PMC Paid Practice Tests Series 2021 With Explanation - Test 34

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: She thanked me for what I _____.
A. Have done
B. Has done
C. Have been done
D. Did
EXPLANATION
The given sentence is in the past tense, as is indicated by the verb “thanked”, hence the other verb will also be in the past tense.

QUESTION: This book has won _____ Booker prize.
A. A
B. An
C. The
D. No article is required
EXPLANATION
“Booker” is a proper and specific noun, hence it will be conjugated with “the”.

QUESTION: Excuse me, could you _____ me the way to the town hall?
A. Let
B. Put
C. Talk
D. Tell
EXPLANATION
This question tests vocabulary. The definition of ‘tell’ involves delivering information to someone.

QUESTION: The earth ____ around the sun.
A. Move
B. Moves
C. Moved
D. Has been moving
EXPLANATION
As “Earth” is a third-person singular word, “-s” or “-es” must be added to the verb that follows it.

QUESTION: Where were you _____ at that time?
A. Going
B. Goes
C. Went
D. Gone
EXPLANATION
The given sentence is in the past continuous tense, as indicated by the word “were”. The past continuous tense is formed by combining was/were with the [verb]+ing.

QUESTION: Much _____ been said in the news reports.
A. Were
B. Have
C. Has
D. Was
EXPLANATION
The word “been” indicates present perfect continuous tense, which is formed by conjugating “has been” with the past participle of the verb i.e. “has been” + “said”.

QUESTION: I work as ____ only English teacher at this school.
A. A
B. An
C. tHE
D. No article is required
EXPLANATION
The “English teacher” in the given sentence is a proper noun and hence will be conjugated with “the”.

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.
D. I like to cook. I like to make cake, bread, and pie.
EXPLANATION
Option D displays correct use of punctuation to separate clauses and to indicate declarative sentences.

QUESTION: No news ____ good news.
A. Is
B. Are
C. Was
D. Were
EXPLANATION
“News” is a singular noun and hence will be referred to with the singular form of the verb (“is”).

QUESTION: My father ________ us popcorn and orange juice.
A. Buy
B. Will buy
C. Bought
D. Have bought
EXPLANATION
The simple past tense form of the verb “buy” is “bought”.

QUESTION: Choose the correct spelling of the word.
A. Goas
B. Gose
C. Goes
D. Gois
EXPLANATION
This question tests vocabulary. The correct spelling is option C, “goes”.

QUESTION: What is the tense of this question? What will you do when this course finishes?
A. Present
B. Past
C. Future
D. None of these options are correct
EXPLANATION
The given question is in the future tense as indicated by the words “what will you do”.

QUESTION: What type of sentence is this? She said that she was happy.
A. Complex
B. Simple
C. Compound
D. None of these options are correct
EXPLANATION
The given sentence is a simple sentence as it contains only one independent clause.

QUESTION: The excuse he gave was extremely ____.
A. Delicate
B. Flimsy
C. Slight
D. Thin
EXPLANATION
This question tests vocabulary. The definition of “flimsy” involves something being unsuitable or insubstantial.

QUESTION: Asif tried to stop the car but the ____ did not work and he hit a pole.
A. Brakes
B. Cross roads
C. Tires
D. Controls
EXPLANATION
This question tests vocabulary. “Brakes” are the part of a vehicle that enables it to decelerate and stop.

QUESTION: Choose the correct spelling of the word:
A. Except
B. Excapt
C. Excipt
D. Ecsept
EXPLANATION
This question tests vocabulary. The correct spelling is option A, “except”.

QUESTION: Everything ____ fine when its done correctly.
A. Work
B. Worked
C. Will work
D. Works
EXPLANATION
The given sentence is in the present tense as indicated by the contraction “it’s”. Hence, the verb will also be in the present tense i.e. “works”.

QUESTION: Choose the correct sentence:
EXPLANATION
Option A displays correct use of punctuation to separate clauses and spoken dialogue, and the correct use of punctuation to indicate contractions.

QUESTION: Choose the correct spelling of the word:
A. Comitte
B. Commite
C. Committee
D. Comittee
EXPLANATION
This question tests vocabulary. The correct spelling is option C, “committee”.

QUESTION: She _________ the floor when her cousin came in. She scolded him angrily because he made the floor dirty with his muddy shoes.
A. Mopped
B. Was mopping
C. Mops
D. Is mopping
EXPLANATION
The given scenario is in the past tense, as indicated by the verb “scolded”, hence the missing verb must also be in the past tense i.e. “was mopping”.

QUESTION: The complete mature and infectious particle is known as:
A. Capsid
B. Virion
C. Bacteriophage
D. Nucleus
EXPLANATION
Option B is correct since the virion is the complete viral particle consisting of RNA or DNA surrounded by the protein shell, constituting the infective form of a virus. Option A is incorrect since capsid is the protein shell of a virus. Option C is incorrect since bacteriophage is a virus that infects and replicates within bacteria. Option D is incorrect since the nucleus is a membrane-bound organelle.

QUESTION: Which factors affect the female reproductive cycle?
A. Malnourishment
B. Emotional stress
C. Options A and B are correct
D. None of these options are correct
EXPLANATION
Option C is correct since both malnourishment and emotional stress affect the menstrual cycle as stress affects the part of the brain responsible for producing hormones. Option A and Option B are incorrect since the best option would be Option C to choose.

QUESTION: Which reaction is catalyzed by the enzyme RuBisCO?
A. Carboxylation of ribulose bisphosphate (RuBP)
B. Conversion of triose phosphate (TP) to ribulose phosphate (RuP)
C. Oxidation of glycerate-3-phosphate (GP)
EXPLANATION
Option A is correct since the enzyme RuBisCo catalyzes the addition of gaseous carbon dioxide to RuBP. Option B is incorrect since the triose phosphate is used to regenerate ribulose phosphate and it’s not catalyzed by enzyme rubisco. Option C is incorrect since oxidation of glycerate-3-phosphate is catalyzed by glyceraldehyde-3-phosphate dehydrogenase. Option D is incorrect since a reduction of glycerate-3-phosphate is catalyzed by glyceraldehyde phosphate dehydrogenase.

QUESTION: If the gene expresses itself, then the penetrance is:
A. 40%
B. 50%
C. 75%
D. 1
EXPLANATION
Option D is correct since when the gene expresses itself the penetrance would be completely equal to 1. Options A, B, and C are incorrect since the percentages of 40%,50%, and 75% are showing incomplete penetration.

QUESTION: The organisms able to use sunlight directly as a source of energy are:
A. Plants
B. Animals
C. Fungi
D. Omnivores
EXPLANATION
Option A is correct since plants use sunlight as a source of energy to generate chemical energy in the form of sugars. Options B and D are incorrect since animals and omnivores have relatively advanced anatomy and physiology, they cant use sunlight as a direct source of energy. Option C is incorrect since fungi unlike plants are incapable of doing photosynthesis so they dont use sunlight.

QUESTION: Which scientist came up with the term cell?
A. Schwann
B. Scheilden
C. Robert Hooke
D. Both Options A and B are correct
EXPLANATION
The cell was discovered by Robert Hooke in 1665, in a Cork piece, in which he saw small compartments. He named them as cells because they resembled small rooms cellulae (latin) in which Monks used to live. Scheilden and Schwann coined the cell theory AFTER the cell had been discovered and named.

QUESTION: Carapace is present in which class of arthropods?
A. Arachnids
B. Insects
C. Crustaceans
D. All of these options are correct
EXPLANATION
Carapace is a hard shell found at the back of crustaceans such as crab (and turtle in chordates). It is found neither in insects nor in arachnids.

QUESTION: What is the method of asexual reproduction?
A. Sporulation
B. Fission
C. Apomixis
D. All of these options are correct
EXPLANATION
Option D is correct since sporulation, fission, and apomixis all are the methods of asexual reproduction.

QUESTION: Two species can avoid competition and can make better use of the environments resources by occupying different:
A. Adaptation
B. Polymorphism
C. Niches
D. Specialisation
EXPLANATION
A niche is the exact position or location, so if two species occupy different niches, they will be having separate reservoirs of environmental resources. Hence, there will be no competition to survive and avail the resources. However, if they occupy different polymorphism, adaptation, or specialization (options A, C, and D) they will still be sharing the resources which will create competition.

QUESTION: The part of the chloroplast where carbon dioxide is fixed to manufacture sugar is:
A. Stroma
B. Grana
C. Thylakoid
D. Outer membrane
EXPLANATION
Carbon dioxide fixation is actually dark reaction with takes place in stroma of the chloroplast. Grana are stacks of thylakoids and thylakoids are the sites of light reaction.

QUESTION: Which of these is not involved in respiration?
A. Lung
B. Trachea
C. Bronchi
D. Glucagon
EXPLANATION
Option C is correct since glucagon does not involve respiration. It is rather involved in blood glucose level regulation. Option A is incorrect since the lungs allow us to breathe, and it involves respiration. Option B is incorrect since the trachea is a path that helps the air to transport in breathing. Option D is incorrect since the bronchi are the passageway that helps to connect to the lungs.

QUESTION: The loss of liquid via the hydathodes is called:
A. Ascent of sap
B. Plasmolysis
C. Imbibition
D. Guttation
EXPLANATION
Option D is correct since guttation is the loss of water droplets from hydathodes. Option A is incorrect since the ascent of sap is the upward movement of water in plants. Option B is incorrect since plasmolysis is a process in which cells lose water as in hypertonic solution. Option C is incorrect since imbibition is a process which takes place when water is being absorbed by a substance.

QUESTION: Which of the following is non-cellular in animals in most cases?
A. Chlorenchyma
B. Mesoderm
C. Sclerenchyma
D. Mesenchyme
EXPLANATION
The mesenchyme may be non-cellular (as in sponges where it is called mesohyl) or may comprise of undifferentiated embryonic cells. The other structures mentioned are in all cases cellular. A chlorenchyma is a photosynthetic parenchyma.

QUESTION: The selection for a trait on one extreme is called which of the following?
A. Natural selection
B. Directional selection
C. Stabilizing selection
D. All of these options are correct
EXPLANATION
Option B is correct since directional selection is the one extreme of the trait distribution that experiences selection against it. Option A is incorrect since natural selection helps an organism survive and reproduce more effectively. Option C is incorrect since stabilizing selection means it stabilizes on a particular nonextreme trait value. Option D is incorrect since Option A and C did not fulfill the requirement of the question.

QUESTION: In mixed inhibition, the allosteric effect affects:
A. Shape of substrate
B. Shape of inhibitor
C. Shape of enzyme
D. None of these options are correct
EXPLANATION
Option C is correct since the shape of the enzyme is affected as it is altered to the active site so that the enzyme can no longer bind to its substrate. Option A is incorrect since the substrate is affected when it is bound by increasing the enzyme affinity. Option B is incorrect since the inhibitors reduce the compatibility of substrate and enzyme Option D is incorrect since the correct option is C.

QUESTION: The shape of grey matter is:
A. Spherical
B. Butterfly
C. Mosquito
D. Rectangular
EXPLANATION
Option B is correct since the center of the cord is shaped like a butterfly. Options A, C, and D are incorrect since we know that the grey matter is butterfly-shaped and not spherical, rectangular, or mosquito shaped.

QUESTION: All of the following about reflex action are true except:
A. It is voluntary
B. It is involuntary
C. It is found in higher animals
D. It helps in protection from hot objects
EXPLANATION
Option A is correct since voluntary actions involve conscious thoughts whereas reflex actions do not involve conscious thoughts. Option B is incorrect since reflex actions are involuntary. Option C is incorrect since reflex actions are found in higher animals. Option D is incorrect since reflex actions help protect extremities from damage.

QUESTION: In cell fractionation, various components of cells including its organelles can be isolated in different layers depending upon:
A. Their physical properties like size and weight
B. Physical properties of the medium like its density
C. Their electrical properties like their charges
D. Both Options A and B are correct
EXPLANATION
In the process of cell fractionation by centrifugation, various components of cells are separated depending upon their physical properties like size, weight, and density. Denser particles tend to sediment/settle faster. Choice of medium according to density also plays a great role. However, since there is no electric field, there is no use for electrical properties and charge.

QUESTION: The second largest phylum of invertebrates is which of the following?
A. Porifera
B. Arthropoda
C. Chordata
D. Mollusca
EXPLANATION
Molluscs are the 2^nd largest phylum of invertebrates after arthropoda. Porterage are the simplest of all invertebrates, and chordates are the third largest phylum.

QUESTION: The communication between the two hemispheres is the function of:
A. Corpus Callosum
B. Hindbrain
C. Cerebellum
D. Cerebrum
EXPLANATION
Option A is correct since the corpus callosum allows the two hemispheres to communicate with each other. Option B is incorrect since the hindbrain coordinates functions that are fundamental to survival. e.g. respiratory rhythm, sleep, etc. Option C is incorrect since the cerebellum is involved in the maintenance of balance and posture. Option D is incorrect since the cerebrum initiates and coordinates movement, regulates temperature, and controls conscious activities.

QUESTION: A Dutch scientist first observed very small creatures in:
A. Vinegar
B. Saliva
C. Rainwater
D. All of these options are correct
EXPLANATION
Small creatures were discovered in rainwater by Antonnie Van Leeuwenhoek. He called them animalcules (small animals in latin).

QUESTION: Which of the following is not part of the female reproductive system?
A. Ovary
B. Vagina
C. Urethra
D. Prostate gland
EXPLANATION
The prostate gland is a part of the male reproductive system. Answer C is also correct because the urethra is a part of the urinary system and not the female reproductive system, but the answer was marked as D in this paper according to the PMC marking scheme.

QUESTION: In a dihybrid cross, what fraction of offsprings is homozygous for both traits?
A. 1/2
B. 1/4
C. 1/8
D. 1/16
EXPLANATION
Option C is correct since there are only two out of 16 offsprings homozygous for both traits: Hence: 2/16=1/8

QUESTION: While bound to the active site, the substrate is converted into which of the following?
A. Complex
B. Substrate of high energy
C. Product of reaction
D. Both Options A and B are correct
EXPLANATION
When a substrate has been bound to the active site, the enzyme cleaves its bonds and it is converted to product. A complex consists of both enzyme and substrate, not just the substrate. An enzyme never converts a substrate to a substrate of higher energy.

QUESTION: The outer portion of the spinal cord is composed of:
A. White matter
B. Gray matter
C. Cell bodies
D. Non-myelinated nerve fibres
EXPLANATION
Option A is correct since the outer portion of the spinal cord consists of white matter because of the fatty substance (myelin) that surrounds the nerve fibers. Option B is incorrect as gray matter is present in the inner portion of the spinal cord in a butterfly shape. Option C is incorrect since cell bodies are present in the dorsal root ganglia. Option D is incorrect since myelinated axons are present in the gray matter.

QUESTION: Water vapors exit and carbon dioxide enters a leaf through:
A. Stomata
B. Grana
C. Porphyrin ring
D. Photons
EXPLANATION
Leaves have tiny pores on their surfaces which are called stomata. Gases and water vapors are exchanged with the atmosphere through them. Grana are the stacks of thylakoids, porphyrin ring is a part of chloroplast which absorbs light, and photons are the packets of energy that, when travel in the form of waves, are called light.

QUESTION: The number of autosomes in the human sperm is:
A. 11
B. 22
C. 44
D. 45
EXPLANATION
A human sperm is a haploid gamete that contains half the number of chromosomes found in somatic cells. Thus, Somatic cells: 46 chromosomes (44 autosomes + 2 sex chromosomes). Gametes: 23 chromosomes (22 autosomes + 1 sex chromosome). 45 chromosomes are found in diploid cells of Turners Syndrome cases.

QUESTION: Flagella must have arisen through the ingestion of:
A. Cyanobacteria
B. Chlamydomonas
C. Paramecium
D. Spirochetes
EXPLANATION
Spirochetes are spiral shaped bacteria that resemble flagella. Evolutionist believe that flagella might have arisen when a eukaryote engulfed a spirochete, and it established itself as flagella in the eukaryote. Engulfing of cyanobacteira is thought to have led to endosymbiotic development of chloroplast. Chlamydomonas itself uses flagella, and paramecium is a eukaryote and does not resemble flagella.

QUESTION: The change in frequency of alleles at a locus that occurs by chance is which of the following?
A. Mutation
B. Selection
C. Non-random mating
D. Genetic drift
EXPLANATION
Option D is correct since genetic drift is a change in allele frequencies in a population from generation to generation that occurs due to chance events. Option A is incorrect since mutation is a change in a DNA sequence. Option B is incorrect since natural selection increases genetic variation whereas genetic drift does not in comparison to natural selection. Option C is incorrect since non-random mating means that mate selection is influenced by phenotypic differences based on underlying genotypic differences.

QUESTION: Hemophilia is a sex-linked recessive disease. A mother that is a carrier of the disease mates a healthy male. Which of the following statements is true?
A. The daughters are just likely to be hemophilic as the sons are
B. 50% of the daughters will have hemophilia
C. None of the children will have hemophilia because the mother is the only carrier
D. 50% of sons will have hemophilia
EXPLANATION
Option D is correct since the male adopts the X link trait from the mother so 50% of the sons will be hemophilic. Option A is incorrect since the daughters cant be hemophilic as they require two X-linked hemophilia traits to be hemophilic. Option B is incorrect since no daughter will be hemophilic as the mother is a carrier and the father is a healthy man. Option C is incorrect since the sons will be hemophilic as they’ll adopt the affected X-linked hemophilia trait from the mother.

QUESTION: If the pH of a solution changes slightly, there is a __________.
A. Change in the ionization of the active site of enzyme
B. Change in the ionization of substrate
C. Retardation or blockage of enzyme activity
D. All of these options are correct
EXPLANATION
Changes in pH implies an increase in either the concentration of Hydrogen ions or Hydroxide ions. These ions would react with the enzyme, causing a deformity to the active site, rendering it incapable of functioning, or they can interact with the substrate, inducing a reaction.

QUESTION: In humans, usually only one ovum is discharged at one time. This phenomenon is called?
A. Ovulation
B. Menstruation
C. Oestrous
D. All of these options are correct
EXPLANATION
Option A is correct since ovulation is the process when the ovum is discharged from the ovary. Option B is incorrect since menstruation is normal vaginal bleeding that occurs as part of a womans monthly cycle. Option C is incorrect since oestrous is the set of recurring physiological changes that are induced by reproductive hormones. Option D is incorrect since all of the options are not correct.

QUESTION: Which of the following best describes the prosthetic group?
A. Loosely bonded non-protein part of an enzyme
B. Cofactor consists of metal ion
C. Covalently bounded non-protein part of an enzyme
D. None of these options are correct
EXPLANATION
Option C is correct since covalently bonded non-protein part of an enzyme describes the prosthetic group perfectly. Option A is incorrect since the prosthetic group involves tightly bounded proteins, not loosely packed. Option B is incorrect since the prosthetic group contains loosely packed metal ions. Option D is incorrect since Option C is correct.

QUESTION: In the passage way of air, the incoming air passes from the pharynx to:
A. Bronchi
B. Bronchioles
C. Windpipe
D. Larynx
EXPLANATION
The passage way of air from nasal cavity to lungs is as follows: Nose ---> pharynx ---> larynx (voice box) ---> trachea (windpipe) ---> bronchi ---> bronchioles ---> alveoli (air sacs)

QUESTION: The proximal part of the oviduct is significant because:
A. Fertilization occurs here
B. Implantation occurs here
C. Placenta is established here
D. None of these options are correct
EXPLANATION
Option A is correct since it is the part where fertilization and early cleavage of the fertilized ovum occur. Option B is incorrect since implantation occurs in the uterine endometrium. Option C is incorrect since the placenta is established in your uterus during pregnancy. Option D is incorrect since Option A is correct.

QUESTION: What does ATP provide during photosynthesis?
A. Mechanical energy
B. Chemical energy
C. Physical energy
D. All of these options are correct
EXPLANATION
Option B is correct since chemical energy is provided for the light dependent reactions. Option A and C are incorrect since mechanical energy and physical energy are not provided by ATP. Option D is incorrect since Option A and B are wrong.

QUESTION: Which of the following is unique to prokarytes?
A. They lack cytoplast
B. They have a cell wall
C. They cannot create proton gradients
D. They can conduct mRNA translation simultaneous to transcription
EXPLANATION
Option D is correct since it is a unique characteristic of prokaryotic cells as not found in any other cell characteristics. Options A, B, and C are incorrect since all the characteristics are ordinary.

QUESTION: During which of the following levels of biological organization can natural selection occur?
A. Gene
B. Individual
C. Group
D. All of these options are correct
EXPLANATION
Genetic variation is possible at all levels mentioned above. Genetic mutations are caused at gene levels. Individual variations are the traits through which individuals differ from one another (e.g. height, eye color, etc), and variations in groups are those variations in which a particular trait is common in a group of individuals, but is not found in the other group.

QUESTION: Some bacteria have resistant organelles called as:
A. Spores
B. Cysts
C. Granules
D. All of these options are correct
EXPLANATION
Option A is correct since spores are considerably more resistant to moist and dry heat than non-sporulating bacteria. Option B is incorrect since cysts are thick-walled structures produced by dormant members of Azotobacter. Option C is incorrect as granules are an important component of metabolism in many organisms spanning the bacterial, eukaryotes, and archaea domains. Option D is incorrect since Options B and C are wrong.

QUESTION: A hydrostatic skeleton is present in:
A. Arthropods
B. Fish
C. Annelids
D. Nematods
EXPLANATION
Option C is correct since Annelids worms have a hydrostatic skeleton or hydroskeleton. Option A is incorrect since Arthropods have an exoskeleton as it provides a large surface area for the attachment of muscles. Option B is incorrect since Fishes also have an exoskeleton, which is the stable outer shell of an organism. Option D is incorrect since Nematodes have a cylindrical body with tapered ends which have no skeleton.

QUESTION: The thick muscular structure which is present below the pair of lungs is called:
A. Pharynx
B. Diaphragm
C. Bronchi
D. None of these options are correct
EXPLANATION
Option B is correct since the diaphragm is present below the lungs, the major muscle of respiration. Option A is incorrect since the pharynx is a part of the throat. Option C is incorrect since bronchi are the large tubes that connect to your trachea. Option D is incorrect since Option B is correct.

QUESTION: What is an example of an oviparous mammal?
A. Penguin
B. Shark
C. Spiny anteater
D. Elephant
EXPLANATION
The only two oviparous (egg laying) mammals are echidnas (spiny anteaters) and duckbill platypus. Elephants are placental mammals, sharks are pisces, and penguins are aves.

QUESTION: The brain is mainly divided into _________ parts.
A. 2
B. 3
C. 4
D. 5
EXPLANATION
The brain is divided into 3 parts: forebrain, midbrain, and hindbrain.

QUESTION: How does pyruvate enter the Krebs cycle after glycolysis?
A. Pyruvic acid
B. Acetyl CoA
C. Carbon dioxide
D. Both Options A and B are correct
EXPLANATION
Option B is correct since acetyl CoA is a molecule that is further converted to oxaloacetate, which enters the citric acid cycle (Krebs cycle). Option A is incorrect since pyruvic acid molecules are converted to a two-carbon molecule attached to Coenzyme A, called acetyl CoA. Option C is incorrect since Carbon Dioxide is released as a waste product of these reactions. Option D is incorrect since Option A is wrong.

QUESTION: Which of the following parts of cell is described as fluid mosaic?
A. Chloroplast
B. Vacuole
C. Cell membrane
D. Endoplasmic reticulum
EXPLANATION
The fluid mosaic model describes the cell membrane as a tapestry of several types of molecules (phospholipids, cholesterols, and proteins) that are constantly moving. This movement helps the cell membrane maintain its role as a barrier between the inside and outside of the cell environment.

QUESTION: What is the approximate diameter of retrovirus?
A. 150 nm
B. 100 nm
C. 200 nm
D. 250 nm
EXPLANATION
Option B is correct since most retroviruses are spherical particles approximately 100 nm in diameter. Options A, C, and D are incorrect since 150 nm, 200 nm and 250 nm would not be suitable for spherical particles.

QUESTION: What is the length of the windpipe?
A. 12 cm
B. 13 cm
C. 15 cm
D. 20 cm
EXPLANATION
The length of the trachea is 11.8 cm to 12 cm.

QUESTION: Which cells secrete pepsinogen?
A. Mucous
B. Parietal
C. Zymogen
D. Oxyntic
EXPLANATION
Option C is correct since zymogen cells are present at the base of the gland which produce the enzyme pepsinogen. Option A is incorrect since mucous cells secrete an alkaline mucus. Options B and D are incorrect since parietal cells are also known as oxyntic cells, they secrete hydrochloric acid (HCl) and intrinsic factor.

QUESTION: The function of the centrosome is:
A. Osmoregulation
B. Secretion
C. Protein synthesis
D. Formation of spindles
EXPLANATION
Centrosomes are made up of 2 centrioles that form mitotic spindles. Osmoregulation is a function of the plasma membrane, secretion is a function of vacuoles and protein synthesis is the function of ribosomes.

QUESTION: The joint that allows movement in two directions is called:
A. Fibrous joint
B. Cartilagenous joint
C. Hinge joint
D. Ball and socket joint
EXPLANATION
Option C is correct since the hinge joint facilitates bending and straightening actions. Option A is incorrect since fibrous joints are also known as fixed or immovable joints as they do not move. Option B is incorrect since cartilaginous movement allows only slight movement. Option D is incorrect since ball and socket joints possess a rounded, ball-like end of one bone fitting into a cuplike socket of another bone.

QUESTION: Which cells produce oogonia in the ovary?
A. Stromal cells
B. Epithelial cells
C. Germ cells
D. Theca cells
EXPLANATION
Option C is correct since germ cells in the ovaries differentiate into oogonia. Option A is incorrect since stromal cells are associated with maturing follicles may acquire endocrine function and secrete estrogens. Option B is incorrect since epithelial cells are a single layer of cells that covers the ovary. Option D is incorrect since theca cells produce androgens in response to luteinizing hormone (LH).

QUESTION: In some cases, the blastomere produces a complete embryo. The cleavage will be:
A. Spiral and determinate
B. Spiral and indeterminate
C. Radial and determinate
D. Radial and indeterminate
EXPLANATION
Option D is correct since the radial cleavage with each cell directly below or above another and intermediate in which cells are separated in early embryonic stages can develop into an entire embryo. Options A and B are incorrect since spiral cleavage occurs such that the resulting daughter cells are not located exactly on top of one another. Option C is incorrect since determinate cleavage is an egg in which each division irreversibly separates portions of the zygote with specific potencies for further development.

QUESTION: Lymph vessels transfer lymph into blood through:
A. Subclavian artery
B. Subclavian vein
C. Iliac artey
D. Iliac vein
EXPLANATION
Option B is correct since the right subclavian vein is present at the base of the neck and transfers the lymph into the blood. Option A is incorrect since subclavian arteries are present just below the clavicles providing blood to the head and neck. Option C is incorrect since the iliac artery is the main artery of the pelvic region, supplying blood to the bones, organs, and muscles. Option D is incorrect since iliac veins are located in the abdomen and they drain deoxygenated blood and return this blood to the heart.

QUESTION: Which of the following is not a true charecteristic of gametocytes?
A. Male gametocytes are called spermatocytes
B. Gametocytes can divide by mitosis into other gametocytes
C. Female gametocytes are called oocytes
D. They are eukaryotic somatic cells
EXPLANATION
Gametocytes are eukaryotic germ cells and not somatic cells. Somatic cells do not undergo meiosis however, the gametocytes can undergo both mitosis and meiosis.

QUESTION: Which statement best describes the Hardy-Weinberg principle?
A. Recessive alleles eventally disappear in large population
B. Expected frequencies of alleles are impossible to predict mathematically
C. Dominant alleles become more prevailent in large populations
D. When there is large population, the inheritance of alleles does not change the allele frequency
EXPLANATION
In population genetics, the Hardy–Weinberg principle states that allele and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences. Also, the larger the population, the less the percentage effect of any drift is seen and the overall frequency remains almost the same. Whereas in small populations, even a small change has a greater impact because it affects a greater proportion of the population.

QUESTION: Which of the following is not a characteristic feature of tapeworm?
A. Each body segment has two sets of male and female reproductive organs
B. The digestive tract develops from endodermal cells of the embryo
C. The body can be cut into two parts, which are mirror images of each other, in one plane only
D. None of the above options are correct
EXPLANATION
Option B is correct since the tapeworm does not have a digestive tract. Instead, they absorb their nutrients from the gut contents of the host directly through their outside surface integument. Option A is incorrect since tapeworms do have two sets of male and female reproductive organs. Option C is incorrect since tapeworms do have bilateral symmetry. Option D is incorrect since Option B is correct.

QUESTION: Which of the statement is not true for compounds like glycoproteins and glycolipids?
A. They are conjugated molecules of carbohydrates
B. Both have a role in extracellular matrix of animal and bacterial cell wall
C. They are components of biological membranes
D. Both are produced and seceted by the endoplasmic reticulum
EXPLANATION
Proteins and lipids themselves are formed in rough and smooth endoplasmic reticulum respectively, but their conjugation with carbohydrates i.e. formation of glycoproteins and glycolipids occurs in Golgi bodies.

QUESTION: The optimum pH for the functioning of enzyme pepsin is:
A. 2
B. 3
C. 4
D. 5
EXPLANATION
Pepsin best works at pH 1.5-2. Above this pH, the acidity keeps decreasing so pepsin cannot work properly.

QUESTION: The Miller–Urey experiment determined which of the following results?
A. DNA replicates by semiconservative replication
B. Cyanobacteria were responsible for semiconservative replication
C. The early atmosphere was composed of ammonia and methane
D. Organic molecules can arise from inorganic precursors
EXPLANATION
Option D is correct since Miller–Urey provided the first evidence that organic molecules could be formed from inorganic components. Option A is incorrect since it is the result of Matthew Meselson and Franklin W. Stahls experiments. Options B and C are incorrect since both the equations were not proposed by Miller–Urey.

QUESTION: Which of the following are parts of functional classification of joints?
A. Ellipsoidal
B. Gomphosis
C. Syndesmosis
D. None of these options are correct
EXPLANATION
All the types of joints mentioned above are with respect to strutural classification.

QUESTION: Which part of the brain is responsible for long-term memory?
A. Medulla
B. Thalamus
C. Hippocampus
D. Corpus Callosum
EXPLANATION
Option C is correct since the hippocampus is responsible for encoding long-term memory. Short-term memory, also called working memory, occurs in the prefrontal cortex. (Remember this fact by the clue that since the hippocampus is like two long horns, so it contributes to long-term memory.) Option A is incorrect since the medulla plays a role in passing messages between your spinal cord and brain. Option B is incorrect since the thalamus is responsible for relaying sensory and motor signals. Option D is incorrect since the corpus callosum ensures that both sides of the brain can communicate and send signals to each other.

QUESTION: Which of the following modes of cellular transport requires energy?
A. Active transport
B. Osmosis
C. Passive transport
D. Diffusion
EXPLANATION
Option A is correct since active transport requires energy in the form of ATP. Options B and D are incorrect since both osmosis and diffusion do not require any input of extra energy to occur. They are forms of passive transport. Option C is incorrect since passive transport is the opposite of active transport and does not require energy.

QUESTION: Example of homologous organ is best representated by which structure?
A. Wing of an insect, wing of a bird
B. Leg of a dog, leg of a spider
C. The arm of a human, the wing of a bird
D. All of these options are correct
EXPLANATION
Option C is correct since the arm of a human and the wing of a bird consist of the same structure but function in a different manner i.e. they are homologous. Option A is incorrect since the wings of a bird are analogous i.e. they have different structure but perform the same function. They are not homologous. Option B is incorrect since the legs of the dog and spider have no relation. Option D is incorrect since all of the options are not correct.

QUESTION: The flap-like structure found in the larynx is called?
A. Glottis
B. Epiglottis
C. Larynx
D. Vocal cords
EXPLANATION
Option B is correct since the epiglottis is present in the upper part of the larynx, and is a flap-like projection into the throat. Options A and C are incorrect since the larynx is known as glottis which is the passageway for air between the pharynx above and the trachea below. Option D is incorrect since vocal cords are located at the top of the trachea and function in swallowing and phonation.

QUESTION: Growth and development of plant cells is the role of:
A. Parenchymatous cells
B. Chlorenchymatous cells
C. Meristematic cells
D. Sclerenchymatous cells
EXPLANATION
Option C is correct since meristematic cells are pools of undifferentiated cells that generate organs throughout the life of the plant. Option A is incorrect since parenchymatous cells help in the transportation of water and nutrients. Option B is incorrect since chlorenchyma cells are parenchymatous cells that serve the cell that promotes photosynthesis. Option D is incorrect since sclerenchymatous cells provide mechanical stiffness and strength.

QUESTION: What would you predict would happen to pancreatic enzymes if they were introduced to the stomach?
A. Their function would decrease due to increased pH
B. Their function would increase due to decreased proton concentration
C. Their function would decrease due to decreased pH
D. Their function would increase due to decreased pH
EXPLANATION
Pancreatic enzymes work in an alkaline medium in the intestine, alkylated by bile. When they will be exposed to the stomach, the pH of the surrounding will be decreased i.e. proton concentration will increase and the environment will be acidic due to the presence of HCl. So, the enzyme function will decrease.

QUESTION: Each Krebs cycle forms how many molecules of NADH?
A. 3
B. 2
C. 4
D. 1
EXPLANATION
Option A is correct since 3 NADH molecules are formed in each turn of the cycle and one FADH₂ molecule.

QUESTION: What is hydrolyzed during muscle contraction?
A. ACP
B. ADP
C. NAD
D. ATP
EXPLANATION
Option D is correct since ATP is hydrolyzed into ADP by the enzyme ATPase when it binds to myosin. Option A is incorrect since ACP provides the electrical stimulation to assist muscle contraction. Option B is incorrect since ADP is the hydrolyzed form of ATP after removal of a phosphate group. Option C is incorrect since NAD is essential to the creation of energy in the body but is not used in muscle contraction.

QUESTION: Nitrogen N₂ molecule has 3 unpaired electron on each atom, therefore it shows three bonds that are:
A. 2 sigma & 1 pi bond
B. 1 sigma & 2 pi bond
C. 3 sigma
D. 3 pi bond
EXPLANATION
Option B is correct since one sigma and two pi bonds are there as nitrogen has a triple bond between the two atoms. Options A and C are incorrect since in between two atoms, there can only be one sigma bond. Option D is incorrect since there has to be one sigma bond.

QUESTION: The density of liquids are ________ than gases but _______ to solids.
A. Lesser - closer
B. Greater - closer
C. Smaller - greater
D. Lesser - greater
EXPLANATION
Option B is correct since the density of liquids is greater than gases and close to solids as the particles are tightly packed in solid and liquid states. Options A, C, and D are incorrect since the density of liquids is not lesser than gases, it is greater due to their higher kinetic energy compared to the molecules.

QUESTION: Fossil fuels are produced due to ________.
A. Fast decomposition of organic matter
B. Decomposition of plants
C. Decomposition of animals
D. Biochemical decomposition of dead organic matter
EXPLANATION
Option D is correct since fossil fuels are the anaerobic decomposition of buried dead organisms. Option A is incorrect since the fuel formed by the decomposition of organic matter is called fossil fuels. Options B and C are incorrect since fossil fuels are made from decomposing plants and animals.

QUESTION: Free radical reactions take place in the presence of _________.
A. Heat
B. Sun light
C. Catalyst
D. Oxygen
EXPLANATION
Option B is correct since sunlight is simply a source of energy, and is being used to break bonds. Option A is incorrect since heat results in the formation of free radicals and enables the beginning of a free radical chain reaction referred to as Initiation. Option C is incorrect since catalyst is the process of increasing the rate of a chemical reaction. Option D is incorrect since free radical reactions take place in the presence of sunlight, not oxygen.

QUESTION: The organic compounds having close resemblance in structure as well as properties are:
A. Glycol and cyclohexanol
B. Formaldehyde and benzol
C. Diethyl ether and ethyl alcohol
D. Methanal and acetone
EXPLANATION
Option A is correct since glycol and cyclohexanol both bear the OH group and are similar in structure and properties. Option B is incorrect since formaldehyde is a methanol whereas benzol is an impure benzene. Option C is incorrect since diethyl is an ether and ethyl alcohol is an alcohol, they also differ in properties. Option D is incorrect since methanol refers to ethanol, which is poisonous to drink and acetone is the simplest ketone.

QUESTION: Pure metal:
A. Corrodes slowly
B. Does not corrode easily
C. Corrodes rapidly
D. None of these options are correct
EXPLANATION
Option B is correct since it does not corrode easily due to the impurities present in the pure metals. Options A and C are incorrect since pure metals do not corrode rapidly or slowly. Option D is incorrect since Option B is the right option.

QUESTION: Structure of a crystal is changed due to:
A. Cooling
B. Heating
C. Impurity
D. None of these options are correct
EXPLANATION
Option C is correct since the presence of an impurity due to its different electronic structure causes the structure of the crystal to change. Option A is incorrect since cooling affects the decrease in temperature. Option B is incorrect since heating causes the bonds between the atoms to relax. Option D is incorrect since Option C is the right answer.

QUESTION: The rate of chemical reactions helps in designing industrial processes which is:
A. Completed instantaneously
B. Slow
C. Economical
D. None of these options are correct
EXPLANATION
Option C is correct since the ultimate goal of any industry is to make as much money as possible which is possible economically. Options A and B are incorrect since the industrial process can not be completed instantaneously or be slow. Option D is incorrect since Option C is the right option to choose.

QUESTION: The mass of one mole of electron is:
A. 1.8 mg
B. 0.184 mg
C. 0.55 mg
D. 0.64 mg
EXPLANATION
Option C is correct since we can calculate the mass of one mole of electron by multiplying the mass of an electron and the mole it contains. Options A, B, and D are incorrect since 0.64 mg, 0.184 mg, and 1.8 mg are not the right answers

QUESTION: If both alkyl groups attached to the carbonyl in ketone are the same, then it is called as:
A. Mixed
B. Unsymmetrical
C. Symmetrical
D. None of these options are correct
EXPLANATION
Option C is correct since when alkyl groups are attached to the carbonyl they are said to be symmetrical. Options A and B are incorrect since in mixed and unsymmetrical the phase are either one or two involved. Option D is incorrect since Option C is the right answer.

QUESTION: Positive rays are produced when _________ strike the molecules of a gas in a discharge tube.
A. Low speed neutrons
B. High speed neutrons
C. Low speed electrons
D. High speed electrons
EXPLANATION
Option D is correct since high speed electrons strike the discharge tube. Option A and B are incorrect since neutrons dont strike the discharge tube. Option C is incorrect since having low speed electrons wont be able to strike the discharge tube.

QUESTION: In the Habers process, the final product ammonia is converted into:
A. Solid state
B. Liquid state
C. Gaseous state
D. None of these options are correct
EXPLANATION
Option B is correct since after the gases are cooled in step 3 ammonia turns into liquid. Option A is incorrect since ammonia is a colourless gas with a pungent smell. Option C is incorrect since ammonia is converted to liquid state. Option D is incorrect since Option B is the right option.

QUESTION: Which of the following element is not usually present in all proteins?
A. Carbon
B. Hydrogen
C. Nitrogen
D. Sulfur
EXPLANATION
Option D is correct since sulfur is present in less amount among the other amino acids. Options A, B, and C are incorrect since they are elements of amino acids found in all living organisms

QUESTION: A piston in a cylinder is a part of the:
A. System
B. Surroundings
C. Boundary
D. None of these are correct
EXPLANATION
Option B is correct since a piston is a moving disk enclosed in a cylinder that surrounds the cylinder. Options A and C are incorrect since the piston is not present in the system or boundary of the cylinder Option D is incorrect since Option B is the right option.

QUESTION: A chemical reaction has reached to a state of dynamic equilibrium at certain temperature. Which of the following statements is incorrect?
A. Concentration of the reactants remains constant
B. Products are continuously being formed
C. The rate of forward and backward reactions are the same
D. The reaction has stopped completely
EXPLANATION
Option D is correct since when a reaction reaches the dynamic equilibrium it certainly cannot be stopped. Options A, B, and C are incorrect since all the statements happen to be in the dynamic equilibrium reaction.

QUESTION: If the difference of electronegativity is 1.7 or more than that, the bond formed is said to be:
A. Ionic bond
B. Covalent bond
C. Metallic bond
D. Chemical bond
EXPLANATION
Option A is correct since if electronegativity is 1.7 or more than that, then will have an ionic bond. Options B and C are incorrect since covalent or metallic bonds will be present when electronegativity is <0.5.

QUESTION: The non-protein part co-factor includes organic and metallic organic molecules and sometimes ________.
A. Vitamins
B. DNA
C. Coenzyme
D. None of these options are correct
EXPLANATION
Option A is correct since most vitamins are organic. Options B and C are incorrect since they are not organic molecules. Option D is incorrect since Option A is the right answer.

QUESTION: Which of the following has the lowest vapor pressure ?
A. Glycerol
B. Isopentane
C. Ethanol
D. Both Options A and C are correct
EXPLANATION
Option A is correct since the strength of glycerol intermolecular forces lead to the compound having lower vapor pressure. Option B is incorrect since isopentane has a high vapor pressure due to a lack of bonding present. Option C is incorrect since ethanol does not have lower vapor pressure than isopentane. Option D is incorrect since Option A and C are both wrong.

QUESTION: The reaction in which a nucleophile replaces another atom present in a compound is called as:
A. Nucleophilic elimination reaction
B. Nucleophilic addition reaction
C. Nucleophilic substitution reaction
D. All of these options are correct
EXPLANATION
Option C is correct since the given statement is the definition for the nucleophilic substitution reaction. Option A is incorrect since a nucleophilic elimination reaction is in which an electron nucleophile bonds with or attacks the partially positive charge of a group of atoms to replace the leaving group. Option B is incorrect since a nucleophilic addition reaction is a chemical addition reaction in which a nucleophile forms a sigma bond with an electron deficient species Option D is incorrect since not all of the options are correct.

QUESTION: Law of conservation of energy is actually:
A. Second law of thermodynamics
B. Third Law of Thermodynamics
C. First Law of Thermodynamics
D. Zeroth law of Thermodynamics
EXPLANATION
Option C is correct since first law of thermodynamics is known as law of conservation of energy Option A is incorrect since the second law of thermodynamics is known as the Clausius statement. Option B is incorrect since the third law of thermodynamics is about the entropy of a system. Option D is incorrect since there is no zeroth law of thermodynamics.

QUESTION: Change in pressure will only affect the substance which are in:
A. Liquid state
B. Solid State
C. Plasma state
D. Gaseous state
EXPLANATION
Option D is correct since when you increase the pressure, the molecules have less space in which they can move. Thats why pressure only affects substances in the gaseous state. Options A, B, and C are incorrect since the pressure only affects the gaseous state not solid or liquid.

QUESTION: The number of reacting molecules which changes their concentration in a chemical change is called:
A. Extent of a reaction
B. Order of a reaction
C. Specific rate of a reaction
D. Enthalpy of reaction
EXPLANATION
Option B is correct since the statement is known as the definition of the order of a reaction. Option A is incorrect since the extent of a reaction determines how long the reaction has proceeded. Option C is incorrect since the specific rate of a reaction is equal to the rate constant of reaction when the concentration of the reactant in unity. Option D is incorrect since the enthalpy of a reaction measures the heat released/absorbed by a reaction that occurs at constant pressure.

QUESTION: The platinum in standard hydorgen electeode acts as a:
A. Buffer
B. Salt Bridge
C. Electrical Conductor
D. All of these options are correct
EXPLANATION
Option C is correct since platinum does not engage in the reaction of the cells but provides an oxidation and reduction reaction surface. Options A and B are incorrect since the platinum roles are not as a buffer or a salt bridge. Option D is incorrect since all of the options arent correct.

QUESTION: Enthalpy of a system is given as _______?
A. ∆H = qv + w
B. ∆H = E + PV
C. ∆H = qp + PV
D. ∆H = E
EXPLANATION
Option B is correct since the enthalpy of a system is defined as the sum of its internal energy and the product of its pressure and volume. Options A, C, and D are incorrect since they dont follow the definition of enthalpy of a reaction.

QUESTION: Which of the following derivative of carboxylic acid is used as a flavoring agent?
A. Acid halides
B. Acid carbonyls
C. Esters
D. Acid amides
EXPLANATION
Option C is correct since esters are sweet-smelling liquids that can be used as flavoring agents. Option A is incorrect since acid halides are primarily used in organic syntheses to introduce the acyl group. Options B and D are incorrect since they are used to form resilient structural materials.

QUESTION: In chemical combination of H-atom with sodium, it gains an electron but in the case of HF, the H-atom:
A. Gains 2e^-
B. Loses 1e^-
C. Loses 2e^-
D. Gains 1e^-
EXPLANATION
Option B is correct since in the case of HF, the H-atom will lose 1e^- as F tends to gain electrons.

QUESTION: Evaporation is the reverse of ________?
A. Sublimation
B. Freezing
C. Melting
D. Condensation
EXPLANATION
Option D is correct since in evaporation water droplets are heated and converted into water vapors whereas condensation from air droplets are formed. Options A and C are incorrect since they are the reverse of Option B which is freezing.

QUESTION: Which element is required for making Chlorophyll in leaves?
A. Si
B. Ba
C. Mg
D. Ca
EXPLANATION
Option C is correct since Mg is only present in chlorophyll. Option A is incorrect since Si has beneficial effects on the growth and production of a wide range of plant species. Option B is incorrect since Ba is not present in plants. Option D is incorrect since Ca is present in the soils.

QUESTION: The hydrocarbon in which all the 4 valencies of carbon are fully occupied is called as ______.
A. Alkene
B. Alkyne
C. Alkane
D. Cycloalkane
EXPLANATION
Option C is correct since when all the valencies of carbon atoms are fully utilized by single covalent bonds known as Alkanes. Option A is incorrect since Alkenes have double bonds. Option C is incorrect since Alkynes have triple bonds. Option D is incorrect since in cycloalkanes the carbon atoms are joined in a ring.

QUESTION: In an electrochemical cell, negative ions are migrated towards:
A. Anode
B. Cathode
C. Towards the bottom of the cell
D. Towards the walls of the cell
EXPLANATION
Option A is correct since each electrode attracts ions that are of the opposite charge so, they migrate towards the anode. Option B is incorrect since they are negative charge ions. Options C and D are incorrect since either they will move towards anode or cathode.

QUESTION: The average and instantaneous rate can be equal:
A. Throughout the reaction
B. Near reaction completion
C. At one instant only
D. At the start of the reaction
EXPLANATION
Option C is correct since at one instant when time becomes infinitesimally small. Options A, B and D are incorrect since it will be equal when the time is 0.

QUESTION: Which of the following product is formed when aldol product is heated?
A. Rearrangement
B. Dehydration
C. Decomposition
D. All of these options are correct
EXPLANATION
Option B is correct since when aldol heating eliminates a molecule of water i.e. it undergoes dehydration. Options A and C are incorrect since rearrangement and decomposition is not formed when aldol is heating. Option D is incorrect since all of the options are not correct.

QUESTION: Ketones can be oxidized by ________?
A. Dilute HNO₃
B. Tollens reagent
C. Benedict reagent
D. Fehlings reagent
EXPLANATION
Option A is correct since there are two reactions that can oxidize ketones. One of them is by Dilute HNO₃. Option B is incorrect since ketones will not be able to oxidize Tollens reagent as it wont produce a silver mirror in the test tube. Options C and D are incorrect since ketones do not react with Benedict or Fehlings solution.

QUESTION: The value of Principal quantum number n represents:
A. Energy of electron
B. Location of electron
C. Shells or energy levels
D. All of these options are correct
EXPLANATION
Option C is correct since it represents the relative overall shells or energy of each orbital. Option A is incorrect since it also represents the shells of electron Option B is incorrect since it does not represent the location of an electron. Option D is incorrect since all of the options are not correct.

QUESTION: Carboxylic acids are formed by the hydrolysis of ________.
A. Ester and Nitriles
B. Nitriles and amines
C. Alkenes and Alkynes
D. Ester and Alcohols
EXPLANATION
Option A is correct since the hydrolysis of Ester and Nitriles form carboxylic acid Options B, C, and D are incorrect since they cant form carboxylic acid.

QUESTION: Why does Cr show 3d⁵4s¹ configuration instead of 3d⁴4s²?
A. Because it is transition element
B. Because it shows different oxidation states
C. Because of extra stability of half filled d⁵ system
D. Because it is typical transition element
EXPLANATION
Option C is correct since due to the gain of additional stability by the atom by having a half-filled configuration. Option A is incorrect since it does not matter if Cr is a transition metal or not. Options B and D are incorrect since it does not affect the electronic configuration.

QUESTION: Avogadros hypothesis is applicable to _______ only.
A. All gases
B. Inert gases
C. Ideal gases
D. Light gases
EXPLANATION
Option C is correct since ideal gases are the chemical formulas of gaseous substances on the basis of combining gas volumes. Options A, B, and D are incorrect since the inert or light gases do not follow Avogadros hypothesis.

QUESTION: If the temperature of reaction medium increases above the optimum temperature, then _______?
A. It increases the enzyme activity
B. Stops the reaction
C. Decreases the enzyme activity
D. Both Options B and C are correct
EXPLANATION
Option D is correct since both Options B and C are correct. Option A is incorrect since enzyme activity wont be increased. Options B and C are incorrect since both are possible.

QUESTION: The shape of KNO₃ above 128˚C is:
A. Cubic
B. Orthorhombic
C. Rhombohedral
D. Tetragonal
EXPLANATION
Option C is correct since at 128˚C KNO₃ adopts the rhombohedral R3-M space group. Options A, B, and D are incorrect since at 128˚C, KNO₃ shape is not cubic or orthorhombic.

QUESTION: The number of atoms present in a molecule determines its:
A. Shape
B. Size
C. Molecularity
D. Atomicity
EXPLANATION
Option D is correct since atomicity is the total number of atoms present in one molecule. Options A and B are incorrect since shape is determined by the number of electron pairs present. Option C is incorrect since molecularity is equal to the sum of the stoichiometric coefficients of the reactants in the chemical equation of the reaction.

QUESTION: During SN₁ mechanism, the nucleophile can attack on the halogen carbon ___________.
A. From the opposite side of the leaving group
B. From the front of the leaving group
C. From both sides
D. None of these options are correct
EXPLANATION
Option C is correct since nucleophiles can attack the halogen carbon from both sides. Options A and B are incorrect since nucleophiles can attack the halogen carbon from either side. Option D is incorrect since Option C is the right option.

QUESTION: Phenols react with calcium carbonate and produce _________.
A. H₂ gas
B. CO₂ gas
C. O₂
D. None of these options are correct
EXPLANATION
Option D is correct since none of the given options are correct. Options A, B, and C are incorrect since it does not evolve H₂, CO₂ or O₂ gas.

QUESTION: Phenol was obtained for the first time from?
A. Coke
B. Pitch
C. Aromatic compounds
D. Coal tar
EXPLANATION
Option D is correct since phenol was first obtained from coal tar by Friedlieb Ferdinand Runge. Options A, B, and D are incorrect since phenol was not obtained from coke, pitch, or aromatic compounds.

QUESTION: Friedrich Wöhler prepared urea from:
A. Amino Acids
B. Ammonium carbonate
C. Ammonium cyanate
D. Xanthin
EXPLANATION
Option C is correct since ammonium cyanate was the first generally accepted laboratory synthesis of a naturally occurring organic compound from inorganic materials. Options A, B and D are incorrect since urea is not prepared from amino acids or xanthin.

QUESTION: Oxygen is not released on heating which of the following compounds?
A. (NH₄)₂Cr₂O₇
B. K₂Cr₂O₇
C. Zn(ClO₃)^2-
D. KClO₃
EXPLANATION
Option A is correct since ammonium dichromate cant release oxygen because of thermal decomposition. Options B, C, and D are incorrect since oxygen is released on heating in those compounds.

QUESTION: Enzymes which bring about exchange of a functional group are called _______.
A. Oxidoreductase
B. Hydrolases
C. Ligases
D. Transferases
EXPLANATION
Option D is correct since the given statement is the definition of transferases. Option A is incorrect since oxidoreductase is an enzyme that catalyzes the transfer of electrons from one molecule. Option B is incorrect since hydrolases are enzymes that catalyze the cleavage of a covalent bond using water. Option C is incorrect since ligases are enzymes that catalyze the formation of chemical bonds.

QUESTION: If we decrease temperature of a gas by 2 times, its volume will:
A. Increase by 4 times
B. Decrease by 4 times
C. Decrease by 2 times
D. Increase by 2 times
EXPLANATION
Option C is correct since temperature and volume are directly proportional to each other so it will also decrease by two times. Options A and D are incorrect since volume will also decrease and it will increase when temperature will increase. Option B is incorrect since the volume will decrease by two times.

QUESTION: Drawing a graph between concentration change with time gives us a:
A. Straight line
B. Parabola
C. Curve
D. Scattered graph
EXPLANATION
Option C is correct since as shown in the picture the concentration of a reactant is measured at intervals as the reaction occurs. Options A, B, and D are incorrect since the graph wont be of a straight line or scattered or parabola.

QUESTION: Which of the following is not a state function?
A. Internal Energy
B. Enthalpy
C. Work
D. None of these options are correct
EXPLANATION
Option C is correct since work can not be a state function as it is proportional to the distance an object is moved. Options A and B are incorrect since internal energy and enthalpy are state functions. Option D is incorrect since Option C is the right answer.

QUESTION: Which of the following compounds evolve Carbon Dioxide on reacting with sodium bicarbonate?
A. CH₃COOCH₃
B. CH₃CH₂OH
C. CH₃CH₂COOH
D. CH₃COOOCH₃
EXPLANATION
Option C is correct since propanoic acid evolves carbon dioxide on reaction with sodium bicarbonate. Options A, B, and D are incorrect since the given options does not evolve carbon dioxide with sodium bicarbonate.

QUESTION: In groups of the periodic table, the removal of electrons from the valence shell is easy due to:
A. Addition of electrons
B. Addition of shells
C. Increase in nuclear charge
D. Strong attractive forces
EXPLANATION
Option B is correct since by the addition of shells it is easy to remove electrons as a neutral atom turns the atom into an ion. Option A is incorrect since the addition of electrons will increase the negative charge and put stress on the electrons already there, causing energy to be released. Options C and D are incorrect since they will cause greater attraction to the electrons.

QUESTION: In the case of the oxidation of symmetrical ketone, which of the following products are formed?
A. One carboxylic acid
B. Mixture of different carboxylic acids
C. Same type of carboxylic acids
D. None of these options are correct
EXPLANATION
Option C is correct since symmetrical ketones are prepared from carboxylic acids, so it will be the same type of carboxylic acid. Options A and B are incorrect since not one or a mixture of carboxylic acid can be formed. Option D is incorrect since Option C is the right answer.

QUESTION: In sp₂ hybridization, the orbital orientation is:
A. 109.5˚
B. 180˚
C. 90˚
D. 120^˚
EXPLANATION
Option D is correct since in a trigonal planar, triangular geometry the orbitals are oriented with 120˚ angles. Option A is incorrect since in sp₃ hybridization the orbitals are oriented with 109.5˚ angles. Option B is incorrect since in sp hybridization the orbitals are oriented with 180˚ angles. Option C is incorrect since in sp₂ hybridization the orbital orientation is 120˚ not 90˚.

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 options are correct
EXPLANATION
Option B is correct since heat is transferred from one body to another across the boundaries of the system. Options A and C are incorrect since heat flows across the boundaries not surroundings or within the system. Option D is incorrect since not all of the options are correct.

QUESTION: Cesium in cesium chloride has the coordination number:
A. 6
B. 8
C. 4
D. 5
EXPLANATION
Option B is correct since it occupies the center of the cube which is 8 in number. Options A, C, and D are incorrect since 6, 4, and 5 are less in number to occupy the center of a cube.

QUESTION: Which of following is an example of electrophilic attack on alcohol?
A. C₂H₅OH + CH₃COOH H₂SI₄
B. 2C₂H₅0H + 2Na ____2CH₅0Na + H₂
C. C₂S₅OH + HCl ZnClL₂ C₂H₅CL+ H₂0
D. Both Options A and B are correct
EXPLANATION
Option D is correct since both Option A and B show electrophilic attack on alcohols. Option A is incorrect since not only this option shows electrophilic attack on alcohols. Option B is incorrect since not only this option shows electrophilic attack on alcohols. Option C is incorrect since the reaction is not an electrophilic attack on alcohols.

QUESTION: 1 rutherford is equal to ____.
A. 10⁴ Bq
B. 10⁶ Bq
C. 10⁷ Bq
D. 10⁵ Bq
EXPLANATION
Option B is correct since one Rutherford is 10⁶ Bq as 1,000,000 nuclear disintegrations per second. Options A, C, and D are incorrect as we know one Rutherford is 10⁶ Bq.

QUESTION: A current of 5A flows in a resistor of 2 Ohms. Calculate the energy dissipated in 300 seconds in the resistor.
A. 5 kJ
B. 10 kJ
C. 15 kJ
D. 20 kJ
EXPLANATION
Option C is correct since by applying the formula P = I²R = 5²x2 = 50W Then, E = PxT = 50x300 = 15,000 WS = 15 kJ.

QUESTION: The angular displacement of an object after one complete revolution is ____.
A. 0 radian
B. π radian
C. 2π radian
D. (1/3)π radian
EXPLANATION
Option C is correct since we know that θ=2π as when a particle travels the radius of the circle goes through a change in angle Δθ which equals the angular displacement. Options A, B, and D are incorrect since the correct option is 2π radian.

QUESTION: Electron charge in accelerating motion will produce ____.
A. Electric field
B. Magnetic field
C. Electromagnetic waves
D. None of these options are correct
EXPLANATION
Option C is correct since EM waves are produced when an electron produces an electric field that is changing, and this produces a changing magnetic field. Option A is incorrect since electric fields are produced when forces act at a distance between two charges. Option B is incorrect since a magnetic field is produced when an electron spins. Option D is incorrect since Option C is the right option.

QUESTION:

Calculate the wavelength of a photon associated with 3 x 10¹⁴ Hz frequency.

A.

10 micrometer

EXPLANATION

Option C is correct since we know the formula for the wavelength is c/v;

3 x 10⁸ / 3 x 10¹⁴= 1 micrometer.

Options A, B, and D are incorrect since the answer is neither 10, 100, nor 2 micrometers.

QUESTION: If an object moves with constant velocity, then its acceleration is _____.
A. Zero
B. Non-zero
C. Infinite
D. None of these options are correct
EXPLANATION
Option A is correct since acceleration will be zero as there is no net force acting on an object. Option B is incorrect since the acceleration will be non-zero when there is a change in velocity. Option C is incorrect since infinite acceleration is impossible. Option D is incorrect since Option A is the right option.

QUESTION: The waves which propagate by the oscillation of material particles are called ______.
A. Matter waves
B. Mechanical waves
C. Electromagnetic waves
D. Microwaves
EXPLANATION
Option B is correct since the given statement is the definition of mechanical waves. Option A is incorrect since matter waves are a central part of the theory of quantum mechanics. Option C is incorrect since electromagnetic waves consist of waves of the electromagnetic field, propagating through space. Option D is incorrect since a microwave is a form of electromagnetic radiation with wavelengths.

QUESTION: The oscillating object overshoots the rest position due to _____.
A. Restoring force
B. Inertia
C. Gravitational potential energy
EXPLANATION
Option B is correct since the rest position is overshot due to inertia as a system loses energy, the amplitude falls. Option A is incorrect since restoring force causes the body to oscillate. Option C is incorrect since the gravitational potential energy increases. Option D is incorrect since the elastic potential energy is completely converted into kinetic energy when the object starts to move.

QUESTION:

According to Faradays law, EMF stands for _____.

A.

Electromagnetic friction

EXPLANATION

Option B is correct since electromagnetic force is the force in any closed circuit due to the change in the flux linkage of the circuit.

Option A is incorrect since electromagnetic friction is the resistance to motion of one object moving relative to another. It is not a fundamental force.

Option C is incorrect since the function of an electromagnet is to send electricity through a coil of wire to produce a magnetic field.

Option D is incorrect since Option B is the right answer.

QUESTION: The current passing through a conductor is directly proportional to the potential difference applied across its terminals, provided the temperature and other physical conditions of the conductor does not change.
A. Gausss law
B. Lenzs law
C. Pascals law
D. Ohms law
EXPLANATION
Option D is correct since the given statement is of Ohms law. Option A is incorrect since Gausss law is that “the electric flux through any closed surface is proportional to the total electric charge enclosed within that closed surface”. Option B is incorrect since Lenzs law is “An induced electric current flows in a direction such that the current opposes the change that induced it”. Option C is incorrect since Pascals law is “Pressure applied anywhere in a confined incompressible fluid is transmitted equally in all directions throughout the fluid”.

QUESTION: Which of the following is not a type of rectifier?
A. Phase wave rectifier
B. Full wave
C. Half wave
D. None of these options are correct
EXPLANATION
Option A is correct since a phase wave rectifier is a device that rectifies the input AC voltage. Options B and C are incorrect since half and full waves are the types of a rectifier. Option D is incorrect since option A is the right answer.

QUESTION: Work done by friction _____.
A. Can be zero
B. Can be positive
C. Can be negative
D. All of these options are correct
EXPLANATION
Option D is correct since all of the options can be correct according to the question. Options A, B, and C are incorrect since the work done can be positive, negative or zero, it depends on the direction of the motion.

QUESTION: An electron is held within an electric field. What happens when the electron is released?
A. It moves in the direction of the electric field
B. It accelerates in the direction of the electric field
EXPLANATION
Option D is correct since the electron will accelerate opposite the direction of the field as the force on the electron due to the electric field is F = qE. Options A and C are incorrect since electrons will move in the opposite direction of the electric field because of its negative charge. Option B is incorrect since electrons are accelerated when an electric field is constantly applied.

QUESTION: If the velocity of an object is increasing with time, then acceleration is _____.
A. Negative
B. Positive
C. Zero
D. None of these options are correct
EXPLANATION
Option B is correct since when velocity increases acceleration will be positive as acceleration is the rate of change of velocity with time. Option A is incorrect since the acceleration will be negative when the velocity decreases. Option C is incorrect since acceleration is zero when the initial velocity equals average velocity. Option D is incorrect since Option B is the correct option.

QUESTION: Michelsons interferometer is an instrument that can be used to measure _____.
A. Speed
B. Frequency
C. Distance
D. Amplitude
EXPLANATION
Option C is correct since the distance is measured by the wavelength of the light. Options A, B, and D are incorrect since the device failed to measure the speed of light, whereas frequency and amplitude cannot be measured.

QUESTION: The down quark has charge _____.
A. -1/2
B. +1/2
C. -1/3
D. +2/3
EXPLANATION
Option C is correct since it is written that each down quark has a charge of -1/3. Options A, B, and D are incorrect since the correct Option is C.

QUESTION: An element X with Z=14 and A=6 has how many neutrons?
A. 6
B. 8
C. 14
D. 20
EXPLANATION
Option B is correct since neutrons are calculated by the formula A-Z. So, 14-6 = 8 neutrons. Options A, C, and D are incorrect since 6, 14, and 20 are wrong answers.

QUESTION: The minute hand of a large clock is 3.0 m long. What is its mean angular speed?
A. 1.4 x 10^-4 rads^-1
B. 1.0 x 10^-3 rads^-1
C. 5.2 x 10^-3 rads^-1
D. 1.7 x 10^-3 rads^-1
EXPLANATION
Option C is correct since the formula for angular velocity= r x w w = 2π / t, 2(3.142) / 3600 = 1.745 x 10^-3 rad/s Angular velocity = 3 x 1.745 x 10^-3 = 5.2 x 10^-3 rad/s Options A, B, and D are incorrect since the options given are wrong answers.

QUESTION: Plancks constant is analogous to _____.
A. Inertia
B. Wave nature
C. Angular momentum
D. Linear momentum
EXPLANATION
Option C is correct since the angular momentum dimensions are equal to the dimensions of Plancks constant. Options A, B, and D are incorrect since inertia, wave nature and linear momentum are not analogous to Plancks constant in any way.

QUESTION: The phenomenon of radioactivity is ______.
A. Nuclear process does not depend on external factors
B. Increased on applied pressure
C. Exothermic change which increases and decreases with temperature
D. None of these options are correct
EXPLANATION
Option A is correct since the nuclear receptor does not depend on external factors is the important fact of radioactivity. Option B is incorrect since radioactivity is a nuclear process it is considered to be insensitive to external factors such as pressure. Option C is incorrect since temperature does not affect radioactivity at all. Option D is incorrect since Option A is correct.

QUESTION: A thermodynamic system undergoes a process in which its internal energy decreases by 300 J. If at the same time 120 J of work is done on the system, find the heat lost by the system.
A. -420 J
B. 420 J
C. 80 J
D. -80 J
EXPLANATION
Option A is correct since from the law of thermodynamics we know that: ΔU = Q+W , −ΔU−W = Q (minus sign indicates that internal energy is decreased) −300 J−120 J= −420 J Option B is incorrect since it does not show the minus sign. Options C and D are incorrect since 80 and−80 are the wrong answers.

QUESTION: The length of a conductor is halved. Its resistance will be _____.
A. Halved
B. Doubled
C. Unchanged
D. Quadrupled
EXPLANATION
Option A is correct since the resistance will be halved as resistance is directly proportional to the length of the conductor. Option B is incorrect since the resistance will be doubled when the length of the conductor will be doubled. Option C is incorrect since the resistance will be changed as the length of the conductor is changed to halved. Option D is incorrect since the resistance will quadruple when the length of the conductor will be quadruple.

QUESTION: When a charged particle enters in a strong magnetic field, its kinetic energy ______.
A. Decreases
B. Increases then decreases
C. Becomes zero
D. Remains constant
EXPLANATION
Option D is correct since the magnetic field does not work, so the K.E will remain constant. Options A and B are incorrect since magnetic forces do not work on charged particles and cannot increase their kinetic energy. Option C is incorrect since kinetic energy is based on motion, if it is not in motion then kinetic energy of that object is zero.

QUESTION: Gamma rays travel ______ distance.
A. Long
B. Short
C. Absorbed immediately
D. Never ending distance
EXPLANATION
Option A is correct since gamma rays have short wavelengths so they can pass through space. They have very high kinetic energy and they have a smaller rate of collision with the atoms (or molecules) of the medium.

QUESTION: If a particle having a charge q is accelerated through a potential difference V, then the energy acquired by the particle is _______.
A. V/2
B. V/q
C. qV/2
D. qV
EXPLANATION
Option D is correct since to find the energy we multiply the charge moved by the potential difference so, E = qv. Options A, B, and C are incorrect since the options are wrong.

QUESTION: The concept of work function was given by ______.
A. Bohr
B. Einstein
C. Rutherford
D. None of these options is correct
EXPLANATION
Option B is correct since Einstein takes energy for an electron and calls this energy the work function. Option A is incorrect since Bohr discovered that electrons travel in separate orbits around the nucleus. Option C is incorrect since Rutherford discovered the alpha and beta rays. Option D is incorrect since Option B is the right option.

QUESTION: Harmonics in transformer result in ____.
A. Increased core loss
B. Increased I²R loss
C. Interference with communication circuits
D. All of these options are correct
EXPLANATION
Option D is correct since all of the options are correct. Options A, B and C are incorrect since not only harmonics in transformers result in increase in core loss and an increase in 2R loss due to the increase in voltage.

QUESTION: e/m = ____
A. mv/Br
B. v/Br
C. r/Bv
D. B/vr
EXPLANATION
Option B is correct since we know that: Fm = Fc evB = mv²/r eB = mv/r e/m = v/Br Options A, C, and D are incorrect since the options are incorrect.

QUESTION:

Electric potential difference between two points can be defined as ______.

A.

Difference of the kinetic energy per unit charge

EXPLANATION

Option C is correct since we can write electric potential as energy/charge, now we can understand that the potential difference between two different points will be equal to the change in potential energy of a unit charge when it moves from one point to the other.

Option A is incorrect since the energy per unit charge is voltage.

Option B is incorrect since kinetic energy is energy in motion, actively using energy for movement.

Option D is incorrect since potential energy is stationary, with stored energy to be released.

QUESTION: A car is moving in a circular track of diameter 100m at a constant speed of 40m/sec. Find the centripetal acceleration.
A. 42 m/s²
B. 52 m/s²
C. 32 m/s²
D. 30 m/s²
EXPLANATION
Option B is correct since by applying the formula of centripetal acceleration = v² / r r = d / 2 (convert nm into m) Centripetal acceleration = 40² / 5 x 10¹ = 32 m/sec² Options A, C, and D are incorrect since the options are wrong.

QUESTION: How many down quarks are there in neutron?
A. 1
B. 2
C. 3
D. 4
EXPLANATION
Option B is correct since neutrons have 2 down quarks. Option A is incorrect since neutrons have one up quark. Option C is incorrect since in total neutrons have 3 quarks. Option D is incorrect since a neutron does not have 4 quarks.

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 C is correct since F = k q₁q₂ / d² So, F = kq₁q₂/ (d² / 4) F = 4 (kq₁q₂ / d²) F = 4F Options A, B, and D are incorrect since by applying the formula the options arent correct.

QUESTION: If a charge particle enters in a region where electric and magnetic field are parallel to its motion, then it will ______.
A. Deflect upwards
B. Deflect downwards
C. Speed up
D. Speed down
EXPLANATION
Option C is correct since the magnetic and electric fields are parallel to each other so the charge will speed up. Options A, B, and D are incorrect since the magnetic and electrical fields are parallel to each other.

QUESTION: An electric filament bulb can work only on a ______.
A. DC supply only
B. AC supply only
C. Battery supply only
D. All of the above options are correct
EXPLANATION
Option D is correct since all of the options can supply electric current to the bulb. Option A is incorrect since not only D.C supply can supply electric current to the electric filament bulb through its constant flow of current. Option B is incorrect since not only A.C supply can also be used for glowing electric filament in an electric bulb. Option C is incorrect since not only does the battery supply electric current to the bulb through its electrons made of current.

QUESTION: The Davisson Germer experiment is used to explain ______.
A. Interference
B. Polarization
C. Diffraction
D. None of these options are correct
EXPLANATION
Option C is correct since the Davisson Germer experiment is used for the diffraction effect of the electron. Options A and B are incorrect since the Davisson Germer experiment is not for interference or polarization. Option D is incorrect since Option C is the right answer.

QUESTION: Maximum power is delivered when internal resistance of the source is equals to ___.
A. Zero resistance
B. Load resistance
C. Max resistance
D. None of these options are correct
EXPLANATION
Option B is correct since the load must equal the resistance of the source as viewed from its output terminals. Options A and C are incorrect since it equals zero resistance when connected to an open circuit. Option D is incorrect since Option B is the right answer.

QUESTION: The first law of thermodynamics can be stated as _____.
A. Q = ΔU +W
B. Q + ΔU = W
C. Q = ΔU - W
D. Q = ΔU * W
EXPLANATION
Option A is correct since the first law of thermodynamics is that the change in internal energy of a system equals the net heat transfer into the system minus the net work done by the system. Option B is incorrect since it states that the change in internal energy of a system equals the work done by the system minus the net heat transfer. Option C is incorrect since it states that the change in internal energy of a system equals the work done by the system plus the net heat transfer. Option D is incorrect since it states that the change in internal energy of a system equals the work done by the system divided by the net heat transfer.

QUESTION:

Under what conditions of density and pressure does a real gas approximate to an ideal gas?

A.

Density=high, pressure=high

EXPLANATION

Option D is correct since real gas can be approximated as ideal gas when the pressure is low and the temperature is high.

Options A, B, and C are incorrect since real gas can not be approximated as ideal gas when the pressure is high.

QUESTION: A particle of mass m is projected from the ground with an initial speed u₀ at an angle a with the horizontal. At the highest point of its trajectory, it makes a completely inelastic collision with another particle of mass which was thrown vertically upward from the ground with the same initial speed u₀. The angle that the composite system makes with the horizontal immediately after the collision is _____.
A. 37˚
B. 45˚-a
C. 45˚+a
D. 90˚
EXPLANATION
Option A is correct since by applying the formula shown in the picture of v1 and v2. We have to compare v1 and v2, then we will know the answer. Options B, C, and D are incorrect since they dont follow the formula given in the picture.

QUESTION: A monochromatic light is incident on two slits and an interference pattern is produced on a screen at distance L. Now one slit is covered, and no light comes from it. What is the change in pattern on the screen?
A. The width of central maximum is decreased
B. The width of outer maximum is decreased
C. The intensity of central maximum will decrease
D. Less number of fringes will be observed
EXPLANATION
Option D is correct since there will be less fringes on the screen since one slit is covered and no light coming from it. Options A and B are incorrect since the width cant be decreased or increased. Option D is incorrect since the intensity cant be affected.

QUESTION: A body moves a distance of 10 m along a straight line under the action of 5 N force. If work done is 25 J, then angle between the force and direction of motion of the body will be ______.
A. 75˚
B. 60˚
C. 45˚
D. 30˚
EXPLANATION
Option B is correct since we know that, W = FS cosθ Cosθ = W / FS Cosθ = 25 / 50 Cosθ = 1 / 2 θ = 60 Options A, C, and D are incorrect since they do not apply the formula.

QUESTION: A 300 W heater is used to boil 500g of water at 100˚C. How long should the heater be switched on? (The specific latent heat of vaporization of water is 2230 J/g)
A. 62 mins
B. 62 secs
C. 1.5 hour
D. 0.5 hour
EXPLANATION
Option A is correct since we know that, mc / p So t = 500 x 2230 / 300 = 3717s t = 3717 / 60 = 62 mins Options B, C, and D are incorrect since the options given dont follow the given formula.

QUESTION: A body of mass 10 kg is moved parallel to the ground, through a distance of 2 m. The work done against gravitational force is ____.
A. Zero
B. 196 J
C. -196 J
D. 48 J
EXPLANATION
Option A is correct since gravitational force only works perpendicular to the ground, so no work is done against gravitational force. Options B, C, and D are incorrect since no work can be done against gravitational force.

QUESTION: A stationary wave is set up on a string that is fixed at both ends. The frequency of the wave is 400 Hz. If the speed of the wave is 480 m/s, then what is the length of the string?
A. 1.2m
B. 0.84m
C. 0.60m
D. 0.42m
EXPLANATION
Option A is correct since by applying the formula: F = v / 2L 2L = v / F , 2L = 480 / 400 = 1.2 / 2 = 0.60 m Options B, C, and D are incorrect since the given options are wrong answers.

QUESTION: The energy input to an engine is 4.00 times greater than the work it performs. What is its thermal efficiency?
A. 4.00
B. 1.00
C. 0.25
D. Impossible to determine
EXPLANATION
Option C is correct since 1 / 4 = 0.25 Options A, B, and D are incorrect since they are wrong answers.

QUESTION: Uranium-238 forms thorium-234 after radioactive decay and has a half-life of 4.5 x 10⁹ years. How many years will it take to decay 75% of the initial amount?
A. 9 x 10⁹ years
B. 4 x 10⁹ years
C. 9 x 10¹⁰years
D. 4 x 10¹⁰ years
EXPLANATION
Option A is correct since if 75% has decayed, that means there is 25% left. After one half life you have 50%, after two half life periods you have 50% of the 50%, or 25%. Then 4.5 x 10⁹ is two times = 9 x 10⁹ years. Options B, C, and D are incorrect since the options aren’t correct.

QUESTION: Lorentz force in electric and magnetic field is ______.
A. F = qv(E+B)
B. F = qE(v+B)
C. F = qvB
D. F = q(E+vB)
EXPLANATION
Option D is correct since the Lorentz force refers specifically to the formula for the magnetic force, with the total electromagnetic force. Options A and B are incorrect since both the formula does not follow the Lorentz force definition. Option C is incorrect since the F = qvB formula is obtained after the definition of magnetic field or cross product.

QUESTION: The centripetal force is zero when the centrifugal force is ______.
A. Equal
B. Zero
C. Maximum
D. None of these options are correct
EXPLANATION
Option B is correct since centripetal force and centrifugal force are equal in magnitude and opposite in direction, so it will also be zero. Option A is incorrect since centrifugal force will be equal when centripetal force is equal. Option C is incorrect since centrifugal force will be maximum when centripetal force is maximum. Option D is incorrect since Option B is the right answer.

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 since in a full wave rectifier the frequency of ripple will be double to that of main frequency, so 100Hz. Options B, C, and D are incorrect since they are wrong answers.

QUESTION: The bound state electron have ______.
A. Wave nature
B. Particle nature
C. Dual nature
D. It never moves when in bound state
EXPLANATION
Option C is correct since a bound state is a quantum state of a particle subject to a potential such as its dual nature. Option A is incorrect since all photons or microscopic particles have wave-like properties. Option B is incorrect since an electron is a tiny, negatively charged particle just as if they were waves, not particles. Option D is incorrect since electrons do move in a bound state when they are changing positions.

QUESTION: When white light is passed through cool gases, the spectra we observe is called _____.
A. Line spectra
B. Continuous spectra
C. Absorption line spectra
D. Emission line spectra
EXPLANATION
Option C is correct since absorption line spectra occur when passing white light through cool, thin gas. Option A is incorrect since line spectra is a dark or bright line in an otherwise uniform and continuous spectrum. Option B is incorrect since continuous spectra arise from dense gases or solid objects which radiate heat. Option D is incorrect since emission line spectra are a range of frequencies of electromagnetic radiation.

QUESTION: The control rods in nuclear reactor controls the reaction by _____.
A. Reducing the neutron speed
B. Increasing the neutrons speed
EXPLANATION
Option A is correct since the neutron speed is reduced so that more neutrons are being absorbed by moving down into the reactor. Option B is incorrect since when the neutrons are increased, fear neutrons will be absorbed. Options C and D are incorrect since the reaction is controlled by neutrons of the control rods.

QUESTION:

The length and radius of an electric resistance of a certain wire are doubled simultaneously, then the _____.

A.

Resistance will be doubled and specific resistance will be halved

EXPLANATION

Option B is correct since we know that, R = pl / A = pl / πr²

R’ = p2l / / π(2r²) = R / 2

Specific resistance will remain the same as it is a material property but remember it depends on temperature.

Options A and C are incorrect since specific heat will remain the same.

Option D is incorrect since resistance will be halved.

QUESTION: Calculate the charge passing through the circuit if its current is 10 Ampere and the recorded time is 15 seconds:
A. 1,500 Coulombs
B. 150 Coulombs
C. 13,400 Coulombs
D. 140 Coulombs
EXPLANATION
Option B is correct since after applying the charge formula which is, Q = IT Q = 10 x 15 = 150 Columbs. Options A, C, and D are incorrect since the given options are wrong.

QUESTION: Which principle is used in solar cells?
A. Momentum
B. Charge
C. Mass
D. All of these options are correct
EXPLANATION
Solar cells are photovoltaic cells that convert light energy into direct current (DC). Solar cells have p-type and n-type layers with laminated silicone crystals. When light strikes the crystals, momentum is produced, which generates electricity.

QUESTION: The wavelength of beta rays is measured by:
A. Interference
B. Polarization
C. Absorption
D. Diffraction
EXPLANATION
Diffraction is the process in which a beam of light can be split into shorter wavelengths, thus making it possible to measure them. The wavelength of beta rays can thus be measured by the process of diffraction.

QUESTION: Statements: 1. The management of hospitals is getting worse day by day. 2. The doctors are so confused and they dont even know how to tackle a bunch of patients. Courses of action: I. Our government should increase medical seats. So that we can get more doctors every year. In this case, the stress on medical staff will increase as well. II. The government should provide and develop strategies for medical staff and hospitals.
A. Both of the conclusions follow
B. None of the conclusions follow
C. Only conclusion I follows
D. Only conclusion II follows
EXPLANATION
In the given statement, two major issues are highlighted: 1. Poor management 2. Stress on doctors to handle a high number of patients Course 1 satisfies the second issue; Increasing the number of doctors would allow them to handle and cater to multiple patients. Course 2 satisfies the first issue of management; These strategies would allow the staff to better manage the hospital.

QUESTION: Complete the series: 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: Dependent /Independent causes: Statement I: There is an unprecedented increase in the number of young unemployed in comparison to the previous year. Statement II: A large number of candidates submitted applications against an advertisement for the post of manager issued by a bank.
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
An increase in the number of unemployed youth is bound to draw in huge crowds for a single vacancy.

QUESTION: Fact-Checking: Fact l: All drink mixes are beverages. Fact 2: All beverages are drinkable. Fact 3: All beverages are red. If the above three statements are facts then which of the following statement will also be a fact? I. Some drink mixes are red. II. All beverages are drink mixes. Ill. All red drink mixes are drinkable.
A. I only
B. II only
C. III only
D. None of them is a fact
EXPLANATION
Drink mixes may or may not be red, so option I is not a fact. All drink mixes are beverages but beverages can also be other than drink mixes, option II is also not a fact. Because all drink mixes are beverages and all beverages are drinkable, therefore all red drink mixes will be drinkable. Option III is a fact.

QUESTION: Statements and Actions: Statement: The Management of School Mangna has decided to give free breakfast from next academic year to all the students in its primary section through its canteen even though they will not get any government grant. Courses of Action: (I) The school will have to admit many poor students who will seek admission for the next academic year. (ll)The canteen facilities and utensils have to be checked and new purchases to be made to equip it properly. (Ill) Funds will have to be raised to support the scheme for years to come.
A. Only II and Ill follows
B. Only I and III follows
C. Only I and II follows
D. Only I follows
EXPLANATION
Since the school has introduced the scheme without receiving any grant, it needs to pool up the funds and make adequate arrangements to keep the scheme going. So, only II and III follow.

QUESTION: Statements and Conclusions: All benches are chairs. Some chairs are roads. All roads are pillars. Conclusions: I - Some pillars are benches. II - Some pillars are chairs. Ill -Some roads are benches. IV - No pillar is a bench.
A. None follows
B. Only either I or IV, and III follow
C. Only either I or IV follow
D. Only either I or IV, and II follow
EXPLANATION
I. Some pillars are benches. All benches are desks and Some desks are roads. All roads are pillars. So some pillars are desks, but may not be pillars. II. Some pillars are desks. True, Some desks are roads. All roads are pillars. So some pillars are desks.III. Some roads are benches. False, some roads are desks and some desks are benches, but roads may not be benches. IV. No pillar is a bench. All benches are desks and Some desks are roads. All roads are pillars. So some pillars are desks, but may not be pillars.

QUESTION: Dependent/Independent causes: I. There are orders by the high court to clean Karachi. II. More than 500 people died in Karachi due to land pollution.
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 the effects of an independent cause
EXPLANATION
High land pollution levels killed people in Karachi and due to that the issue was taken to the high court which passed an order to clean the city.

QUESTION: Here are some words translated from an artificial language. dionot means oak tree, blyonot means oak leaf, blycrin means maple leaf. Which word could mean maple syrup?
A. Blymuth
B. Hupponot
C. Patricin
D. Crinweel
EXPLANATION
From the information, we can conclude that Not = oak Dio = tree Blyo/bly = leaf Crin = syrup. So for maple syrup, the word should end with crin and we only have one option for that which is patricin.

QUESTION:

Directions to solve:

In the following question, a statement is given. Followed by two conclusions.

Statement: Without reforming the entire administrative system, we cannot eradicate corruption and prejudice from society.

Assumptions:

I. The existence of corruption and prejudice is good.

II. There is enough flexibility to change the administrative system.

A.

Only assumption I is implicit

EXPLANATION

The statement talks of eradicating corruption and prejudice from society, which indicates that these aspects are undesirable. So, I is not implicit. Besides, the statement mentions reforming the administrative system. So, II is implicit.

QUESTION: The high school math department needs to appoint a new chairperson, which will be based on seniority. Ms. West has less seniority than Mr. Temple, but more than Ms. Brody. Mr. Rhodes has more seniority than Ms. West, but less than Mr. Temple. Mr. Temple doesnt want the job. Who will be the new math department chairperson?
A. Mr. Rhodes
B. Mr. Temple
C. Mr. West
D. Mr. Brody
EXPLANATION
Mr. Temple has the most seniority, but he does not want the job. Next in line is Mr. Rhodes, who has more seniority than Ms. West or Ms. Brody.

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PMC Paid Practice Tests Series 2021 With Explanation - Test 34

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