: The total energy of the oscillator remains constant, but the energy oscillates between kinetic energy and potential energy. Options A,B,D are incorrect because: The total energy does not vary it changes between kinetic and potential energy.

QUESTION: Projectile when launched at 90 degree with respect to horizontal then its trajectory is ____.
A. Parabolic
B. Periodic
C. Hyperbolic trajectory
D. Linear
EXPLANATION
Option D is correct because: The projectile only covers vertical distance in this case hence it will have a linear trajectory. Options A,B,C are incorrect because: Different trajectories would be possible if the projectile was launched at an angle.

QUESTION: An arc of length equal to the circumference of a circle subtends an angle?
A. π radian
B. 2π radian
C. π/2 radian
D. 4π radian
EXPLANATION
Option B is correct because: If r be the radius of the circle, then circumference of the circle = 2πr Also we know that: 1 radian is the measure of an angle subtended at the centre of a circle of radius r by an arc of length r. i.e. the angle subtended at the centre by an arc of length r = 1 radian Angle subtended at the centre by an arc of unit length = 1/r radian The angle subtended at the centre by an arc of length 2πr = 1/r x 2πr = 2π radians. Thus, the angle subtended at the centre of the circle by the circumference = 2π. Options A,C,D are incorrect because: The values are wrong

QUESTION: A variable force F = x is applied what will be the work done in moving the particle from X= 0 to 1
A. 2 J
B. 1 J
C. 0.5 J
D. 5 J
EXPLANATION
Correct Option C This option is correct because we know from the formula of work done by variable force W=¹₀∫fd cos 0 =∫¹₀ xdx =½ W =0.5 joule

QUESTION: When a monochromatic light travels from glass into air, then ____.
A. Its frequency and wavelength both stays same
B. Its frequency stays same but wavelength increases
C. Its frequency increases but wavelength stays same
D. Its frequency decreases and wavelength increases
EXPLANATION
Option B is correct because: When waves travel from one medium to another the frequency never changes. As waves travel into the less dense medium, they speed up and wavelength increases. Options A,C,D are incorrect because: Frequency never changes and the wavelength increases in less dense mediums

QUESTION: If 1.002 x 10⁶J of thermal energy is required to melt some ice at its melting point, what is the mass of ice that melts? (Specific latent heat of fusion of ice is 334 J/g)
A. 1 kg
B. 2 kg
C. 3 kg
D. 4 kg
EXPLANATION
Option C is correct because: Q = mLf 1.002 x 10⁶ = m x 334 m= 3000g = 3kg

QUESTION: 1 microvolt is ___.
A. 1 x 10^-3 V
B. 1 x 10^-4 V
C. 1 x 10^-5 V
D. 1 x 10^-6 V
EXPLANATION
Option D is correct because: The SI prefix ‘Micro’ represents a factor of 10-6 and is an exponential notation. Volt is the SI derived unit of the electric potential difference mostly referred to as voltage.

QUESTION: When the nucleus of an unstable atom emits only gamma radiation, the nucleus must ____.
A. Gain energy
B. Lose energy
C. Lose protons
D. Gain protons
EXPLANATION
Option B is correct because: To become more stable, the nuclei undergo radioactive decay. In this process, the nuclei give off energy because gamma rays are a form of energy. Options A,C,D are incorrect because: There is no gain of energy in radioactive decay as particles or gamma rays are given off. In this particular question gamma rays are given off that does not affect the atomic number

QUESTION: Sl unit of magnetic induction is ___.
A. Weber
B. Gauss
C. Tesla
D. Maxwell
EXPLANATION
Option C is correct because: Tesla is the SI unit for magnetic induction Options A,B,D are incorrect because: Wrong SI units

QUESTION: When path difference between two waves are integral multiple of wavelength, the resultant effect is called ___.
A. Destructive interference
B. Constructive interference
C. Beats
D. Diffraction
EXPLANATION
Option B is correct because: Constructive interference occurs whenever the difference in paths from the two slits to a point on the screen equals an integral number of wavelengths (0, λ, 2λ,…). This path difference guarantees that crests from the two waves arrive simultaneously. Options A,C,D are incorrect because: These don’t fit the question

QUESTION: Ripple factor of half wave rectifier is ____.
A. 1.21
B. 0.8
C. 0.6
D. 0.4
EXPLANATION
Option A is correct because: The ripple factor of the half wave rectifier is equal to 1.21 (i.e. γ = 1.21). Options B,C,D are incorrect because: Wrong values.

QUESTION: Ozone reflects ____ radiation from sun back into space.
A. IR
B. UV
C. Alpha
D. All of these
EXPLANATION
Option B is correct because: The ozone layer absorbs bits of radiation hitting Earth from the sun. The ozone layer absorbs about 98 percent of this devastating UV light. Options A,C,D are incorrect because: Ozone does not absorb and reflect these radiations

QUESTION: The force between two charges Q and q, separated by a distance d is F. What will be the force between them when distance between them is d/2?
A. 4F
B. 2F
C. F
D. F/2
EXPLANATION
Option A is correct because: The force between the two charges is directly proportional to the product of the charges and inversely proportional to the square of the distance between them. Hence, if distance between charges is halved (charges remaining kept constant), the force between the two charges is quadrupled. Options B,C,D are incorrect because: Wrong values

QUESTION: The convection process transfer heat faster than radiation.
A. It depends on condition
B. Not always
C. True
D. False
EXPLANATION
Option D is correct because: Radiation is the fastest mode of Heat Transfer because it travels from emitting body to receiver body in the form of Electromagnetic waves. Electromagnetic waves travel with the speed of light. Example: we receive energy from sun in the form of radiations. Options A,B,C are incorrect because: Radiation is the fastest way of transferring heat.

QUESTION: When heat is given to isobaric process then ____.
A. Work is done by the gas
B. Internal energy of gas increases
C. Both a and b
D. None of them
EXPLANATION
Option C is correct because: When heat is supplied at constant pressure, a part of it goes in the expansion of gas and remaining part is used to increase the temperature of the gas which in turn increases the internal energy. Options A,B,D are incorrect because: Both A and B are correct for this question

QUESTION: A 4kg eagle picks up a 75g snake and raises it 2.5 m from the ground to a branch. What is the work done to raise the birds own centre of mass to the branch? (Assume g = 10 m/s^2)
A. 100J
B. 1.875J
C. 18.75J
D. 187.5J
EXPLANATION
Option A is correct because: Given info : A 4 kg eagle picks up a 75 g snake and raises it 2.5 m from the ground to a branch. To find : the work done to raise the birds own centre of mass to the branch is.. solution : work done by the eagle to pick up the snake to the branch = change in potential energy of the bird. = mgh₂ - mgh₁ h₁ = height of eagle when it picks up the snake = 0 h₂ = height of eagle when it reaches to the branch = 2.5 m m = mass of bird = 4 kg g = acceleration due to gravity = 10 m/s² ∴ work done = 4 kg × 10 m/s² × 2.5 m = 100 Joules.

QUESTION:

1 Watt = ____.

A.

1 VA

EXPLANATION

Option D is correct because:

The volt-ampere is dimensionally equivalent to the watt (in SI units, 1 V⋅A = 1 W).

Options A,B,C are incorrect because: Wrong dimensions for watt

QUESTION: Half wave rectifier passes only ____.
A. Lower half cycle
B. Upper half cycle
C. Both cycles
D. None of them
EXPLANATION
Option B is correct because: A half-wave rectifier removes the negative half cycle of an AC input and allows only the positive cycles to pass creating a DC flow. Options A, C, and D are incorrect because the negative half cycle gets eliminated.

QUESTION: Which of the following is not unit of power?
A. Horse power
B. Kilowatt
C. kWh
D. Nm/s
EXPLANATION
Option C is correct because: A kilowatt is a measure of power and a kilowatt-hour is a measure of energy. Options A,B,D are incorrect because: These are all units of power

QUESTION: UV radiation is formed by bombarding gas molecules with ____.
A. Electrons
B. Protons
C. Alpha rays
D. Any of these
EXPLANATION
Option A is correct because: Gas molecules after getting bombarded with electrons get ionized and release photons in the UV light region of the EM spectrum. Options B,C,D are incorrect because: These particles do not cause ionization

QUESTION: Radiation can cause ____.
A. Burning
B. Cancer
C. Flu
D. All of these
EXPLANATION
Option D is correct because: Concentrated exposure to radiation causes painful marks on the skin. Radiation of certain wavelengths, called ionizing radiation, has enough energy to damage DNA and cause cancer. Ionizing radiation includes radon, x-rays, gamma rays, and other forms of high-energy radiation. Radiation sickness can cause flu-like symptoms. Options A,B,C are incorrect because: All the options are correct for this question

QUESTION: The Davisson Germer experiment is used to explain _____.
A. Interference
B. Polarization
C. Diffraction
D. None of these options is correct
EXPLANATION
Option C is correct because: The Davisson and Germer experiment showed that electron beams can undergo diffraction when passed through the atomic crystals. This shows that the wave nature of electrons as waves can exhibit interference and diffraction.

QUESTION: The turns ratio of transformer is 10. It means that ____.
A. I_s=10I_p
B. N_s=N_p/10
C. N_s=10N_p
D. V_s=V_p/10
EXPLANATION
Option C is correct because: Turns ratio=N_s/N_p Therefore N_s/N_p=10 Thus N_s=10N_p

QUESTION:

Electric motor converts ___.

A.

Electric energy to mechanical energy

EXPLANATION

Option A is correct because:

An electric motor is a device used to convert electricity into mechanical energy—opposite to an electric generator. They operate using principles of electromagnetism, which shows that a force is applied when an electric current is present in a magnetic field.

Options B,C,D are incorrect because: These conversions are wrong

QUESTION: A stationary wave is set up in a pipe of length L. If the pipe is open at one end and closed at other, what is the ratio of the fifth harmonic frequency to the first harmonic frequency?
A. 4
B. 6
C. 1/5
D. 5
EXPLANATION
Correct Option D Self explanatory (Fact)

QUESTION: The frequency of a wave is 60 Hz. How long does it take to pass 20 complete waves from a point?
A. 1200 sec
B. 12 sec
C. 3 sec
D. 1/3 sec
EXPLANATION
Option D is correct because: Frequency of 60 Hz means that the number of waves passing in 1 second is 60. This means that the time period is 1/60. Time period is the time taken by one complete wave. To calculate the time taken by 20 complete waves time period will be multiplied by 20. T= 1/60 20 x 1/60 = 1/3

QUESTION: Which one of the following is not present in AC generator?
A. Armature
B. Magnet
C. Slip rings
D. Commutator
EXPLANATION
Option D is correct because: The various parts of an AC generator are: Field Armature Prime Mover Rotor Stator Slip Rings

QUESTION: A car of mass 2000 kg moving in a circular path of radius 10 m at a constant speed of 30m/sec. Find the centripetal force required for this purpose.
A. 1800N
B. 18N
C. 180kN
D. 18kN
EXPLANATION
Option C is correct because: F=mv^2/r F=2000 x 30^2/ 10 F= 180,000 = 180kN

QUESTION: 100 W heater is used to melt 50 g of ice at OC. How long should the heater be switched on? (Specific latent heat of fusion of ice is 334 J/g)
A. 28 min
B. 16.7 min
C. 2.8 min
D. 167 min
EXPLANATION
Option C is correct because: mΔH_f=Pt t= 50x334/100 t=167s 167/60=2.8 mins

QUESTION: Resistivity of a wire is ___ ohm-m if 0.75 A current flows through it by applying 1.5 V potential difference. (Take length and cross section as 5m and 2.5 x 10^-7 m²)
A. 1x 10^-7
B. 2.63 x 10^-8
C. 19 x 10^-8
D. 7.85 x 10^-8
EXPLANATION
Option A is correct because: V = IR 1.5=0.75xR R= 2 ohms ρ= RA/L ρ= 2 x 2.5 x 10^-7 / 5 ρ = 1 x 10^-7

QUESTION: The two points of a medium are separated through a distance of 10 cm. What is the phase angle between these two points if the wavelength of the wave is 0.1m?
A. π
B. 2π
C. 3π
D. 3π/4
EXPLANATION
Correct option :B As distance between two point is 10cm which is equal to 0.1m The wavelength is given as 0.1m As we know from the formula of phase angle Phase angle = 2π X ∆distance /wavelength Phase angle =2π X 0.1m/0.1m Canceling 0.1 with 0.1 Phase angle = 2π

QUESTION: Time constant is defined as the time required by the capacitor ____.
A. To deposit 63% of the equilibrium charge
B. To deposit 36% of the equilibrium charge
C. To deposit 63 times of the equilibrium charge
D. To deposit 36 times of the equilibrium charge
EXPLANATION
Option A is correct because: The time constant of a series RC (resistor/capacitor) circuit is a time interval that equals the product of the resistance in ohms and the capacitance in farad and is symbolized by the greek letter tau (τ). The time in the formula is required to charge to 63% of the voltage of the source. Options B,C,D are incorrect because: Values are wrong or not in percentage

QUESTION: A particle of mass 10 kg is moving with velocity 10 (x)^1/2, here x is displacement. The work done by net force during the displacement of particle from x=4 to x=9
A. 1250J
B. 1000J
C. #500J
D. 2500J
EXPLANATION
Option D is correct because

QUESTION: Magnetic field lines have a property that lines are ____.
A. Not intersecting
B. Intersect near south pole
EXPLANATION
Option A is correct because: The magnetic field lines never intersect each other because if two or more lines intersect each other then it means that at that point of intersection, the magnetic field has two directions at the same point. This is not possible for a magnetic field to point in more than one direction at the same point. Options B,C,D are incorrect because: Magnetic field lines do not intersect

QUESTION: Power transfer from primary to secondary is through flux linkage, so the primary and secondary coils should be wound in such a way that flux coupling between them is ____.
A. Min
B. Constant
C. Zero
D. Max
EXPLANATION
Option D is correct because: In an ideal transformer, the coefficient of coupling between primary and secondary coils should be 1 (max). That is, they should be perfectly magnetically coupled.

QUESTION: A full wave rectifier is operating from 50 Hz mains. Fundamental frequency of ripple will be ____.
A. 100 Hz
B. 25 Hz
C. 50 Hz
D. 200 Hz
EXPLANATION
Option A is correct because: In a full wave rectifier, we get the output for the positive and negative cycle of input a.c. Hence the frequency of the ripple of the output is twice than that of input a.c. i.e. 100Hz Options B,C,D are incorrect because: Wrong values

QUESTION: The electron is purely a ___ when free.
A. Particle nature
B. Wave nature
C. Dual nature
D. It transforms to photon
EXPLANATION
Option C is correct because: For the particle or wave nature to be seen experiments have to be done for them specifically but without the experiments electrons exist in dual nature. Options A,B are incorrect because: Specific experiments have to be done to exhibit these natures Option D is incorrect because: Electrons don’t transform into photons

QUESTION: Lamination of the transformer core is made of
EXPLANATION
Eddy currents passing through the core of a transformer due to the induced voltages can cause heat loss. This heat loss is reduced significantly by silicon steel lamination of the core.

QUESTION: The attraction capacity of electromagnet will increase if the
A. Core length increases
EXPLANATION
Flux density represents the number of magnetic field lines passing through a cross section. More field lines passing means a greater magnetic field will be produced. A stronger magnetic capacity therefore means that more magnetic field lines are passing through a surface.

QUESTION:

During adiabatic expansion internal energy decreases by 2J, then work done in this process is

EXPLANATION

In an adiabatic process, the net of a system remains 0. The equation for heat is given by; Q = ΔU + W

As the heat energy is 0; 0 = ΔU + W

Therefore, W = -ΔU

There is a 2J decrease in the internal heat U, which can be written as -2J, with the negative sign representing the decrease. Thus, by the equation, work done is +2J.

QUESTION: The radiations all around us are called __ radiations.
EXPLANATION
Humans come into contact with radiation on a daily basis. These radiations are both natural, such as the rays from the sun, and artificial, such as those from our TV screens or kitchen stoves. This radiation that we experience on a daily basis is known as background radiation.

QUESTION: The proton and antiproton collision will result
EXPLANATION
When a proton and antiproton collide with each other at relatively low speeds and energies, annihilation ensues, which is the process of a particle and its antiparticle colliding to produce photons.

QUESTION: Dependent causes/ Independent causes: Statement: There is a sharp decline in the production of oilseeds this year. The government has decided to increase the import quantum of edible oil.
A. Statement I is the cause and statement II is its effect
B. Statement II is the cause and statement I is its effect
C. Both the statements I and II are independent causes
D. Both the statements I and II are effects of some common cause
EXPLANATION
Due to the decline, oil supply was reduced and the only way to make up for the shortage of oil was to import it.

QUESTION: Essential parts: What should come next to it book
A. Pages
B. Learning
C. Pictures
D. eraser
EXPLANATION
The necessary part of a book is its pages; there is no book without pages. Not all books are writing books hence they don’t need erasers, and not all books have pictures Learning may or may not take place with a book.

QUESTION: What is the common vowel in Apple and Banana?
A. E
B. P
C. A
D. M
EXPLANATION
Apple has two vowels A and E however Banana only has one vowel which is A. So the common vowel is A.

QUESTION: Statements and Conclusions: Statements: Some papers are pens. Angle is a paper. Conclusions I. Angle is not a pen. II. Angle is a pen
A. Only conclusion II follows
B. Either I or II follows
C. Neither I nor II follows
D. Both I and II follows
EXPLANATION
From the information given we know that angle is a paper. However, the first statement says that “some” papers are pens which implies that the papers(which is the same as the angle) may or may not be a pen hence both statements are incorrect.

QUESTION: Statements and Actions: Statement A smoker has left smoking suddenly. a. He will feel restlessness and anxiety b. He will start gaining weight
A. Both of them follows
B. None of them follows
C. Only b follows
D. Only a follows
EXPLANATION
Withdrawal symptoms of smoking include restlessness and anxiety due to psychological and physical dependence. Quitting smoking has no effect on weight gain or loss.

QUESTION: Dependent causes/ Independent causes: Statement: The farmers have decided against selling their Kharif crops to government agencies. The government has reduced the procurement price of Kharif crops starting from last month to the next six months.
A. Statement I is the cause and statement II is its effect
B. Statement II is the cause and statement I is its effect
C. Both the statements I and II are independent causes
D. Both the statements I and II are effects of independent causes
EXPLANATION
Since the government has reduced the procurement price of Kharif crops starting from the last months to the next six months, therefore, the farmers have decided against selling their Kharif crops to the Government agencies.

QUESTION: Verbal Classification: Who won the Wimbledon Mens Singles Tennis Title?
A. Roger Federer
B. Novak Djokovic
C. Rafael Nadal
D. Both A and B
EXPLANATION
Novak Djokovic wins Wimbledon mens singles title, equals Federer and Nadals all-time Grand Slam record.

QUESTION: Dependent causes/ Independent causes: Statement: The state bank of Pakistan has recently put restrictions on few small banks in the country. The small banks in the private and co-operative sector in Pakistan are not in a position to withstand the competitions of the bigger in the public sector.
A. Statement I is the cause and statement II is its effect
B. Statement II is the cause and statement I is its effect
C. Both the statements I and II are independent causes
D. Both the statements I and II are effects of independent causes
EXPLANATION
As, the small banks in the private and co-operation sector in Pakistan are not in a position to withstand the competition of the bigger banks in the public sector, therefore, the Reserve Bank of Pakistan has recently put restrictions on a few small banks in the country.

QUESTION: Dependent causes/ Independent causes: Statement: Most of the steel-producing companies in the country have made a considerable profit during the last financial year. Many Asian countries have been importing huge quantities of steel from Pakistan.
A. Statement I is the cause and statement II is its effect
B. Statement II is the cause and statement I is its effect
C. Both statements I and II are independent causes
D. Both statements I and II are effects of independent causes
EXPLANATION
The increase in demand of steel from other countries is bound to enhance business and hence the profitability of steel companies in Pakistan.

QUESTION: Complete the series: Quote and Poet has ____ number of same letters.
A. 5
B. 4
C. 3
D. 2
EXPLANATION
“o” “t” and “e” are the only same letters in quote and poet.

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PMC Paid Practice Tests Series 2021 With Explanation - Test 33

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