PMC Paid Practice Tests Series 2021 With Explanation - Test 25

[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: Demonstrate the correct use of articles and prepositions: _______ ink in my pen is red.
A. A
B. An
C. The
D. No article is required
EXPLANATION
The sentence is referring to a specific ink, hence “the” will be used.

QUESTION: Choose the correct sentence:
A. Belgium and france fought over who would host the olympic games?
B. Belgium and France fought over who would host the Olympic Games.
C. Belgium and France: fought over who would host the Olympic Games!
D. Belgium and France fought over who would host the olympic games
EXPLANATION
Option B displays the correct use of capitalization to refer to proper nouns and the correct use of periods to indicate declaratory sentences.

QUESTION: Comprehend key vocabulary: Aslam and his friends were making too much noise. Their father got really ______ at them.
A. Afraid
B. Angry
C. Kind
D. Strong
EXPLANATION
This question tests vocabulary and interpretation of context. Correct option in terms of context of the given sentence is option B.

QUESTION: Demonstrate correct use of subject-verb agreement They _______ a letter.
A. Wrote
B. Written
C. Write
D. Writes
EXPLANATION
Since the subject “they” is plural, the verb used to refer to it must also be plural i.e “wrote”.

QUESTION: Demonstrate control of tenses and sentence structure Maryam _____ (see) the smoke of the fire rising all around.
A. See
B. Saw
C. Will see
D. Seen
EXPLANATION
Past tenses of verbs come after nouns, in this case, the proper noun “Maryam”.

QUESTION: Demonstrate control of tenses and sentence structure I________a strange noise.
A. Hear
B. Am hearing
C. Have been hearing
D. Hears
EXPLANATION
The subject in the given sentence is the “strange noise”. When referring to sounds perceived by ears, “hear” is used.

QUESTION: Demonstrate correct use of articles and prepositions Here is ______ photograph you were searching for.
A. A
B. An
C. The
D. No article
EXPLANATION
The ‘photograph’ in the sentence is a specific noun and hence will be preceded by “the”.

QUESTION: Comprehend key vocabulary: binnial
A. Plant that blooms twice a year
B. Occuring twice a year
C. Composed or created by two people
D. Occuring once every two years
EXPLANATION
This question tests vocabulary. Meaning of “Biennial” is to occur once every two years.

QUESTION: Demonstrate correct use of articles and prepositions Do you have _______ calculator? I need it to solve this sum.
A. A
B. An
C. The
D. No article
EXPLANATION
In the context of the given sentence, “calculator” is not a specific noun, hence it will be preceded by “a”.

QUESTION: Demonstrate correct use of subject-verb agreement Ninety rupees ___ too much for this bag.
A. Is
B. Are
C. Be
D. Were
EXPLANATION
The subject in this question is the singular noun “bag”, hence “is” will be used.

QUESTION: Demonstrate correct use of writing conventions of spelling, capitalization and punctuation to clarify meaning: where is
A. Wheres
B. Wheres
C. Wheres
D. Wheres
EXPLANATION
In contractions, apostrophe replaces the missing letters, in context of the question, the correct option is option B, “where’s”.

QUESTION: Demonstrate correct use of articles and prepositions Demonstrate correct use of subject-verb agreement Demonstrate correct use of writing conventions of spelling, capitalization and punctuation to clarify meaning If you lend him a book (A)/ he will lend it (B), to someone else (C) and never you will get it back. (D)
A. If you lend him a book
B. He will lend it
C. To someone else
D. And never you will get it back
EXPLANATION
Adverbs are placed after auxiliary verbs which include “will”. Hence, the correct option is option D.

QUESTION: Demonstrate correct use of articles and prepositions Demonstrate correct use of subject-verb agreement Demonstrate correct use of writing conventions of spelling, capitalization and punctuation to clarify meaning Even if the doctor (A)/ put in his best efforts, he (B)/ could not succeed in (C)/ saving the patient. (D)
A. Even if the doctor
B. Put in his best efforts, he
C. Could not succeed in
D. Saving the patient.
EXPLANATION
Statement B and C indicate past tense whereas statement A indicates future tense due to “Even if”. Hence, correct option is option A.

QUESTION: Demonstrate correct use of writing conventions of spelling, capitalization and punctuation to clarify meaning: he is
A. Hes
B. Hes
C. Hes
D. Heis
EXPLANATION
In contractions, apostrophe replaces the missing letters, in context of the question, the correct option is option B, “he’s”.

QUESTION: Demonstrate correct use of subject-verb agreement Physics _____ difficult to understand.
A. Were
B. Are
C. Is
D. Have been
EXPLANATION
The subject of the sentence is the singular proper noun Physics (The field of physics). Hence the singular verb “is” will be used to refer to it.

QUESTION: Demonstrate control of tenses and sentence structure Fetch me a glass of water.
A. Declarative
B. Imperative
C. Interrogative
D. Exclamatory
EXPLANATION
A request or instruction is being made, hence the sentence is imperative.

QUESTION: Demonstrate control of tenses and sentence structure What tense is the verb in this sentence? I got home from work at 6.30pm.
A. Present
B. past
C. Future
D. None of these
EXPLANATION
The given sentence is in past tense due to the presence of the past participle of get, which is got.

QUESTION: Demonstrate correct use of articles and prepositions Demonstrate correct use of subject-verb agreement Demonstrate correct use of writing conventions of spelling, capitalization and punctuation to clarify meaning I advised her ________ drink it.
A. Dont
B. Not to
C. To not
D. To dont
EXPLANATION
A preposition must be placed before the adverb. Hence, the correct option is option B.

QUESTION: Demonstrate control of tenses and sentence structure By next Saturday, I _______ (work) on this painting for exactly one month.
A. Will have been working
B. Will be working
C. Will work
D. Worked
EXPLANATION
Correct option is A because “By next Saturday” indicates future tense and option A displays perfect future tense structure.

QUESTION: Demonstrate correct use of subject-verb agreement The peon will not ___ the bell yet.
A. Has rings
B. Had rung
C. Have rung
D. Rings
EXPLANATION
Option C displays perfect past tense as the auxiliary verb “have” appears before the main verb “rung”.

QUESTION: What is a Provirus?
A. Free virus
B. Free DNA
C. Primitive virus
D. Intergrated viral genome
EXPLANATION
Option D is correct as a provirus is the genetic material of a virus as incorporated into, and able to replicate with, the genome of a host cell.

QUESTION: In parthenocarpy which levels are high in ovaries?
A. Gibberellins
B. Cytokinins
C. Auxins
D. All of these
EXPLANATION
Option C is correct as parthenocarpy is the natural or artificial inducing of fruit development in plants, and auxins are essential as they are plant hormones responsible for growth and development.

QUESTION: Thylakoids in chloroplasts are stacked into?
A. Grana
B. Stroma
C. Nucleus
D. None of these
EXPLANATION
Option A is correct as one grana is a bunch of thylakoids stacked together.

QUESTION: For a single gene trait, a number of genetic disorders are caused when an individual inherits?
A. Two dominant alleles
B. One dominant allele
C. One recessive allele
D. Two recessive alleles
EXPLANATION
Option D is correct as genetic disorder that is recessive the person needs two recessive alleles otherwise the gene wont express itself in the phenotype.

QUESTION: Which of the following bacteria are thick rigid and spiral?
A. Coccus
B. Vibrio
C. Spirillum
D. Bacillus
EXPLANATION
Option C is correct as bacteria classified as spirillum are spiral in shape.

QUESTION: The membrane of vacuole is called:
A. Tonoplast
B. Plasma membrane
C. Epidermis
D. Both B and C are correct
EXPLANATION
Option A is correct as the membrane of a vacuole is called a tonoplast.

QUESTION: A neuron located in the central nervous system that projects its axon outside the CNS is called:
A. Motor nerve
B. Sensory nerve
C. Both A and B
D. Mixed nerve
EXPLANATION
Option A is correct as a neurone directed away from the CNS is sending a signal towards a muscle for action/reaction thus it must be a motor neurone.

QUESTION: Lymphatic system consists of all the following except:
A. Lymph nodes
B. Blood
C. Lymphatic vessels
D. Lymph
EXPLANATION
Option B is correct as the lymphatic system transport bodily fluids that have drained from the blood into tissues and empties the lymph back into the blood.

QUESTION: Which one is the basic element found in all organic compounds?
A. Oxygen
B. Carbon
C. Hydrogen
D. All of these
EXPLANATION
Option D is correct as organic compounds consist of one or more atoms of carbon are covalently bonded to hydrogen, oxygen and nitrogen.

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
Option C is correct as a monosynaptic reflex arc is a direct connection between sense and action so contains only two neurons: sensory and motor.

QUESTION: Which of the following proteins directly interacts with the myosin-binding site on actin?
A. Tropomyosin
B. Troponin
C. Both a and b
D. None of these
EXPLANATION
Option A is correct because tropomyosin constantly covers the myosin binding sites on actin until troponin receives Calcium ions for muscle contraction.

QUESTION: The type of plastids found in roots of plants___________.
A. Chloroplasts
B. Chromoplasts
C. Leucoplasts
D. All of them
EXPLANATION
Option C is correct as leucoplasts are present in roots for the storage of nutrients and starch. No chloroplasts or chromoplasts as those are found in leaves and flowers.

QUESTION: Which of the following is not a described type of virus?
A. Virus containing double strand DNA
B. A virus containing single strand DNA
C. Virus containing single strand RNA
D. Virus containing single strand RNA and single strand DNA
EXPLANATION
Option D is correct as viruses can only either have DNA or RNA is them, not both.

QUESTION: In photosynthesis dark reaction,is called so because:
A. It occurs in dark
B. It does not require light energy
C. It cannot occur during daytime
D. It occurs more rapidly at night
EXPLANATION
Option B is correct as the light independent reaction in photosynthesis (Calvin cycle) is also called the dark reaction.

QUESTION: Outbreeding increases which of the following?
A. Homozygosity
B. Heterozygosity
C. Gene linkage
D. Gene pool
EXPLANATION
Option B is correct as outbreeding increases hybrid vigor and the reverse of inbreeding depression occurs. This increases heterozygosity which remasks potential deleterious recessive alleles.

QUESTION: Which one of the following surrounds the testicles?
A. Penis
B. Urethra
C. Sperm duct
D. Scrotum
EXPLANATION
Option D is correct as the outer layer that surrounds and supports the testicles is the scrotum.

QUESTION: Two pea plants are crossed. One plant is homozygous dominant for purple flowers, and the other is homozygous recessive for white flowers. What fraction of the F2 population will have white flowers?
A. 1/4
B. 1/2
C. 1/8
D. 1/16
EXPLANATION
Option A is correct AA × aa F1: Aa Aa F2: AA Aa Aa aa aa is the homozygous recessive flower that is white. It has a 1 in 4 chance of occurring in the F2 generation.

QUESTION: What is the length of duodenum in cm?
A. 15-20
B. 20-25
C. 21-25
D. 25-30
EXPLANATION
Option B is correct as average length of duodenum is between 20 to 25 cm.

QUESTION: Which of the following organisms have the greatest problem with photorespiration?
A. C4 plants
B. Heterotrophs
C. C3 plants
D. CAM plants
EXPLANATION
Option C is correct as only CAM and C4 plants have special systems to counteract photorespiration.

QUESTION: Homology means:
A. Similarity in characteristics resulting from common ancestors
B. Similarity in function from acquired characteristics
C. Study of similar organs but with different functions
D. Study of similar ograns but with different functions
EXPLANATION
Option A is correct as homology is the similarity of structure, function and physiology of different species with shared ancestors.

QUESTION: Tropical plants such as sugarcane show high efficiency of CO2 fixation because of:
A. Calvin cycle
B. Hatch-slack
C. TCA-cycle
D. All of these
EXPLANATION
Option B is correct as another name for carbon fixation is the hatch-slackpathway.

QUESTION: Biological molecules which catalyze a biochemical reaction and remain unchanged after completion of reaction are called?
A. Cofactor
B. Coenzymes
C. Activator
D. Enzymes
EXPLANATION
Option D is correct as enzymes catalyse reactions and dont take part in the response; therefore, they do not change.

QUESTION: Development of an egg into zygote without fertilization is called?
A. Parthenocarpy
B. Apomixis
C. Parthenogenesis
D. All of these
EXPLANATION
Option C is correct as parthenogenesis is the formation of zygote from ovum without fertilization, this is a normal process in some invertebrates and plants.

QUESTION: Mytilus and Anodonta are example of which type of Molluscs?
A. Gastropods
B. Bivalves
C. Cephalopods
D. None of the above
EXPLANATION
Option B is correct as both have an external covering that is a two-part hinged shell that contains a soft body which is characteristic to bivalves.

QUESTION: The Induced fit model was introduced by Kosh land in which of the following year?
A. 1960
B. 1961
C. 1959
D. 1966
EXPLANATION
Option C is correct because, in 1959, Koshland introduced the induced fit model.

QUESTION: What is the least common electron transport chain?
A. Non-cyclic electron flow
B. Cyclic electron flow
C. Circular electron flow
D. Both band c
EXPLANATION
Option B is correct as cyclic photophosphorylation only occurs when theres an excess of NADPH and no need to produce more.

QUESTION: Out of 31 pairs of spinal nerves, how many pairs of thoracic nerves are there?
A. 8
B. 10
C. 12
D. 15
EXPLANATION
Option C is correct as there are 12 spinal root pairs in the thorax.

QUESTION: Radula is a characteristic feature of:
A. Myriapods
B. Molluscs
C. Echinoderms
D. Cnidaria
EXPLANATION
Option B is correct as radula is a structure of tiny teeth used to scrape food particles off a surface and draw them into the mouth found in molluscs.

QUESTION: SIV is the abbreviation of:
A. Simian immunodeficiency virus
B. Silurian immunodeficiency virus
C. Siberian immunodeficiency virus
D. Both A and C are correct
EXPLANATION
Option A is correct as SIV is the version of HIV that affects monkeys/apes.

QUESTION: Where does the molecular mechanism of oxidative phosphorylation take place?
A. Cytosol
B. Mitochondria
C. Nucleus
D. All of these options are correct
EXPLANATION
Option B is correct as oxidative phosphorylation occurs in the inner mitochondrial membrane, where the electron transport chain and stalked particles are located.

QUESTION: Ribosomes are chemically composed of which of the following?
A. Protein
B. DNA
C. RNA
D. Both Option A and C are correct
EXPLANATION
Option D is correct as ribosomes are complex molecules made up of ribosomal RNA and proteins.

QUESTION: The spinal cord is divided into how many different regions?
A. 2
B. 4
C. 6
D. 8
EXPLANATION
Option B is correct as the spinal cord is divided in 4 parts: cervical, thoracic, lumbar and sacral.

QUESTION: If the genetic diversity is low, then the chance of extinction is?
A. Decreased
B. Increased
C. Remains the same
D. Becomes zero
EXPLANATION
Option B is correct as less genetic diversity is the raw material of evolution. Without genetic variation, a population cannot evolve in response to changing environmental variables and, as a result, may face an increased risk of extinction.

QUESTION: The process through which organisms get oxygen for their cells from their surrounding environment is known as:
A. Respiratory exchange
B. Gaseous exchange
C. Diffusion
D. Osmosis
EXPLANATION
Option A is correct as respiratory exchange means the removal of carbon dioxide from cells and supplying oxygen to cells via the blood. Option B is incorrect as gaseous exchange is the physical process in the alveoli where blood is oxygenated. Option C is incorrect as diffusion is just the passive process of moving particles from an area of high concentration to an area of low concentration.  Option D is incorrect as osmosis is the passive process of water moving from higher water potential to an area of lower water potential through a partially permeable membrane.

QUESTION: Viviparous animals are those in which?
A. Internal fertilization occurs with external development in eggs
B. Internal fertilization occurs along with internal development followed by hatching of egg
C. External fertilization occurs with external development
D. Internal fertilization occurs with internal development inside female body
EXPLANATION
Option D is correct as viviparous refers to producing live young without eggs. Oviparous is the birth of young from laid eggs. Ovoviviparous is the birth of young from eggs that hatch inside the parent.

QUESTION: Apomixis is a form of which of the following?
A. Parthenocarpy
B. Parthenogenesis
C. Vernalization
D. All of these options are correct
EXPLANATION
Option B is correct as apomixis is the asexual reproduction of plants. Parthenogenesis is the formation of a zygote without fertilization, therefore, needing only one parent and no need for sexual reproduction.

QUESTION: The enzyme which plays an important role in HIV pathogenesis:
A. RNA polymerase I
B. DNA polymerase II
C. Reverse Transcriptase I
D. Reverse Transcriptase
EXPLANATION
Option D is correct as HIV is a retrovirus and all retroviruses contain simple stranded RNA, which is used with the aid of reverse transcriptase to produce viral DNA to infect cells.

QUESTION: The largest part of the human brain is the?
A. Cerebrum
B. Thalamus
C. Hypothalamus
D. Limbic system
EXPLANATION
Option A is correct according to the image below, where the pink region is the cerebrum.

QUESTION: The smallest monosaccharide is?
A. Triose
B. Diose
C. Monose
D. None of these
EXPLANATION
Option A is correct as monosaccharides are the simplest forms of carbohydrates. The simplest monosaccharides are trioses made of only three carbons. We can have three possible trioses: L-Glyceraldehyde, D-Glyceraldehyde, and dihydroxyacetone.

QUESTION: The reaction will proceed faster if the activation energy is?
A. High
B. Low
C. Remains same
D. None of these
EXPLANATION
Option B is correct as less activation energy means less energy is supplied for reaction to take place, less time required so rate increases.

QUESTION: The pores through which water enters the sponge body are called:
A. Osculi
B. Ostia
C. Opercula
D. None of the above
EXPLANATION
Option A is incorrect as osculi are large apertures in the sponge body from which water is expelled.  Option B is correct as pores in the sponge body are called ostia.  Option C is incorrect as the operculum is the structure that covers the osculi.

QUESTION: Flagella might have arisen through the ingestion of which of the following?
A. Cyanobacteria
B. Chlamydomonas
C. Paramecium
D. Spirochetes
EXPLANATION
Option D is correct as most of the spirochetes are characterized by their distinct shapes and unique motility. They are long, thin bacteria that can be shaped like flat waves, helices or have more irregular morphologies. Thus bacteria could gain their traits from ingestion and allow flagella to arise.

QUESTION: Essential fatty acids show all the characters except ________.
A. Lipotropism
B. Blood cloting factors
C. Used for energy production
D. None of these
EXPLANATION
Option D is correct as essential fatty acids are used in energy production, help in the clotting of blood and essential fatty acids affect lipotropic movement.

QUESTION: What is not true about cartilage?
A. There are many blood vessels in the cartilage
B. It is a form of connective tissue
C. It covers ends of the bone at the joint
D. Both A and B
EXPLANATION
Option A is correct as cartilage is the main type of connective tissue found throughout the body in bones, joints, spine, lungs and nose. It has structural and functional purposes and dies not contain any blood vessels.

QUESTION: Which of the following condition is hybrid?
A. AA
B. Aa
C. aa
D. All of these
EXPLANATION
Option B is correct as Aa shows that the gene has two different alleles so it is heterozygous or hybrid.

QUESTION: Which of the following is false about the sarcoplasmic reticulum?
A. The sarcoplasmic reticulum is a specialized smooth endoplasmic reticulum
B. The sarcoplasmic reticulum releases calcium ions into the cytoplasm of the muscle cell
C. A change in membrane potential causes the sarcoplasmic reticulum to become more permeable to calcium ions
D. The sarcoplasmic reticulum is found only in voluntary muscle cells
EXPLANATION
Option D is correct as sarcoplasmic reticulum is found in all muscle cells as it is necessary for muscle contraction.

QUESTION: Which statement correctly describes why enzyme activity increases with increased enzyme concentration?
A. Collisions between enzyme and substrate molecules increase because of increased kinetic energy.
B. Collisions between enzyme and substrate molecules increase because of increased heat energy
C. Collisions between enzyme and substrate molecules increase because more active sites are available
D. Collisions between enzyme and substrate molecules increase because more substrate molecules are available
EXPLANATION
Option C is correct as increased enzyme concentration allows for a higher frequency of effective collisions between enzyme and substrate as well as more active sites available for substrates; thus, enzyme activity rate increases.

QUESTION: Which cell organelle is involved in apoptosis?
A. Lysosomes
B. ER
C. Golgi
D. Mitochondria
EXPLANATION
Option A is correct as apoptosis is the process by which a cell dies, and lysosomes are organelles with special enzymes that break down the cell nearing its death.

QUESTION: What is a vestigial trait?
A. A trait that makes an organism better suited to a habitat
B. A structure that has origins in a common ancestor, but has evolved to perform different functions
C. A change to a cells genome
D. A structure that has lost its function but has been retained
EXPLANATION
Option D is correct as a vestigial trait is a characteristic of a species that was lost by evolution due to lack of need for that trait.

QUESTION: Which product is formed when carbon dioxide combines with amino group of haemoglobin?
A. Carboxyhemoglobin
B. Plasma proteins
C. Bicarbonate ions
D. Histamines
EXPLANATION
Option A is correct as when blood is deoxygenated, haemoglobin binds to carbon dioxide to form carboxyhemoglobin.

QUESTION: Under the microscope, the bacteria appear a bluish-purple color. Which class of bacteria are on the slide?
A. Helix
B. Around
C. Rod
D. Rigid helix
EXPLANATION
Option C is correct as rod shaped bacteria are gram positive which stain bluish-purple.

QUESTION: This jelly like substance inside the plasma membrane in which all cell organelles are floating is?
A. Cytoplasm
B. Tonoplasm
C. Karyoplasm
D. Cell sap
EXPLANATION
Option A is correct as the fluid in which all organelles are suspended in a cell is called the cytoplasm. It is mainly composed of water, salts and proteins and is enclosed by the cell membrane.

QUESTION: Which of the following is an incorrect difference between a shark and a whale?
A. A sharks heart has only one chamber whereas a whales heart has two chambers
B. Shark gills are not covered by operculum whereas those in a whale are
C. Sharks do not possess a swim bladder whereas whales do
D. Sharks have placoid scales on their skin whereas whales dont
EXPLANATION
Option A is correct as sharks have two chambered hearts and whales have four chambered hearts. Option B is incorrect as shark gills do not have an operculum. Option C is incorrect as whales do not possess a swim bladder but rather a homologous organ like a swim bladder.  Option D is incorrect as both sharks and whales have placoid scales.

QUESTION: Which molecule passes the mitochondrial membrane to begin the krebs cycle?
A. ATP
B. ADP
C. NADH
D. Acetyl coA
EXPLANATION
Option D is correct as after glycolysis and links reaction in the mitochondria produce acetyl CoA it is then used in the Krebs cycle to produce energy by a series of chemical reactions.

QUESTION: Which term is used to refer to an inactive enzyme precursor?
A. Apoenzyme
B. Null enzyme
C. Zymogen
D. Inhibitor
EXPLANATION
Option A is incorrect as an apoenzyme is a protein that forms an active enzyme when it binds with a coenzyme Option B is incorrect as alleles produce an enzyme that has no catalytic activity. Option C is correct as a zymogen is an enzyme which is inactive until another enzyme activates it.  Option D is incorrect as an inhibitor is a substance that binds to enzymes to reduce enzyme activity.

QUESTION: The type of bronchitis that causes no permanent damage to the lungs and lasts for two weeks is known as?
A. Acute bronchitis
B. Chronic bronchitis
C. Coastal bronchitis
D. Intercostal bronchitis
EXPLANATION
Option A is correct as acute means that it happened suddenly and, it does not affect the person for a very long time.

QUESTION: A human cell from the ovary has 22 chromosomes and an X chromosome. It is which of the following?
A. Egg
B. Sperm
C. Somatic cell
D. Gamete
EXPLANATION
Option A is correct as a cell with 22 chromosomes and one sex chromosome will be a haploid cell. If the sex chromosome is X it is female, if Y then male. So it should be an egg.

QUESTION: The Urey-Miller experiment determined which of the following results?
A. DNA replicates by semiconservative replication
B. Cyanobacteria were responsible for the oxygenation of the atmosphere
C. The early atmosphere was composed of ammonia and methane
D. Organic molecules can arise from inorganic precursors
EXPLANATION
Option D is correct as the Miller–Urey experiment was a chemical experiment that simulated the conditions thought at the time to be present on the early Earth and tested the chemical origin of life under those conditions. The results showed how organic life could form from inorganic origins.

QUESTION: Which of the following statement is incorrect for fats containing unsaturated fatty acid?
A. They contain double bond
B. They are lighter than water
C. Their specific gravity is less than 1
D. They are usually solid at room temperature
EXPLANATION
Option D is correct as unsaturated fats have double bonds, which form kinks/bends in the chain, thus causing them not to stack on top of each other easily, so they cant be solid. They are liquid at room temperature and pressure.

QUESTION: From one pyruvate passing through Krebs cycle, how many NADH are formed?
A. 1
B. 2
C. 3
D. 4
EXPLANATION
Option C is correct as one pyruvate forms one Acetyl CoA molecule and from one Acetyl CoA used in one cycle in the Krebs cycle produces three molecules of NADH.

QUESTION: Where does the human body store spermatozoa?
A. Ejaculatory duct
B. Seminal vesicle
C. Seminiferous tubules
D. Epididymis
EXPLANATION
Option D is correct as epididymis is a long coiled tube where sperm is stored in the testicles, and the epididymis transports sperm to the vas deferens.

QUESTION: Under microscopic examination, which cellular structure would differentiate a plant cell from an animal cell?
A. Nucleus
B. Cell membrane
C. Cytoplasm
D. Cell vacuole
EXPLANATION
Option D is correct as plant cells usually have only one ore two large vacoules in the centre. Animal cells have multiple small vacoules spread across the cytoplasm.

QUESTION: In mammals, which type of phenotypic expression will show recessive traits more frequently in males than females?
A. Incomplete dominance
B. Complete dominance
C. Codominance
D. X-linked
EXPLANATION
Option D is correct as males have an X and a Y chromosome, and if the recessive alleles are linked to the X chromosome, then it will be expressed in the phenotype. If a female has an X linked recessive allele, then unless the other X chromosome has a recessive allele, the gene wont express itself in the phenotype.

QUESTION: A defective virus that needs the unrelated help of virus to infect the same host cell in order to provide essential functions is:
A. Satellite virus
B. HAV
C. HCV
D. HIV
EXPLANATION
Option A is correct as a satellite virus is a subviral agent that depends on the coinfection of a host cell with a helper virus for its replication.

QUESTION: The auditory relay center is found in:
A. Corpus callosum
B. Hindbrain
C. Forebrain
D. Midbrain
EXPLANATION
Option D is correct as the midbrain main function is control of movement, especially of the eye and auditory and visual processing.

QUESTION: Which the following is not the unique features of synovial joint?
A. Articular capsule
B. Articular cartilage
C. Synovial fluid
D. Fibrocartilage
EXPLANATION
Option D is correct as fibrocartilage is found in the intervertebral discs as well as some synovial joints.

QUESTION: Which brain part is responsible for our basic and primitive emotions?
A. Limbic system
B. Thalamus
C. Hypothalamus
D. Cerebrum
EXPLANATION
Option A is correct as the limbic system is a group of interconnected structures located deep within the brain which is responsible for our behaviour and emotions. Option B is incorrect as the thalamus has the role of relaying motor and sensory signals, as well as regulation of consciousness and alertness. Option C is incorrect as the hypothalamus has the role of keeping internal bodily functions in balance. Option D is incorrect as the cerebrum controls muscle function as well as speech, thought, reading, writing and learning.

QUESTION: All of the following statements are true regarding the attachment or adsorption of the virion to the host cell EXCEPT that:
A. For naked virions, the surface capsid proteins are responsible for binding to a specific cell receptor
B. For enveloped viruses, the spikes are responsible for binding to a specific cell receptor
C. Cell lacking a receptor for a specific virus is not infected by that virus
D. All of the above
EXPLANATION
Option D is correct as naked virions with no envelope directly bind to a host cell with its capsid. An enveloped virus has spikes which bind to receptors on the host cell. If the cell lacks a receptor, then the virus cant infect it.

QUESTION: A motion with constant velocity can be represented on a displacement-time graph by?
A. AA horizontal line
B. A curve line with a decreasing gradient
C. A straight line with a constant gradient
D. A* curve line with increasing gradient
EXPLANATION
Option C is correct as a constant gradient means there is a constant change in displacement over change of time so velocity is constant.

QUESTION: SI Unit of current is?
A. Ampere
B. Volt
C. Joules
D. Watt
EXPLANATION
Option A is correct as current is measured in Amperes (A).

QUESTION: In a stationary wave, the distance between adjacent antinodes is equal to?
A. λ
B. 2λ
C. λ /2
D. λ /4
EXPLANATION
Option C is correct as antinodes are points on a wave with maximum displacement, found in the centre of half a wave. The distance between two antipodes is, therefore, two-fourths of a wavelength.

QUESTION: From the following properties of a wave, the one that is independent of the other three is its?
A. Amplitude
B. Frequency
C. Wavelength
D. Time period
EXPLANATION
Option A is correct as amplitude is not affected by the frequency, wavelength, or time period. The previous three are related by the equation v = f × wavelength. Amplitude is changed by the loudness or power of the wave.

QUESTION: Wave nature of electron is similar to?
A. Proton
B. Beta rays
C. Gamma rays
D. All of these
EXPLANATION
Option B is correct as beta rays consist of beta particles which are basically the same as electrons, I.e negligible mass and negative charge equal to the value of charge of one proton.

QUESTION: The angle subtended at the center of a circle by an arc equal to the radius of the circle is?
A. One degree
B. One rotation
C. One radian
D. None of these
EXPLANATION
Option C is the right answer as one radian is the angle of the arc when the arc is equal to the radius of the circle.

QUESTION: The particle that possesses half-integral spin has?
A. Pion
B. Proton
C. K-meson
D. Photon
EXPLANATION
Option B is correct as fermions have a half-integral spin. Fermions include protons, neutrons, and electrons.

QUESTION: Consider a capacitor that has a 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
Option C is correct because to double the charge; you will need to increase the area of plates so that it holds more charge.  Thus charge does not decide capacitance. Capacitance decides how much charge a capacitor can hold.  You can not double the capacitance by giving a double charge. This extra charge will get wasted.

QUESTION: Kilowatt-hour(kWh) is a unit of?
A. Power
B. Energy
C. Current
D. Resistance
EXPLANATION
Option B is correct as energy=power×time. SI unit of power is the watt (W) thus the kWh is a unit for energy.

QUESTION: The principle behind the working of cathode ray oscilloscope is?
A. Oscillation
B. Half-wave rectification
C. Full wave rectification
D. None of these
EXPLANATION
Option B is correct.

QUESTION: The principle of transformer is?
A. Mutual inductance
B. Self induction
C. Motional emf
D. None of these
EXPLANATION
Option A is correct as when a transformers primary coil has an AC flowing through it; magnetic flux surrounds the conductor in proportion to the amount of current. The expanding and contracting flux cuts the secondary coil and induces a voltage in it. This is mutual inductance.

QUESTION: A horse is pulling a cart of mass 50 kg in the horizontal direction. If the distance traveled is 20 m, then what will be the work done by the horse?
A. 1000 J
B. -l000 J
C. 12/31 J
D. 500 J
EXPLANATION
Work done, W is equal to the force f times the distance d, or W = fd. W = 50 x 20. W = 1000 J.

QUESTION: x-rays can be deflected by?
A. Electric field
B. Magnetic field
C. Both a & b
D. None of these
EXPLANATION
Option D is correct as X-rays are electromagnetic waves and are not charged, so they cannot be affected by electric fields or magnetic fields.

QUESTION:  Which principle is used in solar cells?
A. Momentum
B. Charge
C. Mass
D. All of these
EXPLANATION
Fact.

QUESTION: Which of the following process is reversible ?
A. Transfer of heat by radiation
B. Electrical heating by nichrome wire
C. Transfer of heat by conduction
D. Isothermal compression
EXPLANATION
Option D is correct as isothermal expansion or compression is reversible so long as the piston motion is sufficiently slow such that at each instant the gas temperature and pressure are uniform and conform to ideal gas law.

QUESTION: A uniform chain of length 2 m is kept on a table such that a length of 60 cm hangs freely from the edge of the table. The total mass of the chain is 4 kg. What is the work done in pulling the entire chain on the table?
A. 7.2 J
B. 3.6J
C. 120 J
D. 1200 J
EXPLANATION
Option B is correct as we first find the mass of 60 cm of chain. 2m of chain= 4 kg so 0.6m =1.2 kg. 1.2 kg has to be pulled up 30cm high against gravity (as the centre of mass of the chain hanging is in the middle of the chain), so mass×gravitational force×height, 1.2×10×0.3=3.6J.

QUESTION: Which isotope has the highest momentum when moving with the same velocity?
A. Protium
B. Deuterium
C. Tritium
D. All of these have the same momentum
EXPLANATION
Option C is correct as tritium is the heaviest isotope of water with two neutrons and 1 proton Thu travellings will have more momentum travelling at the same speed as the other two isotopes. Momentum=mass×velocity.

QUESTION: Which of the following cannot determine the state of thermodynamic system?
A. P and V
B. P and T
C. T and V
D. P and R
EXPLANATION
Option D is correct as to find the state of the thermodynamic system, we need P, V, or T. If we have any two, we can find the state. If we only have one, then it is not possible to find the state of the system.

QUESTION: Force on a moving charge in a uniform magnetic field will be maximum when angle between v and B is ?
A. Zero
B. 30
C. 60
D. 90
EXPLANATION
Option D is correct as the formula to find force in a magnetic field is F=Bqv Sin(theta). Sin value is maximum when the angle is 90⁰ thus force will be maximum at 90⁰.

QUESTION: Three charges+ 3q + q and Qare placed on a straight line with equal separation. In order to make the net force on q to be zero, the value of Q will be?
A. 3q
B. 2q
C. 4q
D. 5q
EXPLANATION
Option A is correct as to balance out the force on q on either side Q must be equal to 3q.

QUESTION: A square coil of side length 2 mm is placed in the x-y plane and in uniform magnetic field 0.1 T. Find total flux through the coil?
A. 1.6 Wb
B. 0.16 Wb
C. 16 Wb
D. 0 Wb
EXPLANATION
Magnetic flux=BA cos theta As the question states, it is placed in the ‘x-y plane’, implying that the angle between the magnetic field and the coil is 90 degrees. This would make the value of cos theta Zero. Hence the magnetic flux would also be zero

QUESTION: Which of the following waves cannot be polarized?
A. Radio waves
B. Ultrasound
C. Ultraviolet
D.  X-rays
EXPLANATION
Ultrasound waves are longitudinal in nature, hence they cannot be polarized.  Only transverse waves like electromagnetic waves can be polarized.

QUESTION: In step up transformer?
A. Vs/Vp =1
B. Vs< Vp
C. Vs=Vp
D. Vs> Vp
EXPLANATION
Step-up transformer is a transformer that increases the voltage from primary to secondary. Hence Vs>Vp.

QUESTION: Acceleration of a moving train when it starts its motion is?
A. Negative
B. Zero
C. Positive
D. Infinite
EXPLANATION
The acceleration of a train when it starts its motion will always be positive. a=(v-u)/t Since ‘v’ (final velocity) would be more than when it was stationary ‘u’ (initial velocity)

QUESTION: An a.c. generator consists of a coil of 50 turns and an area of 2.5 m2 rotating at an angular speed of 60 rad s-1 in a uniform magnetic field of 0.3 T between two fixed pole pieces. What is the flux through the coil, when the current is zero?
A. Maximum
B. Minimum
C. Zero
D. Independent
EXPLANATION
When the current is zero, the induced EMF would also be zero. And if the EMF is zero then naturally magnetic flux would also be zero, since EMF= rate of change of flux

QUESTION: T1 and T2 are the half-lives of two radioactive elements of decay constant A, and Az respectively then the value of T,/Tz is .......?
A. λ 2=λ 1
B. λ 1λ 2
C. λ 1/.λ 2
D. λ 2/λ 1
EXPLANATION
T = 0.693/λ. Hence T1=0.693/λ1 and T2=0.693/λ2 So the value of T1/T2 would be (0.693/λ1)/(0.693/λ2), which would equate to λ2/λ1.

QUESTION: Consider a charge q is placed in a region where both electric and magnetic fields are present. The charge will experience?
A. Both electric and magnetic forces
B. Only electric force
C. Only magnetic force
D. No force at all
EXPLANATION
As the question states, ‘a charge is placed’, implying that the charge is stationary. It will only experience the electric field, it is because the electric field only depends on the magnitude of charge and electric field intensity given by F=q*E. The magnetic force that a charge experiences is given by F=q*v.B if v=0, then the magnetic force will be zero, and the charge experiences electric force only.

QUESTION: The linear momentum of a 3 MeV photon is?
A. 0.01 eV s m-1
B. 0.05 eV s m-1
C. 0.03 eV s m-1
D. 0.04 eV s m-1
EXPLANATION
Energy (E) of photon of 3 MeV = 3 x 106 eV Linear momentum of photon p = E/c, where c is the speed of light in a vacuum So p= (3 x 106)/(3 x 108) which would equate to 0.01 eV s m.-1

QUESTION: Which of the constants is not related to radiation?
A. Boltzmann
B. Planck
C. Solar constant
D. All of these options are correct
EXPLANATION
The Boltzmann constant is the proportionality factor that relates the average relative kinetic energy of particles in a gas with the thermodynamic temperature of the gas. Plancks constant relates the energy in one quantum (photon) of electromagnetic RADIATION to the frequency of that RADIATION. The solar constant is a flux density measuring means solar electromagnetic RADIATION per unit area.  Hence Option A would be the correct option.

QUESTION: Which one of the following is a disadvantage of a potentiometer over a voltmeter?
A. It can measure the internal resistance of a cell
B. It can measure the e.m.f. of a cell
C. It is heavy and not portable
D. It can measure accurately very small PD. of the ord of a few microvolts
EXPLANATION
options A, B, and D would rather be the advantages or uses of potentiometers, hence considering all the options, option C would be the disadvantage of potentiometers as potentiometers are, in fact, heavy and not portable compared to voltmeters.

QUESTION: For a parallel plate capacitor, the energy density is?
A. ½ ErEO E
EXPLANATION
Energy density is the total energy per unit volume of the capacitor, as the electrostatic energy stored in a parallel plate capacitor is U=½ CV^2 for a parallel plate capacitor, C=(ε0εrA)/d and V = Ed; so, U=½ (ε0εrA/d)(Ed)^2=½ ε0εrE^2(Ad), Where Ad = Volume of the capacitor (V). Then Energy density U/V = ½ ε0εrE^2.

QUESTION: Work done by the magnetic force on a charged particle in presence of a perpendicular magnetic field is?
A. Positive
B. Zero
C. Negative
D. None of these
EXPLANATION
The magnetic force acts in such a way that the direction of the magnetic force and velocity are always perpendicular to each other.  If force and velocity are perpendicular, force and displacement are also perpendicular; thus, W= FS cos q, if q = 90, work done will be zero.

QUESTION: When deuterium and tritium fuse together they form?
A. Atom
B. U atom
C. N atom
D. He atom
EXPLANATION
Deuterium–tritium fusion is a type of nuclear fusion in which one deuterium nucleus fuses with one tritium nucleus, giving one helium nucleus, one free neutron, and energy.

QUESTION: Peak voltage in the output of half-wave rectifier is l0V so de component of the output voltage is?
A. 10√ 2
B. 10/√ 2
C. 10/π
D. 10π
EXPLANATION
Through our knowledge, we know the peak voltage is fed with a sinusoidal signal without a filter which is 10V. Here we have a Half wave rectifier, so it nullifies one of the cycles of the input, and only one-half cycle is present in the output. The output DC component of the half-wave rectifier is given by the formula, Vdc = peak voltage (V0) / πVdc = 10/ π V.

QUESTION: The units of angular velocity are similar to?
A. Angular displacement
B. Angular acceleration
C. Angular frequency
D. None of these
EXPLANATION
Angular Velocity is defined as the rate of change of angle with respect to time, leading to the equation 𝜔=Δ𝜃/Δ𝑡, where 𝜃 is the angle measured in radians and t is time measured in seconds (s). This yields units of Angular velocity to be radians/s.

QUESTION: Which of the following as a spin motion?
A. The motion of the planets around the sun
B. The moment of an electron around the nucleus
C. The motion of the moon around the Earth
D. The daily rotation of Earth causes day and night
EXPLANATION
There are two types of circular motions; orbital motion and spin motion.  Orbital motion; the axis of rotation does not pass through an object. Spin motion; the axis of rotation passes through an object.  A, B & C are Orbital Motions. D is Spin motion as the earth rotates about its own axis to complete one full day.

QUESTION: The points which are in phase are separated from one another through a distance of?
A. 1 wavelength
B. 1.5 wavelength
C.  0.5 wavelength
D. 2.5 wavelength
EXPLANATION
Two points in the phase are separated by a whole (1; 2, 3; …) a number of multiple whole wave cycles or wavelengths. The points in the phase do not have to be crests or troughs, but they must be separated by a complete number of wavelengths. Since option A is the only option with a complete whole number of wavelengths, that is the correct option.

QUESTION: The resistance of a human body is about?
A. 12 ohm
B. 120 ohm
C. 120K ohm
D. 120M ohm
EXPLANATION
Human resistance is about 10,000 ohms on the high side and as little as 1,000 ohms if the person is wet. The Human body has different resistances; when dry, resistance is 100,000 ohms.  The human bodys resistance to current flow varies depending on: internal and external moisture, exposed sub-epidermal tissue, and skin thickness. Therefore, the value may fluctuate, so the approximated answer is option C; 120K ohms.

QUESTION: The stationary waves can be set up on the string only with the frequencies of harmonic series determined by?
A. The tension, length and mass per unit length of the string
B. The tension and mass per unit length of the string only
C. The length and mass per unit length of the string only
D. The tension and length of the string only
EXPLANATION
The harmonics are multiples of the fundamental frequency. And fundamental frequency=(1/2l) x under-root(F/m) Where l is the length of the string F is the tension and m is the mass per unit length of the string.

QUESTION: Angular velocity cannot be?
A. Zero
B. Negative
C. Infinite
D. Linear
EXPLANATION
Angular velocity can be zero when an object is stationary. Angular velocity can be negative when an object is moving clockwise or when the angular displacement is decreasing.  Angular velocity CAN NOT be infinite.  According to the formula, angular velocity is equal to v/r and for angular velocity to be infinite radius it has to be zero.  Which is not possible. Angular velocity can also be ‘equal’ to the linear velocity if the radius was 1 meter according to the formula angular velocity=v/r

QUESTION: The condition for the validity under Ohms law is that?
A. Resistance must be uniform
B. Current should be proportional to the size of the resistance
C. Resistance must be wire wound type
D. Temperature at the positive end should be more than the temperature at negative end
EXPLANATION
Ohm’s law states that the voltage or potential difference between two points is directly proportional to the current or electricity passing through the resistance and directly proportional to the resistance of the circuit.  This is given by I∝V or V∝I   IV=Constant.  The formula for Ohm’s law is V=IR. It is imperative for the temperature to be constant and the resistance to be uniform for ohms law to be valid. Hence option A.

QUESTION: The primary and secondary powers of a transformer are 200W and 100 W respectively, the efficiency of a transformer is:
A. 50%
B. 1
C. 20%
D. 10%
EXPLANATION
The formula for the efficiency of a transformer is given by,  Efficiency η = Output power / input power X 100 = output power / output power + losses X 100 .  primary power is the input power, and secondary is the output power  Efficiency η = 100W/200W X 100  Efficiency η = ½ x 100 Efficiency η = 50%

QUESTION: If the potential difference across the two plates of a parallel plate capacitor is doubled, then the energy stored in the capacitor would be?
A. Remains same
B. Two times
C. Four times
D. Three times
EXPLANATION
A capacitor is a device that can store energy in the form of electrical energy. Energy stored in the capacitor is given by W= ½ CV2, where C is capacitance and V is voltage.  If V is doubled, we can rewrite the equation as  WNEW= ½ C (2V)2 WNEW= ½ C 4 V2 WNEW= 4 W Consequently, the energy stored will increase by 4 times that stored originally when the V is doubled.

QUESTION: A disc of radius 2 m and mass of 100 kg roll on a horizontal surface, its center of mass has speed of 2 cm/s, how much work is needed to stop it?
A. 1J
B. 3J
C. 30 J
D. 2 J
EXPLANATION
Work done to stop the disc = change in total kinetic energy of disc  Final KE = 0  Initial KE = Translational K.E + Rotational K.E Initial KE= ½mv2 + ½ Iω2  Initial KE= ½mv2 + ½ x mR2 / 2 x (v/R)2 Initial KE=½mv2 + ¼ mv2 = ¾ mv2 Initial KE= =¾ ×100× (20×10-2)2 ΔKE =3J

QUESTION: Let L be the light source. Its intensity at the distance of 3x from Lis I. What is its intensity of light at a distance of 2x from the source of light?
A. 9l/4
B.  3l / 2
C. 4l/9
D. 2l / 3
EXPLANATION
Inverse square law will be used.  I1/I2=d2^2/d1^2. I/I2=((2x)^2)/((3x)^2) Which would equate to 9I/4.

QUESTION:  SI unit of equivalent dose is?
A. Gray
B. Radiation
C. Sievert
D. Rem
EXPLANATION
The SI unit of measure for equivalent dose is the sievert, defined as one Joule per kg.

QUESTION: A full-wave rectifier is operating from 50Hz mains. The fundamental frequency of ripple will be?
A. 100 Hz
B. 25Hz
C. 50Hz
D. 200Hz
EXPLANATION
Full-wave rectification is a type of rectification in which output is obtained for both halves of a.c. Whereas, the frequency of the output is double that of the input. In a full-wave rectifier, the frequency of the ripple is double that of the main frequency. Hence ripple frequency = 100 Hz.

QUESTION: A string 2m long is used to whirl a 200g stone in a horizontal circle at a speed of 2m/s. Find the tension in the string.
A. 0.4 N
B. 1.4 N
C. 2.4 N
D.  3.4 N
EXPLANATION
tension or force in the string, F=(mv^2)/r  Where m=200g=0.2kg v=2 m/s and r= 2m Add in the values F=(.2x2^2)/2= 0.4N

QUESTION: A car travels 30 m toward the east, then it takes a turn and travels 40 m towards the west. It takes 50 seconds. Its average velocity?
A. -10 m/s
B. -1/5 m/s
C. 7/5 m/s
D. -5 m/s
EXPLANATION
velocity=displacement per time Displacement would be 30-40=-10m since the car first travels 30m towards the east and then 40m towards the west. Time taken was 50 seconds Hence v=-10/50, which equals -1/5 m/s.

QUESTION: A body at temperature T radiates heat according to relation?
A. T^ -2
B. T^ 4
C. T^ -4
D. None of these
EXPLANATION
Stefans formula would be used here, which is as follows. Hence the correct option would be B, T^4.

QUESTION: The shortest distance between two points on a traveling wave that has a phase difference of (pi/3) is 5 cm. If the wave has a frequency of 500 Hz, what is the speed of the wave?
A. 300 m/s
B. 150 m/s
C. 300 cm/s
D. 150 cm/s
EXPLANATION
Phase difference = 2π/λ × path difference. Δϕ=2π​/λ ×Δx Δx = λ/2π​ ×Δϕ --- eq (i) Also, λ= v/n — eq(ii) Now, from Eqs. (i) and (ii), we get Δx= v​/2πn × Δϕ, where x is the distance between two points, v speed of the wave, n is the frequency of the wave, and ϕ is phase difference. Δx = v​/2πn × Δϕ  5x10-2 = v / 2π x 500 × (pi/3) v = 150m/s.

QUESTION: In which of the following processes the heat is neither absorbed nor released by a system?
A. Isochoric
B. Isothermal
C. Adiabatic
D. Isobaric
EXPLANATION
In an adiabatic process there is no exchange of heat. Hence option C is the correct answer.

QUESTION: The transformer laminations are insulated from each other by?
A. Mica strip
B. Paper
C. Thin coating of Varnish
D. Any of the above
EXPLANATION
These laminations are insulated from each other by a thin coat of varnish or paper to increase the effective resistivity of the core, thereby increasing the overall resistance to limit the flow of the eddy currents.

QUESTION: In pair production .................... are produced?
A. Positron & electron
B. Photons
C. Electron & neutron
D. B & C are correct
EXPLANATION
pair production, as implied by the name, is the production of a position and electron pair when a photon of high energy (gamma ray) passes by a heavy nucleus. The electron positron pair satisfies the energy, momentum and charge distribution possessed by the photon.

QUESTION: The unstable atom means?
A. Electrons are increasing
B. Protons are increasing
C. Neutrons are increasing
D. Any of these
EXPLANATION
Multi electronic species are unstable, it prefers to lose electrons and form a stable octet or duplet; a higher proton and neutron number means a heavier nucleus which is naturally radioactive, i.e. naturally unstable.  An unstable atom also has excess internal energy, with the result that the nucleus can undergo a spontaneous change (change in the number of protons and/or neutrons) towards a more stable form.

QUESTION: If a cell of emf 2V and internal resistance 0.5 ohm is connected across a resistance R, the current that flows is the same as that when a cell of emf 1.5 V and internal resistance 0.3 ohms is connected across the same resistor. Then R= Ohm.
A. 0.3
B. 0.6
C. 0.5
D. 0.75
EXPLANATION
Figure 1 describes the first cell and figure 2 describes the second cell, both carrying the same current i. i is the circuit current and to find R  Using ohms law for figure 1.  V=IR  V= i Req1 , where i is the circuit current and Req1 is the resistance of the first cell.  Req1 = 0.5 + R (since they are in series the resistance are added) V= i Req1 2= i (0.5 + R) i = 2 / 0.5 + R — eq1 Using ohms law for figure 2. V=IR   V= i Req2I, where i is the circuit current, and Req2 is the resistance of the second cell.  Req = 0.3 + R (since they are in series the resistance are added) V= i Req2  1.5 = i (0.3 + R) i= 1.5 / 0.3 + R —- eq2  Equating both eq1 and eq2  2 / 0.5 + R = .5 / 0.3 + R 0.6 + 2R = 0.75 + 1.5R 0.5R = 0.15 R = 0.15/0.5  R=0.3 ohms

QUESTION: Fact Checking: Fact 1: Some pens dont write  Fact 2: Only blue pens write  Fact 3: Some writing utensils are pens  If the above three statements are facts then which of the following statement will also be a fact?  I. Some writing utensils dont write  II. Some writing utensils are blue  Ill. Some blue writing utensils dont write
A. Only Ill
B. Only I and II
C. Only I
D. Only Ill and II
EXPLANATION
Since some pens dont write, some writing utensils dont write(statement I). Since there are blue pens and since pens are writing utensils, some writing utensils are blue(statement II).  There is not enough information to support statement III.

QUESTION: Dependent causes/ Independent causes: Statement: There is an unprecedented increase in the number of young unemployed in comparison to the previous year.  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: Statements and Actions: Statement There has been an unprecedented increase in the number of requests for seats in most of the long-distance trains during the current holiday season. I. The Statement There is an unprecedented increase in the migration of villagers to urban areas as repeated crop failure has put them into a precarious financial situation.  Courses of Action  I. The villagers should be provided with alternative sources of income in their villages which will make them stay put.  II. The migrated villagers should be provided with jobs in the urban areas to help them survive. authority should immediately increase the capacity in each of these trains by attaching additional coaches.  II. The people seeking accommodation should be advised to make their travel plan after the holiday.
A. Both of them follows
B. None of them follows
C. Only I follows
D. Only II follows
EXPLANATION
Since there is an ever-increasing demand for berths in certain trains that lead to holiday destinations and government cannot protect them from going to these places. It is the duty of the railway to accommodate all the passengers going, and this can be done by increasing the number of births. Thus, only I follows.

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

QUESTION: Analogies: Aware is to alert as prompus is to:
A. Scarcely
B. Impolitely
C. Bragging
D. Quietly
EXPLANATION
Alert is a synonym of aware so the answer will be a synonym of pompous. Out of the options given to us, only bragging is a synonym of pompous.

QUESTION: Statements and Actions: Statement The availability of imported fruits has increased in the indigenous market and so the demand for indigenous fruits has been decreased.  I. To help the indigenous producers of fruits, the Government should impose high import duty on these fruits, even if these are not of good quality. II. The fruit vendors should stop selling imported fruits. So that the demand for indigenous fruits would be increased.
A. Both of them follows
B. None of them follows
C. Only I follows
D. Only II follows
EXPLANATION
The ideas suggested in both I and II represent unfair means to cut competition.  The correct way would be to devise methods and techniques such that the indigenous producers could produce better quality fruits and make them available in the market at prices comparable with those of the imported ones.  Hence, neither I nor II follows.

QUESTION: Verbal Classification: If a computer has more than one processor, then it is known as:
A. Uni-process
B. Multiprocessor
C. Multi-threaded
D. Both A and B
EXPLANATION
Its a Multiprocessor. UNI Process represents a single process, not about any processor. Multithread represents executing multiple threads, multiprogramming represents a parallel process of several programs

QUESTION: Number Series: look at this series 7,10,8,11,9,12. Which number do you think will be next?
A. 10
B. 13
C. 7
D. 12
EXPLANATION
It is a simple alternating addition and subtraction series. In the first pattern, 3 is added; In the second pattern, 2 is subtracted.

QUESTION: Answer on passage: Four friends in the fifth grade were sharing a pizza. They decided that the oldest friend would get the extra piece.  Zara is two months older than Mohib, who is three months younger than Kiran. Minal is one month older than Mohib. Who should get the extra piece of pizza?
A. Zara
B. Mohib
C. Kiran
D. Minal
EXPLANATION
If Zara is two months older than Mohib, then Kiran is three months older than Mohib and one month older than Zara.  Minal is younger than both Zara and Kiran. Kiran is the oldest.

QUESTION: Verbal Reasoning: Country with the highest Muslim population is __
A. Pakistan
B. Malaysia
C. Indonesia
D. Iran
EXPLANATION
Pakistan- 200,352,754 Muslims Malaysia- approximately 19.5 million Muslims Indonesia- 229.6 million Muslims  Iran- 82,000,000 people Muslims