PMC Paid Practice Tests Series 2021 With Explanation - Test 6

[Shahid]

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: Choose the correct spelling of the word.
A. Fual
B. Fuel
C. Fule
D. Fuil
EXPLANATION
Fuel is the correct spelling.

QUESTION: I _____ him for a long time.
A. Know
B. Have known
C. Am knowing
D. Knew
EXPLANATION
Present perfect have known is exactly the right tense to express something continuing from the past up to the present moment.

QUESTION: _________ ink in my pen is red
A. A
B. An
C. The
D. No article
EXPLANATION
The will be used as the specific ink in the pen is being talked about, and not any random, general ink.

QUESTION: Our neighbours have _____ cat and _____ dog.
A. A...an
B. A...a
C. A....the
D. An....an
EXPLANATION
A/an and the are articles. They are a type of determiner and they go before a noun. Use “a” before words that start with a consonant sound and “an” before words that start with a vowel sound.

QUESTION: Most big cities have ______ university.
A. A
B. An
C. The
D. No article
EXPLANATION
A/an and the are articles. They are a type of determiner and they go before a noun. Use “a” before words that start with a consonant sound and “an” before words that start with a vowel sound. No specific university is being talked about.

QUESTION: Choose the correct spelling of the word
A. Anothar
B. Another
C. Anuther
D. Anothere
EXPLANATION
Another is used to refer to an additional person or thing of the same type as one already mentioned or known about; one more; a further.

QUESTION: The _______ chosen for the construction of the building is in the heart of the city.
A. Cite
B. Slight
C. Sight
D. Site
EXPLANATION
A site is a chosen area of ground on which a town, building, or monument is constructed.

QUESTION: My brother and sister ______ basketball every evening.
A. Practices
B. Practice
C. Practicing
D. Are practicing
EXPLANATION
Since more than one person is being talked about, practice will be used.

QUESTION: What is the tone of this sentence: Please be seated
A. Declarative
B. Imperative
C. Interrogative
D. Exclamatory
EXPLANATION
An imperative sentence is a command or request.

QUESTION: Should have
A. Shouldhve
B. Shouldve
C. Shouldve
D. Shouldave
EXPLANATION
A contraction is a shortened form of a word (or group of words) that omits certain letters or sounds. In most contractions, an apostrophe represents the missing letters.

QUESTION: The ebb and flow of the tides _________ explained by Newton.
A. Are
B. Was
C. Were
D. Is
EXPLANATION
Was is a past tense indicative form of be, meaning “to exist or live,” and is used in the first person singular (I) and the third person singular (he/she/it). You use the past indicative when youre talking about reality and known facts.

QUESTION: What is the tense of this question? Will Tom be able to mend that broken window?
A. Present
B. Past
C. Future
D. None of these
EXPLANATION
The word will indicates future tense.

QUESTION: Jack is six years old, but he ________ French and Spanish.
A. Speaking
B. Is speaking
C. Speaks
D. Speak
EXPLANATION
Since he can speak more than one language, speaks will be used.

QUESTION: The information provided to you _________ wrong.
A. Were
B. Was
C. Are
D. Have been
EXPLANATION
Was is a past tense indicative form of be, meaning “to exist or live,” and is used in the first person singular (I) and the third person singular (he/she/it). You use the past indicative when youre talking about reality and known facts.

QUESTION: Juxtaposition
A. Contrast
B. Wit
C. Image
D. Freedom
EXPLANATION
Juxtaposition is the fact of two things being seen or placed close together with a contrasting effect. Thus, contrast is a suitable synonym.

QUESTION: Find an error in the following sentence.
A. We are trying
B. To locate the
C. Historical city for
D. The past two years.
EXPLANATION
Instead of we are trying, we should use we have been trying as this event indicates something happening in the past.

QUESTION: Sentiment
A. Practical
B. Emotion
C. Dispassionate
D. Realistic
EXPLANATION
Invent means to create something that did not exist before so it makes sense that the genius of mankind is being mentioned.

QUESTION: It needed the collective genius of mankind to _________ the wheel.
A. Discover
B. Find
C. Perform
D. Invent
EXPLANATION
The wheel was invented.

QUESTION: Choose the correct spelling of the word
A. Possesion
B. Possession
C. Posesion
D. Posession
EXPLANATION
Possession is the state of having, owning, or controlling something. [FACT]

QUESTION: _______ man is mortal.
A. A
B. An
C. The
D. No article
EXPLANATION
In general, no article is used with proper nouns, mass nouns where the reference is indefinite, or plural count nouns where the reference is indefinite.

QUESTION: The outermost layer in a typical plant cell would be _______ .
A. Primary cell wall
B. Secondary cell wall
C. Middle lamellae
D. Cell surface membrane
EXPLANATION
Factual recall

QUESTION: Which of the following pigments is Blue-green in colour?
A. Chlorophyll a
B. Chlorophyll b
C. Chlorophyll c
D. None of these
EXPLANATION
Chlorophyll a: a blue-green pigment. Chlorophyll b: a yellow-green pigment. Chlorophyll c: a green pigment.

QUESTION: Cartilage is a form of:
A. Cardiac tissue
B. Connective tissue
C. Epithelial tissue
D. Nervous tissue
EXPLANATION
Cardiac tissue is a specialized tissue that forms the heart only. Connective tissue is the tissue that connects or separates and supports all other types of tissues. The epithelium is a type of body tissue that forms the covering on all internal and external surfaces of your body, lines body cavities and hollow organs and is the major tissue in glands. Nervous tissue is found in the brain, spinal cord, and nerves. The cartilage is a tissue that supports and gives structural rigidity and also connects other tissues so the answer is B, a connective tissue.

QUESTION: What is the function of the fluid secreted by sertoli cells?
A. Provides liquid medium
B. Provides protection to sperms
C. Provides nourishment to sperms
D. All A, B and C are correct
EXPLANATION
Sertoli cells are responsible for the formation and secretion of seminiferous tubule fluid (STF) which provides the nutritional environment necessary for spermatogenesis and provides a liquid medium for transport. All the options are correct hence the answer is D.

QUESTION: Monosynaptic reflex arc consists of:
A. One sensory neuron only
B. One motor neuron only
C. Two neurons, One sensory neuron, and one motor neuron
D. None of these
EXPLANATION
When a reflex arc consists of only two neurons, one sensory neuron, and one motor neuron, it is defined as monosynaptic. Monosynaptic refers to the presence of a single chemical synapse.

QUESTION: Breathing rate in humans at rest is:
A. 10 to 15 times per minute
B. 10 to 20 times per minute
C. 80 to 120 times per minute
D. 15 to 20 times per minute
EXPLANATION
The respiration rate is the number of breaths a person takes per minute which is about 15-20 in a human at rest.

QUESTION: Population growth is checked by which of the following?
A. No competition
B. No polymarphism
C. Polymorphism
D. Competition
EXPLANATION
When two species share overlapping ecological niches, they may be forced into competition for the resources of that niche. This interspecific competition is a way to check on the growth of one or both populations hence the answer is D.

QUESTION: Reactions in which simple substances are combined to form complex substances are called
A. Metabolic reactions
B. Catabolic reactions
C. Anabolic reactions
D. None of these
EXPLANATION
Catabolic reactions break large molecules into smaller molecules. Anabolism and catabolism are the two broad types of biochemical reactions that make up metabolism. Anabolic reactions build up complex substances from simpler substances so the answer is C.

QUESTION: Chromosomes that have different alleles of a given gene at locus is called?
A. Homozygous
B. X chromosomes
C. Y chromosomes
D. Heterozygous
EXPLANATION
Chromosomes with the same alleles are called homozygous. X and Y are sex chromosomes which determine the sex of the child. Heterozygous chromosomes have different alleles so the answer is D.

QUESTION: In what year was the first person vaccinated by Edward Jenner?
A. 1876
B. 1796
C. 1696
D. 1850
EXPLANATION
Edward Jenner inoculated a boy with the cowpox virus in 1796.

QUESTION: The genetic change in a population caused by natural selection is called?
A. Polymorphism
B. Specialization
C. Gene linkage
D. Adaptation
EXPLANATION
Natural selection is a mechanism in which organisms that are better adapted, survive and pass on those genes which aided their success. Since D mentions adaptation, that is the correct option.

QUESTION: The large number of bundle fibers that joins the left and right cerebral hemispheres is called?
A. Brocas area
B. Lateral sulcus
C. Corpus callosum
D. Thalamus
EXPLANATION
The corpus callosum (option C) is a large bundle of more than 200 million myelinated nerve fibers that connect the two brain hemispheres, permitting communication between the right and left sides of the brain.

QUESTION: What is a Provirus?
A. Free virus
B. Free DNA
C. Primitive virus
D. Integrated viral genome
EXPLANATION
Provirus is a form of a virus that is integrated into the genetic material of a host cell and by replicating with it can be transmitted from one cell generation to the next without causing lysis hence it is D.

QUESTION: Centrioles are composed of how many triplets of microtubules?
A. 6
B. 9
C. 12
D. 15
EXPLANATION
There are 9 triplets of microtubules.

QUESTION: In acidic medium, amino acids carry positive charge and act as:
A. Acid
B. Base
C. Neutral
D. None of these options are correct
EXPLANATION
In acidic conditions, the amino acid acts as a base and accepts a proton at the amino group. In alkaline conditions, the amino acid acts as an acid and donates a proton from its carboxyl group. Hence the answer is B.

QUESTION: A Dutch scientist firstly observed very small creatures in
A. Vinegar
B. Saliva
C. Rain water
D. All of Above
EXPLANATION
A Dutch Scientist A.V. Leeuwenhoek discovered bacteria in rainwater.

QUESTION: What is the origin of the acoelomate gut?
A. Ectodermal
B. Mesodermal
C. Endodermal
D. None of these
EXPLANATION
The endoderm gives rise to the lining of the esophagus, stomach, and intestines, as well as associated organs.

QUESTION: The umbilical cord contains which of the following:
A. Pluripotent stem cells
B. Blood stem cells
C. Cord blood stem cells
D. Both Options A and B are correct
EXPLANATION
Oxygen and nutrients from the mothers blood are transferred across the placenta to the fetus through the umbilical cord. This enriched blood flows through the umbilical vein toward the babys liver. Umbilical cord blood contains blood-forming stem cells, which can renew themselves and differentiate into other types of cells. Stem cells are used in transplants for patients with cancers like leukemia and lymphoma. Cord Blood can be used to treat over 80 other life-threatening diseases.

QUESTION: Mantle in molluscs is present over which of the following regions?
A. Head
B. Dorsal muscular foot
C. Dorsal visceral foot
D. Both A and B
EXPLANATION
A loose mantle is present over the body in Molluscs. It is a significant part of the body of molluscs. It is the dorsal body wall that covers the visceral mass of Molluscs. It secretes calcium carbonate and conchiolin. This results in the formation of a shell.

QUESTION: What is the viral nucleocapsid made up of?
A. Genome and capsid
B. Capsid and spikes
C. Envelope and capsid
D. Capsomere and genome
EXPLANATION
Viral nucleocapsid consists of the genome and is usually composed of protein subunits called capsomeres so the answer is D.

QUESTION: The resting potential membrane is determined by which of the following?
A. Potassium ion gradient
B. Sodium ion gradient
C. Bicarbonate ion gradient
D. None of these
EXPLANATION
The resting membrane potential is a result of different concentrations inside and outside the cell. The difference in the number of positively charged potassium ions (K+) inside and outside the cell dominates the resting membrane potential hence the answer is A.

QUESTION: A hydrostatic skeleton is present in _________ .
A. Arthropods
B. Fishes
C. Annelids
D. Nematodes
EXPLANATION
A hydrostatic skeleton is a skeleton formed by a fluid-filled compartment within the body, called the coelom used by animals for movement and support.it is found inside annelids so the answer is C.

QUESTION: What type of viruses are the polioviruses?
A. DNA enveloped virus
B. RNA enveloped virus
C. DNA naked virus
D. RNA naked virus
EXPLANATION
Poliovirus, of the family Picornaviridae, is a non-enveloped single-stranded positive-sense RNA virus.

QUESTION: In which organism males are haploid?
A. Aphids
B. Mosquito
C. Butterfly
D. Honey bee
EXPLANATION
In the Hymenoptera (bees, ants, and wasps), males are haploid, meaning they have no father; their single set of chromosomes comes from their mother. So the answer is D.

QUESTION: Who developed a theory of natural selection essentially identical to Darwins?
A. Hardy-Weinberg
B. Malthus
C. Lamark
D. Alfred Wallace
EXPLANATION
The Hardy-Weinberg equilibrium is a principle stating that the genetic variation in a population will remain constant from one generation to the next in the absence of disturbing factors. Lamarckism is a theory of evolution based on the principle that physical changes in organisms during their lifetime—such as greater development of an organ or a part through increased use—could be transmitted to their offspring. Alfred Russel Wallace was a naturalist who independently proposed the theory of evolution by natural selection so the answer is D.

QUESTION: When is sugar formed in photosynthesis?
A. light independent reaction
B. light dependent reaction
C. Both a and b
D. None of these
EXPLANATION
Sugar is formed during the Calvin cycle which is a light independent reaction.

QUESTION: The ultimate source of all the change is?
A. Migration
B. Mutation
C. Genetic drift
D. Selection
EXPLANATION
The ultimate source of all genetic variation is mutation. The mutation is important as the first step of evolution because it creates a new DNA sequence for a particular gene, creating a new allele.

QUESTION: Visible genetic traits include which of the following?
A. Hair color
B. Eye color
C. Number of limbs
D. All of these
EXPLANATION
Hair color, eye color, and the number limbs are all phenotypes meaning they are physical features that can be seen with a naked eye.

QUESTION: _______ is a competitive inhibitor of succinic dehydrogenase.
A. Malonic acid
B. Malic acid
C. Fumaric acid
D. Acetic acid
EXPLANATION
Malonate is a reversible inhibitor of succinate dehydrogenase.

QUESTION: An activated enzyme consisting of polypeptide chain and a cofactor is called?
A. Apoenzyme
B. Holoenzyme
C. Activated enzyme
D. Both B and C
EXPLANATION
Apoenzyme is the inactive form of the enzyme that activates upon the binding of a cofactor. An apoenzyme itself is unable to catalyze a reaction without a cofactor. Only the combination of apoenzymes along with the cofactor produces the catalytically-active enzyme. Holoenzyme refers to the apoenzyme along with the cofactor that is complete and catalytically active. A cofactor can be either a metal ion or a small organic molecule so the answer is B.

QUESTION: Cell wall is only absent in the following group of bacteria;
A. Staphylococci
B. Pseudomunas
C. Diplococcus pneumonia
D. Mycoplasmas
EXPLANATION
The answer is D because Mycoplasma is an important cause of disease in animals and is not affected by antibiotic treatments that target cell wall synthesis. Mycoplasma acquires cholesterol from the environment and form sterols to build their cytoplasmic membrane.

QUESTION: A researcher is studying a population of insects and notices that 60% have red eyes, 30% have apricot eyes, 5% have white eyes, and 5% have pink eyes. Which of these eye colors would be designated the wild type?
A. Red
B. White
C. Pink
D. All of these
EXPLANATION
The wild type is the phenotype of the typical form of a species as it occurs in nature which in this case is red since it is the highest percentage.

QUESTION: Calcium, during muscle contraction binds with?
A. Tropomyosin
B. Troponin C
C. Troponin I
D. Troponin T
EXPLANATION
Calcium binds to troponin C, causing the conformational shift in tropomyosin that reveals myosin-binding sites on actin. Troponin C is the calcium binding site of calcium on tropnin.

QUESTION: What are the distinguishing features of fibrous proteins?
A. Non-crystalline
B. Elastic
C. Disorganized
D. Both A and B
EXPLANATION
Fibrous proteins are made up of polypeptide chains that are elongated and fibrous in nature or have a sheet-like structure. They are also non crystalline and elastic hence the answer is both A and B.

QUESTION: Who was the first to propose an objective definition of instincts in terms of animal behaviour?
A. Wallace
B. Lamark
C. Lyell
D. Darwin
EXPLANATION
Darwin proposed the first objective of instincts and said that instinctive behavior in animals could be explained using the resources of his theory, such behavior essentially being no different than other adaptations.

QUESTION: A muscular passage that is common to both food and air is known as
A. Bronchi
B. Bronchioles
C. Larynx
D. Pharynx
EXPLANATION
The pharynx, commonly called the throat, is a muscular, funnel-shaped passageway inside the body. It connects the mouth and nose to the esophagus (leading to the stomach) and larynx (leading to the trachea and then the lungs).

QUESTION: Photosystem 2 absorbs maximum wavelenght of light?
A. 750
B. 650
C. 680
D. 670
EXPLANATION
Photosystem I absorbs sunlight at a wavelength of about 700 nm while Photosystem II absorbs sunlight at a wavelength of 680 nm in the red region so the answer is C.

QUESTION: The response of the sympathetic nervous system is known as which of the following?
A. Autonomic response
B. Flight response
C. Somatic response
D. Reflex response
EXPLANATION
The sympathetic nervous system directs the bodys rapid involuntary response to dangerous or stressful situations. A flash flood of hormones boosts the bodys alertness and heart rate, sending extra blood to the muscles. This is known as the flight response so the answer is B.

QUESTION: SIV is the abbreviation of
A. Simian imunodeficiency virus
B. Silurian imunodeficiency virus
C. Siberian imunodeficiency virus
D. Both A and C
EXPLANATION
SIV stands for Simian immunodeficiency virus.

QUESTION: According to the fluid mosaic model, the plasma membrane is composed of which of the following?
A. Phospholipid
B. Extrinsic proteins
C. Intrinsic proteins
D. All of these
EXPLANATION
fact

QUESTION: How many molecules of carbon dioxide enter the Calvin cycle to produce one molecule of carbohydrate?
A. 2
B. 3
C. 4
D. 1
EXPLANATION
The fixation of three carbon dioxide molecules allows one net G3P molecule to be produced (that is, allows one G3P molecule to leave the cycle).

QUESTION: The 23rd pair of chromosomes in man is
A. Polymorphic
B. Heteromorphic
C. Homomorphic
D. Automorphic
EXPLANATION
The 23rd pair of chromosomes are the sex chromosomes which are heteromorhpic because it is a chromosome pair with same homology but differing in size, shape, or staining properties. So the answer is B.

QUESTION: High fever, cold, and cough with sputum production are symptoms of
A. Emphysema
B. Asthma
C. Pneumonia
D. Bronchitis
EXPLANATION
Productive cough and fever are usually the presenting symptoms in patients with pneumonia. A classic sign of bacterial pneumonia is a cough that produces thick, blood-tinged or yellowish-greenish sputum with pus.

QUESTION: This is an example of glycoprotein
A. Starch
B. Haemoglobin
C. Lecithin
D. Mucin
EXPLANATION
Starch is made up of carbohydrates. Hemoglobinis a quaternary structure protein. Lecithin is a phospholipid and mucin is a glycoprotein hence the answer is D.

QUESTION: The thick and thin filaments of myofibrils are arranged in units called:
A. Z-line
B. Aactin
C. Sarcomere
D. Sarcolemma
EXPLANATION
The thick and the thin filaments make up the sarcomere so option C is correct. The sarcolemma is the plasma membrane of the muscle cell.

QUESTION: ATP is used when _____
A. To synthesize the macromolecules
B. To transport molecules and ions
C. To perform mechanical work
D. All of the above
EXPLANATION
ATP is needed for active transport which is the transport of ions and molecules and movement which is mechanical work. ATP is also used for energy-releasing reactions (food breakdown) and energy-requiring reactions (synthesis). Since options A, B, and C mention these functions, option D is correct.

QUESTION: The rise in blood glucose concentration occurs due to which hormone?
A. Glucagon
B. Glucose
C. Insulin
D. All of these
EXPLANATION
Insulin is the hormone that brings the blood glucose level down to the normal concentration when it is too high. Whereas Glucagon increases the blood glucose when it is too low so the correct answer is A.

QUESTION: A group of populations that have the potential to interbreed in nature is known as which of the following?
A. Genus
B. Family
C. Specie
D. Community
EXPLANATION
Species is a group of organisms that can reproduce with one another in nature and produce fertile offspring.

QUESTION: Animal cells are interconnected by which of the following?
A. Plasma membrane
B. Cell wall
C. Desmosomes
D. Plasmodesmata
EXPLANATION
Animal cells do not possess a cell wall or plasmodesmata. A plasma membrane is a cell membrane. A desmosome is a structure by which two adjacent cells are attached so the correct option is C.

QUESTION: The part of chlorophyll molecule is embedded in the core of thylakoid membrane which is?
A. Hydrophilic
B. Hydrophobic
C. Both of these
D. None of these
EXPLANATION
A chlorophyll molecule has a hydrophobic tail that embeds the molecule into the thylakoid membrane.

QUESTION: What is reduced in photosynthesis?
A. Oxygen
B. Carbon dioxide
C. Water
D. Light
EXPLANATION
CO2 gets reduced during the calvin cycle.

QUESTION: Whats the difference between homologous and analogous structures?
A. Homologous structures result from a common ancestor; analogous structures result from repetitive usage by the individual
B. Homologous structures result from convergent evolution; analogous structures result from a common ancestor
C. There is no difference between homologous and analogous structures
D. Homologous structures result from a common ancestor; analogous structures result from convergent evolution
EXPLANATION
Homologous organs have similar basic structures and a common origin but they perform different functions. Analogous organs are different in structure and origin but perform similar functions(convergent evolution) hence the answer is D.

QUESTION: Storage form of lipids is
A. Esterified cholesterol
B. Glycerophospholipids
C. Triglycerides
D. Sphingolipids
EXPLANATION
The main storage form of lipids is triglycerides.

QUESTION: Which of the following is an ovoviviparous animal?
A. Basking shark
B. Humans
C. Blue shark
D. All of these
EXPLANATION
Ovoviviparous animals lay eggs and develop the eggs inside the mothers body. Humans and blue sharks are viviparous meaning that fertilization and embryo development happen inside the body which leaves option A, basking shark which is the correct answer.

QUESTION: A defective virus that needs the unrelated help of virus that infects the same host cell in order to provide essential functions?
A. Satellite virus
B. HAV
C. HCV
D. HIV
EXPLANATION
Satellite viruses are a group of viruses encoding structural components of their virions, but incapable of completing the infection cycle without the assistance of a helper virus.

QUESTION: Which is not the characteristic of triploblastic?
A. They may be coelomate pseudocoelomate or acoelomate
B. They are included in grade bilateria
C. All of them have a digestive system
D. All of them have blood vascular system
EXPLANATION
All triploblastic animals are bilateral and have a gut cavity. Triploblastic animals can be further divided into these categories: Acoelomates, eucoelomates, and pseudocoelomates. There are two internal circulatory systems: coelomic and blood vascular. Most triploblastic animals possess both a coelomic circulatory system and a blood vascular system. So the answer is D since the options are characteristics of triploblastic organisms.

QUESTION: The envelope of an enveloped virus is derived from?
A. The mitochondrion of the cell
B. Cell membrane of host cell
C. Endoplasmic reticulum of the cell
D. None of these
EXPLANATION
The envelopes are typically derived from portions of the host cell membranes (phospholipids and proteins), but include some viral glycoproteins.

QUESTION: The end product of an enzymatic reaction inhibits formation of product in an earlier step. This type of enzymatic regulation is known as?
A. Allosteric regulation
B. Negative regulation
C. Metabolic pathway loop
D. Feedback inhibition
EXPLANATION
Feedback inhibition is the inhibition of an enzyme, controlling an early stage of a series of biochemical reactions, by the end product when it reaches a critical concentration.

QUESTION: The process of self-digestion of selective nonfunctional organelle by cells through the actions of enzymes originating from the cell is called?
A. Pinocytosis
B. Endocytosis
C. Autophagy
D. Cytotoxicity
EXPLANATION
Pinocytosis is a process by which liquid droplets are ingested by living cells. Endocytosis is a general process by which cells engulf external substances by gathering them into vesicles. Cytotoxicity is a substance that kills cells, including cancer cells. “Auto” means self and “phagy” means eat. So the literal meaning of autophagy is “self-eating.” which is why C is correct.

QUESTION: The composition of the white matter of spinal cord is ______.
A. Myelinated dendrite
B. Non-myelinated dendrite
C. Non-myelinated axon
D. Myelinated axon
EXPLANATION
White matter contains nerve fibers (axons), which are extensions of nerve cells (neurons). Many of these nerve fibers are surrounded by a type of sheath or covering called myelin.

QUESTION: The stomata arc closes at which of the following temperature? (In centigrade)
A. 45
B. 35
C. 15
D. 25
EXPLANATION
The stomata would close at higher temperatures to prevent excess evaporation of water and since the highest temperature in the options is 45 that is the correct answer.

QUESTION: What contributes to genetic variation during human reproduction?
A. Random mating
B. Nonrandom mating
C. Independent assortment
D. All of these
EXPLANATION
Nonrandom mating can also be outbreeding, wherein there is an increased probability that individuals with a particular genotype will mate with individuals of another particular genotype. Random mating increases the chances of genetic variation. Independent assortment during meiosis is the random assortment of chromosomes and so new combinations are made. All three options cause genetic variation hence the answer is D, all of them.

QUESTION: Which of the following best describes the impact of purifying selection?
A. It increases frequency of an allele.
B. It is the same as disruptive selection.
C. It increases genetic diversity.
D. It removes variation from the population.
EXPLANATION
Negative selection or purifying selection is the selective removal of alleles that are harmful.

QUESTION: Which of the following characters is not typical to class Mammalia?
A. Alveolar lungs
B. Seven cevical vertebrae
C. Thecodont dentition
D. Ten pairs of cranial nerves
EXPLANATION
In higher vertebrates (reptiles, birds, mammals) there are 12 pairs of cranial nerves.

QUESTION: What is the approximate diameter of the peroxisome?
A. 0.5 micrometer
B. 1.5 micrometer
EXPLANATION
The average size of peroxisomes is 0.5 micrometers.

QUESTION: The follicle celIs, after release of the egg, are modified to form a special strcture called:
A. Endometrium
B. Perimetrium
C. Corpus luteum
D. None of these options are correct
EXPLANATION
When an ovarian follicle releases an egg during the ovulatory phase, the opened follicle closes off, forming what is called the corpus luteum. The corpus luteum is responsible for producing the hormone progesterone, which stimulates the uterus to thicken even more in preparation for implantation of a fertilized egg.

QUESTION: Which one is responsible for opening and closing of stomata?
A. Rise in pH of guard cells causes hydrolysis of starch.
B. Cytokinins and cAMP are required.
C. Absicisic acid promotes closure.
D. All of the above.
EXPLANATION
When there is a rise in pH it causes hydrolysis of starch into sugar which accumulates in guard cells, resulting in the opening of cells. For this mechanism, cytokinins and cAMP are required. Abscisic acid is the stress hormone that results in the closing of stomata. So, the correct answer is All of the above.

QUESTION: Which of these functions will be affected if the medulla oblongata is damaged?
A. Thermoregulation
B. Vision
C. Memory
D. Tactile sensation-response when pricked with a needle.
EXPLANATION
The medulla oblongata plays a vital role in regulating involuntary processes such as breathing, heart rate, and reflex responses. It gives rise to many of the cranial nerves, hence the answer will be D.

QUESTION: In Charless Law, volume of gas is directly related to which factor?
A. Pressure
B. Temperature
C. Volume
D. Number of moles
EXPLANATION
Charless law states the volume of a gas is directly proportional to its temperature when the values of gas and pressure stay constant. V1/T2 = V2/T2

QUESTION: The e/m value is maximum for _____ gas because of _____ value of m for positive rays obtained from it.
A. Oxygen gas, lowest
B. Hydrogen gas, highest
C. Hydrogen gas, lowest
D. Helium gas, highest
EXPLANATION
Anode rays consist of positively charged ions obtained by the removal of one or more electrons from neutral gaseous atoms. Among the given gases, hydrogen has the least mass (lowest value of m) so it has a maximum value of e/m.

QUESTION: Which type of movement is shown by the atoms of the solid?
A. Translational motion
B. Vibrational motion
C. Rotational motion
D. Linear motion
EXPLANATION
In a solid, the atoms have strong attractions for each other so they vibrate in fixed positions.

QUESTION: Following are examples of Intramolecular forces except?
A. Ionic bond
B. Covalent bond
C. Metallic bond
D. Dipole Dipole forces
EXPLANATION
Dipole-dipole forces are attractive forces between molecules.

QUESTION: High molecular mass organic compounds, upon hydrolysis yield amino acids are called _____.
A. Carbohydrates
B. Lipids
C. Proteins
D. DNA
EXPLANATION
High molecular mass organic compounds that upon hydrolysis yield amino acids are called proteins. Proteins are made up of amino acids and are decomposed into amino acids during protein hydrolysis.

QUESTION: Nitrogen N2 molecule has 3 unpaired electron on each atom therefore it shows three bond that are ?
A. 2 sigma & 1 pi bond
B. 1 sigma & 2 pi bond
C. 3 sigma
D. 3 pi bond
EXPLANATION
In a nitrogen molecule, the two nitrogen atoms are bonded by a triple covalent bond. The first formed bond is a sigma bond while the other two are pi bonds.

QUESTION: Two compartments of a galvanic cell are connected by :
A. A battery
B. Electrical Wires
C. A pipe
D. Salt Bridge
EXPLANATION
A salt bridge is a device used to connect the oxidation and reduction half-cells of a galvanic cell.

QUESTION: Which of the following is an example of free radical?
A. Br+
B. Br-
C. Br
D. Cl2
EXPLANATION
Bromine exists in diatomic form. A Free Radical can be recognized by a single atom, having a neutral charge, when it should be binded to form a molecule. In this case, Br shouldnt exist unless it is a free radical.

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
Fact.

QUESTION: Buffer solutions resist change in their?
A. Temperature
B. Solubility
C. Volatility
D. pH
EXPLANATION
A buffer solution is an aqueous solution that resists changes in pH upon the addition of an acid or a base.

QUESTION: The slope of the curve obtained by plotting concentration change with time is actually
A. Reaction time
B. Reaction Speed
C. Rate of reaction
D. All of these
EXPLANATION
A plot of the concentration of any reactant versus time graph is a straight line that gives a slope which represents the rate of a chemical reaction, which is defined as the rate of change in concentration of a reactant or product over time.

QUESTION: Which of the following properties are associated with transition metals?
A. Color
B. Complex formation
C. Use as catalyst
D. All of these
EXPLANATION
All of these are properties associated with transition metals.

QUESTION: According to Bohrs theory Electron should move _____ nearer to nucleus in an orbit of _____ radii.
A. Slower, smaller
B. Faster, smaller
C. Faster, bigger
D. Slower, bigger
EXPLANATION
According to Bohrs atomic model, the lower the atoms energy level is, the smaller the electrons orbit will be, meaning a smaller radius. The atom’s energy level is most low when it is closest to the nucleus, meaning that is where the smallest orbit is present. As electrons move farther away from the nucleus, they gain potential energy and become less stable. Atoms with electrons in their lowest energy orbits are in a ground state (furthest from the nucleus), and those with electrons jumped to higher energy orbits are in an excited state (closest to the nucleus). The electrons that are closest to the nucleus, have a smaller radius and more energy thus moving faster.

QUESTION: Which one of the following is a state function that describe both the internal energy and product of pressure and volume?
A. Entropy
B. Heat
C. Enthalpy
D. Temperature
EXPLANATION
Enthalpy is known as internal energy, and the product of pressure and volume in a reaction system.

QUESTION: Which of the following reaction takes place when alkyl halide react with KOH in water?
A. Substitution reaction
B. Elimination reaction
C. Addition reaction
D. None of these
EXPLANATION
A substitution reaction (also known as a single displacement reaction) is a chemical reaction during which one functional group in a chemical compound is replaced by another functional group. ​​In an aqueous solution, KOH is almost completely involved to give an OH- ion which gives a substitution reaction on alkyl halide to form alcohol.

QUESTION: The number of atoms present in a molecule determines its ____.
A. Shape
B. Size
C. Molecularity
D. Atomicity
EXPLANATION
Atomicity is known as the number of atoms in the molecule of an element.

QUESTION: The atoms of hemoglobin are heavier than H-atoms
A. 67,000 times
B. 68,000 times
C. 65,000 times
D. 69,000 times
EXPLANATION
Fact.

QUESTION: To avoid long reaction time and to get equilibrium mixture quickly we add?
A. More reactants
B. Catalyst
C. Inhibitors
D. Enzymes
EXPLANATION
A catalyst is used to speed up a reaction since it lowers the activation energy.

QUESTION: A _____ is the force, which holds together two or more atoms or ions to form a large variety of compounds.
A. Ionic bond
B. Chemical bond
C. Covalent bond
D. Metallic bond
EXPLANATION
By definition, a chemical bond is a string force that holds together two or more atoms in a molecule.

QUESTION: Steam causes more severe burns than boiling water because it has _____.
A. Latent heat of fusion
B. Latent heat of vaporization
C. Latent heat of sublimation
D. All of these
EXPLANATION
Steam has more energy than water at the same temperature. Steam uses latent heat of vaporization to get vaporized, an energy which water doesnt have. Latent heat energy is the cause of more severe burns.

QUESTION: Carboxylic acids turn?
A. Red litmus blue
B. Blue litmus red
C. Neutral to litmus
D. No effect
EXPLANATION
Acids turn blue litmus red and bases turn red litmus blue.

QUESTION: London dispersion forces are the only forces present amongst ?
A. Atoms of helium in gaseous state at high temperature.
B. Molecules of water.
C. Molecules of solid iodine.
D. Molecules of HCl gas.
EXPLANATION
Helium, being a noble gas, exists in monoatomic form. The atoms of helium attract each other via London dispersion forces, and these forces are most apparent in helium. Solid Iodine has its molecules in a fixed space so, the impact of London Dispersion forces is negligible. Molecules of HCl have permanent dipole forces.

QUESTION: What is the other name of 2,4,6-trinitrophenol?
A. Picric acid
B. Nitrophenol
C. TNT
D. Benzophenone
EXPLANATION
The IUPAC name for picric acid is 2,4,6-trinitrophenol.

QUESTION: The first ionization potential of alkaline earth metal is greater than alkali metals because ?
A. They are more reactive.
B. They have greater atomic radii.
C. They have smaller atomic sizes.
D. All
EXPLANATION
The atoms of alkaline earth metals have a smaller radius as compared to the alkali metals, so the electrons in the outermost shells of the alkaline earth metals are more tightly held. The first ionization energies of the elements increase as you go from left to right across a period of the periodic table, so the ionization potential of alkaline earth metals is higher than those of alkali metals.

QUESTION: Which of the following has lower vapor pressure?
A. Glycerol
B. Isopentane
C. Ethanol
D. Both A and C
EXPLANATION
Vapour Pressure can be understood as the amount of substance, that has transitioned into a gas, in contact with its liquid form, in an isolated chamber.  This would imply that substances, with high boiling points, would have lower vapour pressure, since more of the substance exists as liquid, rather than gas. Hence the stronger the intermolecular forces between molecules the lower the vapour pressure.  Glycerol, having the strongest IMFs has the highest boiling point and thus would have the lowest vapour pressure.

QUESTION: The elements of which group show abnormally very low values of electron affinity in every period of periodic table ?
A. Group 2A
B. Group 5A
C. Both A & B
D. None of these
EXPLANATION
When moving down a group in the periodic table, the radius of atoms gradually increases because of the addition of a valence shell. The nucleus has a weak attraction towards the valence electrons and it gradually becomes weaker to the lower atoms in a particular group.

QUESTION: The shape of crystal in which it usually grows is called its _____.
A. Size
B. Capacity
C. Habit
D. Property
EXPLANATION
Crystal habit is the form exhibited by any crystal that determines its crystal shape.

QUESTION: Dehydration of alcohols at low temperature and high acid concentration results in?
A. Alkene
B. Ether
C. Carboxylic acid
D. Aldehydes
EXPLANATION
Alcohol can be dehydrated to form either alkenes (higher temperature, excess acid) or ethers (lower temperature, excess alcohol).

QUESTION: When we react an active metal like Al with less active element like Cu, it will form ?
A. Dry cell
B. Galvanic cell
C. Electrolytic cell
D. A and B
EXPLANATION
A galvanic cell consists of two different metals (electrodes) connected through a conducting solution (an electrolyte).

QUESTION: Which of the following is not a derivative of carboxylic acid?
A. Alkyl Halide
B. Acetamide
C. Ester
D. Anhydride
EXPLANATION
Alkyl halide cannot be derived from carboxylic acids.

QUESTION: In which direction Cathode rays deflected in the presence of magnetic field?
A. Moves upward
B. Move downward
C. Move randomly
D. Moves in straight line
EXPLANATION
Cathode rays are deflected by a magnetic field. The rays move downward, away from the negatively charged electrical field and towards a positively charged field.

QUESTION: An exothermic reaction is allowed to reach equilibriuim. If heat energy is removed then, the equilibrium will shift ?
A. To the product side.
B. To reactant side.
C. Toward the middle.
D. None of these.
EXPLANATION
In an exothermic reaction, heat leaves the system as a product. In this case, when heat is removed the equilibrium of the reaction will shift to the product side.

QUESTION: Thermal energy is also called as ________?
A. Internal energy
B. Temperature of a body
C. Kinetic energy
D. Heat energy
EXPLANATION
This question has been repeated in multiple other papers, hence indicating that this is a high-yield concept. Heat energy is another term for thermal energy.

QUESTION: NaBH4 causes reduction of aldehyde and ketones into _______?
A. Alcohols
B. Alkenes
C. Phenols
D. Alkanes
EXPLANATION
Aldehydes and ketones are reduced to alcohols with either sodium borohydride NaBH4 or lithium aluminum hydride LiAlH4. NaBH4 is a reagent that transforms aldehydes and ketones to the corresponding alcohol, primary or secondary, respectively.

QUESTION: When an electrophilic reagent attacks on alcohol, ________.
A. O - H bond formed.
B. O - H bond breaks.
C. C - O bond breaks.
D. Rise in boiling point.
EXPLANATION
The attack of a nucleophile on an alcohol breaks the C-O bond, whereas the attack of an electrophile breaks the O-H bond. Electrophiles form a bond with the lone pair of oxygen.

QUESTION: Compounds having benzene ring are called as _____?
A. Alicyclic
B. Aliphatic compounds
C. Aromatic compounds
D. Acyclic compounds
EXPLANATION
An aromatic compound is an organic compound that contains a benzene ring or other ring in which the bonding is like that of benzene. Another name for an aromatic compound is an arene.

QUESTION: The reaction in Galvanic Cell is :
A. Spontaneous
B. Nonspontaneous
C. Irreversible
D. Endothermic
EXPLANATION
Galvanic cells are electrochemical cells in which spontaneous oxidation-reduction reactions produce electrical energy.

QUESTION: Structure of ice is similar to which of the following?
A. Liquid water
B. Diamond
C. Graphite
D. Sucrose
EXPLANATION
The crystal structure of a diamond is a face-centered cubic (FCC lattice). Each carbon atom joins four other carbon atoms in regular tetrahedrons. The common structure of ice is a tetrahedral arrangement.

QUESTION: Hardness of transition metals is due to ______?
A. More melting point
B. More electrons
C. Variable oxidation state
D. Higher binding energies
EXPLANATION
Transition metals are able to form very strong metallic bonds and high bonding energies which results in hardness. The atoms of transition metals pack together more tightly with stronger bonds.

QUESTION: Which of the following solids is isotropic?
A. Ionic solids
B. Molecular solids
C. Amorphous solids
D. Metallic solids
EXPLANATION
Amorphous solids are isotropic, meaning their physical properties are identical in all directions. An amorphous solid is a solid in which there is no long-range order of the positions of the atoms.

QUESTION: The mechanism of reaction can be understood by
A. Experimental details
B. Balanced chemical equation
C. Molar Ratio
D. All of these
EXPLANATION
A reaction mechanism is a complete, detailed description of the reaction at the molecular level which specifies the individual collisions and reactions that result in the overall reaction.

QUESTION: Which of the following compound is formed when NACl reacts with CH3MgBr ?
A. CH3CN
B. CH3Cl
C. CH3CH2NH2
D. None of these
EXPLANATION
This is a double replacement reaction which occurs when two cations or anions switch places in a reaction to form two new compounds. In this reaction Cl changes place with MgBr resulting in CH3Cl being a new compound formed.

QUESTION: Which one of the following shows that iodoform test for a compound is positive?
A. Formation of carboxylate salt.
B. Brick red precipitate formation.
C. Yellow crystals.
D. Formation of water.
EXPLANATION
The iodoform test is a test to determine if an organic compound is ethanol or contains secondary alcohol (CH3—CH(OH)R). Potassium iodide and sodium hypochlorite solution are added to the organic compound in the presence of sodium hydroxide solution. Yellow crystals of the iodoform separate if the test is positive.

QUESTION: LDH-1 is raised in which disease:
A. Rickets
B. Anemia
C. Heart disorders other than stroke
D. Stroke
EXPLANATION
Conditions that can cause increased LDH-1 (Lactate dehydrogenase) in the blood include liver disease, heart attack, anemia, muscle trauma, bone fractures, cancers, and infections such as meningitis, encephalitis, and HIV.

QUESTION: Hydroxide Ions are combined to give _______.
A. Alcohols
B. Aldehydes
C. Oxygen
D. Hydrogen
EXPLANATION
Hydroxide ions (OH-) are attracted to the anode, they lose electrons and form oxygen gas. H+ ions are attracted to the cathode, they gain electrons and form hydrogen gas.

QUESTION: The transition elements belongs to Group VI B are
A. Zn, Cd, Hg
B. Fe, Ru, Os
C. Mn, Te, Re
D. Cr, Mo, W
EXPLANATION
Looking at the periodic table, group VI (6) contains the elements Cr, Mo, and W. Transition metals range from group 4 to group 12 in the periodic table.

QUESTION: Benzene molecule contains:
A. Three triple bonds
B. Two double bonds
C. Three double bonds
D. No multiband
EXPLANATION
Benzene is aromatic meaning it is a six-membered structured-like ring that contains three double bonds.

QUESTION: When an electron jumps from n = 5 to n = 2 having wave number equal to 2.3 x 16 m-1. In which spectral series will it fall?
A. Layman
B. Balmer
C. Visible
D. Infrared
EXPLANATION
Explanation for this question will be added shortly.

QUESTION: The electrical conductivity of metal sometimes decreases with the ?
A. Increase in pressure
B. Increase in temperature
C. Decrease in temperature
D. Decrease in pressure
EXPLANATION
As the temperature increases, the vibrational motion of electrons increases and causes extra collisions which results in the increase of resistance in metals. The movement of electrons decreases and causes decrease in conductivity.

QUESTION: Which unit of pressure is commonly used by meteorologist?
A. Atm
B. Pascal
C. mm of Hg
D. Millibar
EXPLANATION
Millibar is the unit of air pressure in the metric system used in meteorology.

QUESTION: Liquid hydrocarbons are converted into gaseous hydrocarbon by?
A. Cracking
B. Hydrolysis
C. Oxidation
D. Distillation
EXPLANATION
Cracking is the process of converting large hydrocarbon molecules into smaller ones through the application of a catalyst.

QUESTION: The total number of bond angles in methane are ____.
A. 2
B. 3
C. 5
D. 4
EXPLANATION
Methane is tetrahedral with 4 equal bond angles equal to 109.5°

QUESTION: A molecule of water has two bond, so 1 mole of water will contain ____ moles of bonds.
A. 1
B. 2
C. 3
D. 4
EXPLANATION
Fact.

QUESTION: During preparation of Acetaldehyde from ethanol in laboratory, why acetaldehyde is distilled off quickly after formation?
A. To avoid decomposition of product.
B. To avoid reduction.
C. To avoid further oxidation to acetic acid.
D. None of these.
EXPLANATION
Fact.

QUESTION: Which of the following bond has highest bond energy value?
A. C-I
B. C-H
C. C-CI
D. C-F
EXPLANATION
Fluorine is the most electronegative element, so it creates the highest bond energy with another element.

QUESTION: In a vacuum distillation the boiling point of glycerin is reduced to _____?
A. 290°C
B. 110°C
C. 156°C
D. 210°C
EXPLANATION
Vacuum distillation is a method carried out under reduced pressure of distillation. The vacuum lowers ambient pressure, which lowers the temperature that the liquid must reach in order to have sufficient vapor pressure to boil. Glycerin is reduced to 210˚C.

QUESTION: Magnetic induction is also called _____.
A. Flux
B. Magnetization
C. Magnetic intensity
D. Flux intensity
EXPLANATION
Fact.

QUESTION: Consider a capacitor has vacuum in the space between the conductors. If we double the amount of charge on each conductor, what happens to the capacitance?
A. It increases
B. It decreases
C. It remains same
D. It depends on the size or shape of the conductors.
EXPLANATION
Explanation for this question will be added shortly.

QUESTION: The speed of sound in a metal is approximately:
A. 1500 m/s
B. 5000 m/s
C. 330 m/s
D. 50 m/s
EXPLANATION
The speed of sound in solids is approximately 5000ms-1. Since metals are generally solids, we can assume that the speed of sound in metals is approximately 5000ms-1. The speed of sound in air is 330ms-1 and the speed of sound in water is approximately 1500ms-1.

QUESTION: The acceleration is a _____.
A. Vector quantity
B. Scalar quantity
C. Dimensionless quantity
D. None of these
EXPLANATION
This is a standard answer. Acceleration is a vector quantity. It is a vector quantity because it has both magnitude and direction.

QUESTION: _____ are such nuclei of an element that have the same atomic number Z, but have different mass number.
A. Isotopes
B. Isobars
C. Isomers
D. Isotherms
EXPLANATION
Isotopes have the same number of protons (Atomic Number) and electrons but they have different numbers of neutrons. This means that their mass number is different. The difference in the number of neutrons between the various isotopes of an element means that the various isotopes of the same element have different masses. Carbon 12 and Carbon 14 are both isotopes of carbon, one with 6 neutrons and one with 8 neutrons (both with 6 protons). Carbon-12 is a stable isotope, while carbon-14 is a radioactive isotope (radioisotope).

QUESTION: Which of the following is equivalent to a temperature 350K?
A. 77°C
B. -77°C
C. 623 °C
D. -623 °C
EXPLANATION
Temperature in Kelvin = Temperature Celsius + 273.15 Temperature Celsius = Temperature in Kelvin - 273.15 = 77°C

QUESTION: A body is travelling in a circle of radius r at a speed v. Its centripetal acceleration will be ___.
A. a = r2 / v
B. a = r / v
C. a = v2 / r
D. a = v / r
EXPLANATION
The formulae for acceleration in uniform circular motion are:             a=vω a=rω2 a=v2/r             Where is the centripetal acceleration             V is the linear velocity             Ω is the angular velocity             R is the radius of the circular path

QUESTION: Principle of transformer is ?
A. Mutual inductance
B. Self-induction
C. Motional emf
D. None of these
EXPLANATION
A transformer is a device used in the power transmission of electric energy. The transmission current is AC. It is commonly used to increase or decrease the supply voltage without a change in the frequency of AC between circuits. The transformer works on the principle of Faraday’s Law of electromagnetic induction and mutual induction. A transformer carries the operations shown below: Transfer of electric power from one circuit to another. Transfer of electric power without any change in frequency. Transfer with the principle of electromagnetic induction.

QUESTION: Two objects, with different sizes, masses, and temperatures, are placed in thermal contact. In which direction does the energy travel?
A. Energy travels from the larger object to the smaller object.
B. Energy travels from the object with more mass to the one with less mass.
C. Energy travels from the object at higher temperature to the object at lower temperature.
D. Energy does not travel.
EXPLANATION
Heat/Thermal Energy will always be transferred from the hotter object to the cooler object. Whenever heat energy is transferred to an object, its temperature will rise. You can imagine this from a simple example. A cup of tea placed will become colder as it loses thermal energy to the surroundings. It will not get hotter. If the two objects are in thermal contact and do not exchange heat, then they are in thermal equilibrium.

QUESTION: A diode works in _______ bias for rectification.
A. Forward
B. Reverse
C. Mid
D. Positive
EXPLANATION
Diodes, in rectification, only allow current to pass through in one direction. They can either be reversed or forward though subjectively, reversed diode is a forward diode, without any standard of comparison hence Option A.

QUESTION: Ohms law is applicable to _____.
A. Semiconductor
B. Vacuum tubes
C. Carbon resistors
D. None of these
EXPLANATION
All AC and DC circuits and conductors obey Ohm’s Law. Ohms law is not applicable to electron tubes, discharge tubes, semiconductors and electrolytes. This is because their I-V graph is a curved line instead of a straight line.

QUESTION: Platinum wire becomes yellow at a temperature of ________ degree C.
A. 900
B. 500
C. 1300
D. 1600
EXPLANATION
This is a standard answer. Platinum wire becomes yellow at the temperature of 1300°C.

QUESTION: Under the action of the restoring force:
A. The speed of the body always increases.
B. The body moves at constant speed.
C. The body always slows down.
D. The body accelerates.
EXPLANATION
The restoring force is a function only of the position of the mass or particle, and it is always directed back toward the equilibrium position of the system. The restoring force causes the vibrating object to slow down as it moves away from the equilibrium position and to speed up as it approaches the equilibrium position. Note that the restoring force does not cause the body to move at a constant speed if that is the case the body would never reach an equilibrium position. Restoring forces bring the body to its equilibrium position, the object has an acceleration directed towards the mean position. We say there is acceleration because the body is not in its equilibrium position. It is neither at rest nor moving with constant speed and this means there is a resultant force on the body. Whenever there is a resultant force, according to Newton’s 2nd law, there will be an acceleration.

QUESTION: What is the relationship between Power, Current and voltage?
A. P=V/I
B. P=VI
C. 2P=I+V
D. All of them
EXPLANATION
This is a standard answer. The relationship between power, current and voltage is P=VI.

QUESTION: Calculate the work done when a 2 N force moves a body through a distance of 10 m.
A. 10 J
B. 2 J
C. 5 J
D. 20 J
EXPLANATION
Given, Force applied, F = 2 N Distance travelled, s = 10 m We know, Work done = Force applied x Distance moved W = F x s W = 2 x 10 W = 20 J

QUESTION: When an object moves on a circular path and come back to its initial position, then:
A. Only its distance is zero.
B. Only its displacement is zero.
C. Neither distance nor displacement is zero.
D. Both distance and displacement is zero.
EXPLANATION
When an object moves in a circular path and returns back to its initial position then only its displacement is zero. This is because displacement is a vector quantity. It is the distance moved from a certain reference point or the shortest distance between 2 points. When the object completes one revolution and comes to point A the distance traveled will be equal to the circumference of the circular path whereas if we draw a straight line between the start point and end point the length is zero and hence displacement is zero.

QUESTION: Average velocity is defined as _______.
A. Displacement/time
B. Distance/time
C. Distance x time
D. Displacement x time
EXPLANATION
This is a standard answer. Velocity = Displacement/time. Speed is Distance/time.

QUESTION: Plancks constant is analogous to:
A. Inertia
B. Wave nature
C. Angular momentum
D. Linear momentum
EXPLANATION
The Planck’s Constant has the same dimensions as the moment of inertia Energy of a photon, E=hf Where h is the planck’s constant and f is the frequency. Therefore, [h] = [E]/[f] =[ML2T-2]/[T-2] Angular momentum = Moment of Inertia x Angular velocity                                 = [ML2][T-1]

QUESTION: If a horse pulls a cart, work done by horse is ?
A. Negative
B. Zero
C. Positive
D. None of these
EXPLANATION
When the horse pulls the cart, the cart moves in the direction of the force applied

QUESTION: 87Ra221 is a radioactive substance having half-life of 4 days. Find the probability that a nucleus undergoes decay after two half-lives.
A. 1
B. 1/2
C. 3/4
D. 1/4
EXPLANATION
Correct option is C.

QUESTION: Coulombs law is true for
A. Atomic distance
B. Nuclear distance
C. Charge as well as uncharged particle
D. All of the distances
EXPLANATION
Coulombs law is true for all distances whether it is small or large. Hence it is called a long-range force. It is valid for any distance. However, Coulomb’s Law is not valid for uncharged particles.

QUESTION: Question is given below.
A. Series
B. Parallel
C. Both of them
D. None of them
EXPLANATION
This is the formula for Capacitance in Series. The C in the equation indicates Capacitance.

QUESTION: Which of the given motion is a type of 2D motion?
A. Circular
B. Pendulum motion
C. Projectile motion
D. All of these
EXPLANATION
All these are examples of 2D motion as motion that takes place in two different directions (or coordinates) at the same time, i.e. in y-direction and in x-direction.

QUESTION: Which of the following has a negative temperature coefficient of resistance?
A. Tungsten
B. Carbon
C. Nichrome
D. Platinum
EXPLANATION
A negative temperature coefficient (NTC) refers to materials that experience a decrease in electrical resistance when their temperature is raised. Semiconductor materials (carbon, silicon, germanium) typically have negative temperature coefficients of resistance.

QUESTION: The radiation reached on earth by sun is
A. Alpha
B. Beta
C. Gamma
D. All of these
EXPLANATION
All of the energy from the Sun that reaches the Earth arrives as solar radiation. Solar radiation includes visible light, ultraviolet light, infrared, radio waves, X-rays, and gamma rays.

QUESTION: The temperature coefficient of resistance is expressed in:
A. °C
B. °C-1
C. m0C-1
D. None of these
EXPLANATION
This is a standard answer. The temperature coefficient of resistance is generally defined as the change in electrical resistance of a substance with respect to per degree change in temperature. It is expressed in °C-1.

QUESTION: A nucleus emits an α- particle, followed by two β- particles. The final nucleus will be:
A. An isotone of the original one
B. An isotope of the onginal one
C. An isobar of the original one
D. None of these
EXPLANATION
In alpha decay, the mass number decreases by 4 and the Atomic Number decreases by 2. In each beta decay, the Atomic number increases by 1 but the mass number remains unchanged. ​ mnX ⟶ α + m-4n-2Y ⟶ 2β + m-4nX The final nucleus is therefore the isotope of the original one as there is no change in the number of electrons and protons but there is only a change in the number of neutrons.

QUESTION: Which of the following is an assumption of the kinetic model of an ideal gas?
A. Gas is at high pressure
B. Collision between particles are elastic
C. There are weak forces of attraction between particles in gas
D. Total energy of particles is proportional to the temperature
EXPLANATION
The kinetic-molecular theory of gasses assumes that ideal gas molecules (1) are constantly moving; (2) have negligible volume; (3) have negligible intermolecular forces; (4) undergo perfectly elastic collisions; and (5) have an average kinetic energy proportional to the ideal gas’s absolute temperature. The average kinetic energy of the gas molecules is directly proportional to the absolute temperature. Notice that the term “average” is very important here; the velocities and kinetic energies of individual molecules will span a wide range of values, and some will even have zero velocity at a given instant.

QUESTION: Calculate the frequency if the number of revolutions is 300 and the paired poles are 50.
A. 15 kHz
B. 150 kHz
C. 1500 kHz
D. 150 Hz
EXPLANATION
We know that f=p x n f=50x300=15000 Hz = 15kHz.

QUESTION: If a transverse wave travelling in a rarer medium is incident on a denser medium, it is reflected such that...
A. It undergoes a phase change of 90 deg
B. It undergoes a phase change of 180 deg
C. It undergoes a phase change of 270 deg
D. It undergoes a phase change of 0 deg
EXPLANATION
Whenever a wave undergoes reflection at a denser medium then its crest is reflected at trough and vice versa, so its phase change is 180°.

QUESTION: One radian means
A. Arc length of unit radius is half
B. Arc length of unit radius is unity
C. One degree
D. All of these
EXPLANATION
This is a standard answer. One radian is the angle subtended at the center of a circle by an arc length equal to the radius of the circle.

QUESTION: A man moves a roller through a distance of 20 m. 10 N of applied force is inclined at 60° of direction of motion what will be the work done by the man?
A. 100 J
B. 50 J
EXPLANATION
Given that Force applied = 10N       The distance covered = 20m       The angle between force and displacement = 60° Work done= Fdcosθ                  = 10x20cos60                  = 100J

QUESTION: Four wires of same material, the same cross-sectional area and the same length when connected in parallel give a resistance of 0.25 ohms. If the same four wires are connected is series the effective resistance will be?
A. 1 ohm
B. 2 ohm
C. 3 ohm
D. 4 ohm
EXPLANATION
For wires in Parallel 1/Rtotal = 1/R + 1/R + 1/R + 1/R 1/0.25 = 4/R  4 = 4/R  R = 4/4 R = 1Ω So, the resistance of each resistor is 1Ω For 4 resistors in Series Rtotal = R+R+R+R         = 1+1+1+1         = 4Ω

QUESTION: A stationary wave is set up in a pipe of length L, which is is open from one end. There are three nodes. How many antinodes are there in the stationary wave?
A. 2
B. 3
C. 4
D. 6
EXPLANATION
Refer to the diagram. A = Antinode, N = Node

QUESTION: Which of the following is not an assumption of the kinetic model of an ideal gas?
A. Particles collide elastically
B. Kinetic energy of a given particle is same
C. The duration of collision between molecules is very short
D. Intermolecular potential energy of the molecules is zero
EXPLANATION
The kinetic theory describes a gas as a large number of submicroscopic particles, all of which are in constant, random motion. It states that: 1. All collisions between gas molecules are perfectly elastic and short in duration. Thus all kinetic energy is conserved (Hence A and C are correct) 2. Intermolecular forces between gas molecules is negligible thus intermolecular potential energy of the molecules is zero (Hence D is correct) Thus Option B is the answer as it does not comply with the kinetic model of an ideal gas.

QUESTION: A body of mass m kg is lifted by a man to a height of one metre in 30 sec.Another man lifts the same mass to the same height in 60 sec. The work done by them are in the ratio:
A. 1 : 1
B. 2 : 1
C. 4 : 1
D. 1 : 2
EXPLANATION
Correct option is 1 : 1.

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
According to Coulomb’s Law F1 = k/d2  k=F1d2  F2 = k/(d/2)2  = 4F1d2/d2  = 4F1

QUESTION: A radioactive source has a half-life of 80s. How long will it take for 7/8 of the source to decay?
A. 10s
B. 70s
C. 240s
D. 640s
EXPLANATION
Given that the half life is 80s         Then λ = 0.693/t1/2                     = 0.693/80 If ⅞th of the source has decade this means that only 1/8th is left. Using the formula: N=N0 e-λt N/N0 = e-(0.693/80)t  1/8 = e-(0.693/80)t  ln(⅛) = -(0.693/80)t  Then t = ln(⅛) / -(0.693/80) Therefore t = 240s

QUESTION: In full wave rectifier with input frequency 50 Hz the ripple in the output is mainly of frequency
A. 25 Hz
B. 50Hz
C. 100 Hz
D. Zero
EXPLANATION
In full-wave rectification, ripple frequency is twice the input frequency whereas for half-wave rectifiers it is equal to the AC supply frequency.

QUESTION: In order to enhance magnetic flux, the primary and secondary coils of the transformer are wound on
EXPLANATION
This is a standard answer. The core of a transformer is made of soft iron because it has high permeability so it provides complete linkage of magnetic flux of the primary coil to the secondary coil. Therefore it has high coercivity and low retentivity.

QUESTION: Magnetic field will not produce in case of?
A. Charged positive particles
B. Charged negative particles
C. Neutral particles
D. All of these
EXPLANATION
This is a standard answer. The magnetic field will not be produced in case of neutral particles.

QUESTION: An ideal reversible heat engine is 1 efficient only if:
A. Hot reservoir is at 0K
B. Hot reservoir is at 0C
C. Cold reservoir is at 0C
D. Cold reservoir is at 0K
EXPLANATION
This is a standard answer. The cold reservoir should be at 0K, also known as absolute 0.

QUESTION: Diffraction is prominent when the wavelength of light is:
A. Five time small as compared with the size of the obstacle
B. Large as compared with the mass of the obstacle
C. Large as compared with the size of the obstacle
D. One half as compared with the size of the obstacle
EXPLANATION
Diffraction is basically the bending of waves. The bending occurs due to obstacles. It occurs only when the wavelength is comparable to the size of the aperture. As the wavelength increases, the diffraction effect will also increase. Thus for greater diffraction, it is important that the size of the obstacle is directly proportional to the wavelength of the source. Hence for diffraction, size of othe bstacle should be in the order of a wavelength.

QUESTION: A 18.0 V battery is connected to a capacitor, resulting in 27.0 μC of charge stored on the capacitor. How much energy is stored in the capacitor?
A. 2.43 X 10-4 J
B. 4.86 X 10-4 J
C. 2.43 X 10-2 J
D. 4.86 X 10-2 J
EXPLANATION
Energy stored by the Capacitor = ½ QV = ½ x 18 x 27x10-6 = 2.43x10-4J

QUESTION: Which light photon has the least momentum?
A. Red
B. Green
C. Yellow
D. Blue
EXPLANATION
λ = h / p Where p is the linear momentum The visible region of the electromagnetic spectrum consists of lights of colour: Red Orange Yellow Green Blue Indigo Violet Red has the largest wavelength and shortest frequency and Violet has the shortest wavelength and highest frequency. Therefore, p = h / λ  We can see from here that since Red photon has the largest wavelength it will have the least momentum as p∝1/λ

QUESTION: A stone is thrown from a bridge at an angle of 30o with the horizontal in the downward direction with a speed of 25m/s. If the stone strikes the water after 2.5 sec, then calculate the height of the bridge from the water surface (g=9.8m/s2)
A. 61.9 m
B. 35 m
C. 70 m
D. None
EXPLANATION
Correct option is A.

QUESTION: Acceleration due to gravity near earth is
A. Nonuniform
B. Uniform
C. Decreasing with distance
D. Increasing with time
EXPLANATION
This is a standard answer. The acceleration due to gravity near the earth’s surface is uniform. The value of g varies insignificantly if the distance between the body and the surface of the earth is very small as compared to the average radius of the earth. Therefore, for practical purposes, we take acceleration due to gravity as a constant.

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
The formula for resistance of wire is: R = ρl/A = ρl/πr2 Where ρ is the specific resistance or resistivity. Specific resistance will remain the same as it is a material’s property and only depends only on temperature   Rnew = ρ2l/π(2r2) Rnew = ρl/2πr2 Since R = ρl/πr2 Rnew = R/2

QUESTION: The two points of a medium are separated through a distance of 10 cm. What is the phase angle between these two points if the wavelength of the wave is 0.1 m?
A. π
B. 2π
C. 3π
D. 3π/4
EXPLANATION
The distance between the two points in the wavelength of the wave as 0.1m is equal to 10cm. Thus, it is obvious that the phase angle would be 2π.

QUESTION: If a charged particle kept at rest experiences an electromagnetic force
A. the electric field must not be zero
B. the magnetic field must not be zero
C. the electric field may or may not be zero
D. the magnetic field may or may not be zero
E. Option A and D are correct.
EXPLANATION
Electromagnetic force is the force on charged particle due to both electric field and magnetic field. Also, the electric force can be experienced by charges at rest. Magnetic force can be experienced by charges in motion. Hence, if a charged particle kept at rest experiences an electromagnetic force, the electric field must not be zero and the magnetic field may or may not be zero.

QUESTION: If the wavelength of a wave is 20 cm and its time period is T, what is the distance travelled by a crest on the wave in 1.25T?
A. 30 cm
B. 25 cm
C. 15 cm
D. 40 cm
EXPLANATION
Given that λ = 20cm We know that v=fλ  v=λ /T v= 20/T s=vt s=(20/T)x1.25T s=20 x 1.25 s=25 cm

QUESTION: When gamma photon is entered in nucleus it _______
A. De-excites the atom
B. Excites the atom
C. Scatters by atom
D. None of these
EXPLANATION
When a gamma photon enters the nucleus it will excite the atom. When a gamma photon is emitted from a nucleus it will de-excite the atom.

QUESTION: A resistance of 40 Ohms is attached to a circuit having current of 300 Amp, Find its voltage.
A. 12000 volts
B. 15000 volts
C. 20000 volts
D. 300 volts
EXPLANATION
V=IR =300x40 =12000 V

QUESTION: The number of neutrons emerged out in a single nucleus during fission reaction are
A. Infinite
B. Zero
C. 3
D. None of these
EXPLANATION
This is a standard answer. In a nuclear reactor, a neutron is absorbed into a nucleus (typically uranium-235). This causes the nucleus to become uranium-236, which is violently unstable.

QUESTION: During an adiabatic process the pressure of the gas is found to be proportional to fourth power of temperature. The ideal gas would be
A. H2
B. He
C. CH2
D. Mixture of H2 and He
EXPLANATION
α,β,γ below are constants. Ideal gas equation: PV=nRT, Given that: P=αT4 T4 = P/α and since, as we established from Ideal gas law, the temperature is proportional to the product of pressure and time, we can write: T = βPV T4 = (βPV)4 Therefore: (βPV)4 = P/α P3V4 = c Where c is a constant Raise both sides of the equation to the power of 1/3: PV4/3 = c1/3 Consider c1/3 as a new constant k Therefore: PV4/3 = k An adiabatic process is described by PVɤ = constant   Since the right part of the previous equation is a constant, comparing it with the adiabatic equation, we see that   ɤ = 4/3    Express the adiabatic constant in terms of degree of freedom f: ɤ = 1+ 2/f 4/3 = 1 + 2/f F = 6 degrees of freedom, which corresponds to The answer is CH2

QUESTION: A container is filled with oxygen and helium at the same temperature. The molar mass of oxygen is 32 g/mol and that of helium is 4g/mol. What is the ratio: average speed of oxygen molecules/ average speed of helium molecules?
A. 1 /√8
B. √8
C. 1/ 8
D. 8
EXPLANATION
The average speed of a molecule is directly proportional to the square root of the temperature at which the gas is kept and indirectly proportional to molar mass The formula for average speed is  <c> = √ 8RT/πm where R is gas constant, T is the temperature of the gas and m is the molar mass of the gas. Since the temperature for both gasses is the same and 8R/π is a constant, therefore the average speed depends inversely on the molar mass of gas. Let the average speed of oxygen be v1 and the average speed of helium be v2. Molar mass of oxygen (m1) = 32 g/mol Molar mass of helium (m2) = 4 g/mol v1/v2 = √ m2/m1            = √ 4/32            = √1/8            =1/√8

QUESTION: Statements (I) The children are being aggressive today. (II) There is no specific limit for children to use mobile screens
A. Statement 1 is the cause and 2 is the effect
B. Both of the statements 1 and 2 are independent.
C. Statement 2 is the cause and 1 is the effect
D. Both statements 1 and 2 are effects of some common cause
EXPLANATION
The root cause of children getting aggressive is their mobile phones hence limiting the time that children use their phones can solve this problem. lenient parentage is not the problem plus strict parenting sometimes causes rebellious behavior.

QUESTION: Which one does not belong to the other?
A. Apple
B. Mango
C. Cucumber
D. Orange
EXPLANATION
All except cucumber are fruits. Cucumber is a vegetable hence it does not belong to the others.

QUESTION: Statement Should children be prevented completely from watching television? Arguments (I) No. We get vital informafion regarding education through television. (II) Yes. It hampers the study of children. (III) Yes. Young children are misguided by certain programmes featuring violence.
A. Only I, II and III are strong
B. Only I is strong
C. Only I and II are strong
D. Only I and III are strong
EXPLANATION
Clearly, television offers various educational programs which are of great practical value to the students. So, it serves as a means (but it is not the only means) to educate the masses. Thus, I hold strong while IV does not. Besides, the demerits of watching television, mentioned in II and III, may be done away with by allowing children to watch selected programs on television, according to a set schedule. So, neither II nor III holds strong.

QUESTION: What is the multiplicative inverse of 1/2?
A. -2
B. 2
C. -1/2
D. Both A and B
EXPLANATION
To find the reciprocal/inverse of a fraction , interchange the numerator and denominator. Hence, reciprocal of 1/2 is 2

QUESTION: Find the different one
A. Mother
B. Sister
C. Maid
D. Aunt
EXPLANATION
Mother, sister, and aunt are all related to a person by blood hence they fall in the same category. However, a person has no blood relation with the maid, a female domestic servant, thus she is the odd one out/different one.

QUESTION: A competition always has
A. Reward
B. Rivals
C. Spectators
D. Referee
EXPLANATION
Competition may or may not have a Reward, Spectators, or referee. But competition always has Rivals i.e the opponents who compete with each other.

QUESTION: CMM, EOO, GQQ, _____, KUU
A. GRR
B. GSS
C. ISS
D. ITT
EXPLANATION
The first letters are in alphabetical order with a letter skipped in between each segment: C, E, G, I, K. The second and third letters are repeated; they are also in order with a skipped letter; M, O, Q, S, U.

QUESTION: What should come next to it infirmary
A. Surgery
B. Disease
C. Patient
D. Receptionist
EXPLANATION
An infirmary is a place that takes care of the infirm, sick or injured. Without patients, there is no infirmary. Surgery (choice a) may not be required for patients. A disease (choice b) is not necessary because the infirmary may only see patients with injuries. A receptionist (choice d) would be helpful but not essential.

QUESTION: Which one of the following has four sides
A. Triangle
B. Square
C. Circle
D. Right triangle
EXPLANATION
a triangle has 3 sides as “tri” is in the name which means 3. right-angled triangle also has 3 sides. A circle has no sides as A side requires two distinct endpoints joined by a straight line. For a circle, this will never be the case. A square has 4 corners hence it has 4 sides.

QUESTION: Chef: Restaurant
A. Doctor: Nurse
B. Driver: Passenger
C. Teacher: Schools
D. Writer: Editor
EXPLANATION
The chef works in a restaurant, and the teacher works in a school. Doctors and nurses are both workers and the pattern is an employee and their workplace.