Shahid Posted July 3 Share Posted July 3 Prepare the PMC Paid Practice Tests Series 2021 with our comprehensive past paper and explanation guide. Gain valuable insights into the exam format, question types, and essential topics covered. Our detailed explanations will help you understand the reasoning behind each answer, allowing you to strengthen your knowledge and improve your performance. Get a head start on your exam preparation and increase your chances of success with our PMC Paid Practice Tests Series 2021 past paper and explanation resource. QUESTION: Choose the correct spelling of the word:A. ArroundB. ArondC. ArundD. Around EXPLANATIONAround is the correct spelling. QUESTION: Gold is ______ precious metal.A. AB. AnC. TheD. No article is required EXPLANATIONA/an and the are articles. They are types of determiners and they go before a noun. Use βaβ before words that start with a consonant sound and βanβ before words that start with a vowel sound. QUESTION: What type of statement is the followng: What is your name?A. DeclarativeB. ImperativeC. InterrogativeD. Exclamatory EXPLANATIONThe statement has a question, therefore it is interrogatory. QUESTION: Choose the correct sentence:A. ali lives in dubai, the United arab emirates.B. Ali lives in dubai, the united arab emirates.C. Ali lives in Dubai, in the United Arab Emirates.D. Ali lives in Dubai, the United Arab Emirates. EXPLANATIONAll proper nouns like names of persons and places must be capitalized. QUESTION: One bad exam result and all her dreams were _______.A. FledB. ShatteredC. FulfilledD. Floating EXPLANATIONSince the results were bad, they would have a bad effect on her dreams thus the word shattered will be chosen. If you are shattered by something, you are extremely shocked and upset about it. QUESTION: Bilal _______ (live) with his brother.A. LivesB. Is livingC. Has livedD. Had lived EXPLANATIONLives is the present continuous form of live. QUESTION: Identify the tense used in the given sentence: Everyone shall be reaching by tomorrow.A. PresentB. PastC. FutureD. None EXPLANATIONThe word shall indicates future tense. QUESTION: Find the error in the sentence:A. Now the time wasB. To escapeC. And he opened the windowD. And jumped out. EXPLANATIONNow the time is would be more accurate as the sentence is in the present tense. QUESTION: What type of statement is the following: I have two sisters.A. DeclarativeB. ImperativeC. InterrogativeD. Exclamatory EXPLANATIONThis sentence is a statement therefore it is a declaration. QUESTION: Each and every member _______ to vote.A. HasB. HaveC. HavingD. Are EXPLANATIONThe word has is used with singular nouns. QUESTION: Select the word that describes block headed:A. DunceB. SmartC. WiseD. Aglie EXPLANATIONDunce is a person who is slow at learning; a stupid person. QUESTION: What is the short form of I have?A. IveB. IveC. lhveD. Ihve EXPLANATIONA 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: Choose the correct spelling of the word:A. DiscribeB. DeskribeC. DescribeD. Diskribe EXPLANATIONTo describe something means to give a detailed account in words. QUESTION: One of the students said, _______ professor is late today.A. AB. AnC. TheD. No article is needed in this scenario EXPLANATIONThe definite article the is used before singular and plural nouns when the noun is specific or particular. QUESTION: His bag was quite _____ so I easily carried it to his room.A. CheapB. HeavyC. LightD. Short EXPLANATIONSince the bag was light, it was easy to carry. QUESTION: I advised her _______ drink it.A. DontB. Not toC. To notD. To dont EXPLANATIONThe preposition must be placed after not. QUESTION: Find the error in the following sentence:A. As an officerB. He not only wasC. Competent butD. Also honest. EXPLANATIONThe orientation of the segment, He not only was__, is inaccurate. The correct form would be He was not only___. QUESTION: The book is about _______ man who lives on _______ small island.A. A, anB. A, aC. A, theD. An, a EXPLANATIONA/an and the are articles. They are types of determiners and they go before a noun. Use βaβ before words that start with a consonant sound and βanβ before words that start with a vowel sound. QUESTION: Sam ______ in the garden now.A. DigsB. DiggingC. Is digingD. Is digging EXPLANATION-ing makes the verb in present continuous form. QUESTION: If mountains are _________ of trees, rains will soon wash the fertile topsoil down the slope to end up as useless silt below.A. DeforestedB. AfforestedC. StrippedD. Shortage EXPLANATIONStripped means taken away. QUESTION: In which of the following does no net gaseous exchange take place between leaves and the atmosphere?A. Day B. NightC. Dawn and DuskD. Midnight EXPLANATIONAt dawn and dusk, the intensity of light is low. At this moment the amount of oxygen released from photosynthesis is equal to the amount of oxygen used in respiration. Similarly, the amount of carbon dioxide released from respiration is equal to the amount of carbon dioxide in photosynthesis. It is called Compensation Point. QUESTION: Competitive inhibition can be overcome by using:A. Low concentration of substrateB. High concentration of inhibitorC. Moderate concentration of inhibitorD. High concentration of substrate EXPLANATIONCompetitive inhibition can be overcome by adding more substrate to the reaction, which increases the chances of the enzyme and substrate binding. As a result, competitive inhibition alters only the Km, leaving the Vmax the same. QUESTION: Which of the following shows radial symmetry?A. ChordatesB. AnnelidsC. CnidarianD. Round worms EXPLANATIONRadial symmetry means the organisms that can be divided into two equal parts so the answer is option C. Cnidarian is the answer because members of the group include jellyfish, sea anemones, and hydra. They are a diverse group, but all organisms in this phylum have radial symmetry and can be divided into equal parts through a central axis just like a pie. QUESTION: The branch that deals with the study of viruses is known as?A. EntomologyB. BacteriologyC. VirologyD. Epidemiology EXPLANATIONThe branch which deals with the study of viruses is Virology. QUESTION: Which statement is incorrect?A. In short-day plants, red light prevents floweringB. In long-day plants, far-red light promotes floweringC. Leaf unrolling occurs in grassesD. Henbane is a short-day plant EXPLANATIONA, B and C are correct. Henbane is a long-day plant, meaning that it requires light for a duration longer than a critical period for flowering to occur. QUESTION: Outbreeding increases which of the following?A. HomozygosityB. HeterozygosityC. Gene linkageD. Gene pool EXPLANATIONThe answer to this question is option B which is Heterozygosity because, with outbreeding enhancement, heterozygosity increases the fitness of a population and remarks potential deleterious recessive alleles. Studies in several species demonstrate that outbreeding between populations has positive effects on traits that influence fitness. In many cases, when two closely related species are hybridized, the offspring are superior to at least one of the parental species. QUESTION: A neuron located in the central nervous system that projects its axon outside the CNS is called:A. Motor nerveB. Sensory nerveC. Both Options A and B are correctD. Mixed nerve EXPLANATIONMotor neurons (also referred to as efferent neurons) are the nerve cells responsible for carrying signals away from the central nervous system towards muscles to cause movement. QUESTION: A surfactant is essential for:A. Efficient gas exchangeB. Maintaining structural integrity of alveoliC. Both Options A and B are correctD. None of these options is correct EXPLANATIONSurfactants are compounds that lower the surface tension between two liquids, between a gas and a liquid, or between a liquid and a solid. The main function of surfactant is to lower the surface tension at the air/liquid interface within the alveoli of the lung. This is needed to lower the work of breathing and to prevent alveolar collapse at end-expiration. QUESTION: Mating between relatives is called which of the following?A. ExbreedingB. BreedingC. InbreedingD. Outbreeding EXPLANATIONBreeding refers to the mating and production of offspring by animals. Inbreeding refers to the mating of related individuals. Outbreeding refers to matings between individuals from different populations, subspecies, or species. QUESTION: In cocci, three plane division results in the formation of sarcine which is a?A. Cube of 8 cocciB. Square of 4 cocciC. Irregular structureD. Triangular 6 cocci EXPLANATIONSarcina is a genus of gram-positive cocci bacteria in the family Clostridiaceae. The genus takes its name from the Latin word sarcina, meaning pack or bundle, after the cuboidal (2x2x2) cellular associations they form during division along three planes. QUESTION: An enzyme without its cofactor is called ______.A. CoenzymeB. ApoenzymeC. HoloenzymeD. Proenzyme EXPLANATIONAn inactive enzyme without the cofactor is called an Apoenzyme, while the complete enzyme with cofactor is called a Holoenzyme. QUESTION: Cellulose is the major component of?A. Primary wallB. Secondary wallC. Middle lamellaD. All of these options is correct EXPLANATIONCellulose gives strength and rigidity to the cell. It makes the wall of plant cells. It is present in walls that are thinner and less rigid than those of cells that have stopped growing. a) Primary wall β It is composed mainly of cellulose. It has higher cellulose content than any other cell walls. b) Secondary wall β It is mainly composed of hemicellulose and pectin. c) Middle lamella β It is mainly composed of pectins. QUESTION: Aschelminthes is also known as which of the following?A. ProtozoansB. EumetazoaC. Protoctist ancestorsD. Nematodes EXPLANATIONThe Aschelminthes (also known as Aeschelminthes, Nemathelminthes, Nematodes), closely associated with the Platyhelminthes, are an obsolete phylum of pseudocoelomate. The phylum aschelminthes are commonly called roundworms. They are called so because their body appears circular in the transverse cross-section. QUESTION: Genes that influence height in humans are:A. CodominantB. EpistaticC. PolygenesD. Pleiotropic EXPLANATIONOption A: Both alleles of a gene are expressed equally and independently in the Heterozygous condition. Offspring shows phenotype of both the parents. Option B: One gene suppresses the expression of another gene that is located at a different locus. Option C: Polygenes control continuously varying traits, which are controlled by alleles of two or more separate genes located at different loci. The genes are called polygenes. In humans, skin color, height, and intelligence are examples of polygenic traits. Option D: Pleiotropy refers to multiple effects of a single gene. QUESTION: Example of convergent evolution is:A. Forelimbs of man and batB. Wings of birds and insectsC. Darwins finchesD. All of above options are correct EXPLANATIONIn evolutionary biology, convergent evolution is defined as the process whereby distantly related organisms independently evolve similar traits to adapt to similar necessities. For example, sharks and dolphins look relatively similar despite being entirely unrelated. Sharks are egg-laying fish with the deadly ability to sniff out blood in the water, while dolphins are curious mammals that navigate by making clicking sounds and listening for their echoes. This is due to the different organisms living in the same selection pressures which select for the same trait(s) causing the features of the different species to converge despite not having any common ancestral lineage. Divergent evolution, on the other hand, occurs from a common ancestor where the descendants attain different traits since different species are subject to different selection pressures, perhaps due to migration to distinct places, for example. QUESTION: The final acceptor of electrons in the respiratory chain is?A. NADHB. Cytochrome a3C. WaterD. Oxygen EXPLANATIONIn cellular respiration, oxygen is the final electron acceptor. Oxygen accepts the electrons after they have passed through the electron transport chain and ATPase, the enzyme responsible for creating high-energy ATP molecules. QUESTION: The internal buds are known as which of the following:A. SpiculesB. ChoanocytesC. GemmulesD. Both Options A and B are correct EXPLANATIONSpicules are the structural components of a sponge, or the bricks, and the shapes, sizes, and composition are unique for each species. Choanocytes are the flagellated cell with a collar of protoplasm at the base of the flagellum, numbers of which line the internal chambers of sponges. Gemmules are a tough-coated dormant cluster of embryonic cells produced by a freshwater sponge for development in more favourable conditions. QUESTION: Darwins theory mainly focuses on:A. Origin of lifeB. How organs extinctC. How new species ariseD. How organisms form EXPLANATIONCharles Darwins theory of evolution had three main components: that variation occurred randomly among members of a species; that an individuals traits could be inherited by its progeny; and that the struggle for existence would allow only those with favorable traits to survive. QUESTION: Which of the following bacteria possesses a spherical shape?A. Bacillus anthracisB. Escherichia coliC. Spirillum minusD. Staphylococcus aureus EXPLANATIONCoccus (plural cocci) is a spherical-shaped bacterium. QUESTION: The spent energy in the form of ADP is regenerated by mitochondria into which of the following form?A. AMPB. ATPC. ADPD. All of these options are correct EXPLANATIONMitochondria are membrane-bound organelles, and those membranes function for the purpose of mitochondria, which is essential to produce energy. That energy is produced by having chemicals within the cell go through pathways. And the process of that conversion produces energy in the form of ATP because phosphate is a high-energy bond and provides energy for other reactions within the cell. So the mitochondrias purpose is to produce that energy. QUESTION: What are T-Cells and their role in HIV infection?A. Type of lymphocytesB. Present in blood and work as the defence systemC. They kill the foreign invaderD. All of these options are correct EXPLANATIONA type of white blood cell, T-cells are part of the immune system and develop from stem cells in the bone marrow. They help protect the body from infection and may help fight cancer. They are also called T lymphocyte and thymocyte. QUESTION: Reflex action is a type of?A. Voluntary actionB. Involuntary actionC. Saltatory conductionD. None of these options is correct EXPLANATIONA reflex action is an automatic (involuntary) and rapid response to a stimulus, which minimizes any damage to the body from potentially harmful conditions, such as touching something hot. Reflex actions are therefore essential to the survival of many organisms. QUESTION: When was the bacteriophage phenomena rediscovered by DHerelle?A. 1918B. 1917C. 1920D. 1990 EXPLANATIONFΓ©lix dHΓ©relle was a French microbiologist. He was a co-discoverer of bacteriophages (viruses that infect bacteria) and experimented with the possibility of phage therapy. DHerelle has also been credited for his contributions to the larger concept of applied microbiology. QUESTION: For respiratory metabolism, a bacterial cell membrane contains:A. ProteinsB. LipidsC. EnzymesD. Chemicals EXPLANATIONBacterial cells lack membrane-bound organelles such as mitochondria. Therefore, the enzymes needed for respiration are present in invaginations of the cell membrane, called Mesosomes. QUESTION: Most carbon dioxide is transported in the form of?A. CarboxyhemoglobinB. Plasma proteinsC. Bicarbonate ionsD. In dissolved form EXPLANATIONCarbon dioxide can be transported through the blood via three methods. It is dissolved directly in the blood, bound to plasma proteins or hemoglobin, or converted into bicarbonate. The majority of carbon dioxide is transported as part of the bicarbonate system. Carbon dioxide diffuses into red blood cells. QUESTION: During which of the following levels of biological organization can natural selection occur?A. GeneB. IndividualC. GroupD. All of these EXPLANATIONNatural selection is the process through which species adapt to their environments. It is the engine that drives evolution. Individuals in a population are naturally variable, meaning that they are all different in some ways. This variation means that some individuals have traits better suited to the environment than others. QUESTION: Flame cells in Planaria constitute the:A. Digestive systemB. Reproductive systemC. Respiratory systemD. Excretory system EXPLANATIONPlanaria are flatworms that live in freshwater. Their excretory system consists of two tubules connected to a highly-branched duct system that leads to pores located all along the sides of the body. The filtrate is secreted through these pores. The cells in the tubules are called flame cells because they have a cluster of cilia that looks like a flickering flame. Flame cells function like a kidney, removing waste materials through filtration. The cilia propel waste matter down the tubules and out of the body through excretory pores that open on the body surface; cilia also draw water from the interstitial fluid, allowing for filtration. QUESTION: Fluid secreted by sertoli cells provides sperms with which of the following?A. Liquid mediumB. ProtectionC. NourishmentD. All of these EXPLANATIONMammalian Sertoli cells are responsible for the formation and secretion of seminiferous tubule fluid (STF) which provides the nutritional and hormonal microenvironment necessary for spermatogenesis. QUESTION: The structure of which bacteriophage resembles a tadpole?A. T2B. T4C. BothD. None EXPLANATIONA T4 bacteriophage is like a tadpole shaped consists of a head, enclosing the nucleic acid, a base plate and a tail having tail fiber. The structure has been adopted from Yap et al. Bacteriophages (phages/viruses) need host bacteria to replicate and propagate. QUESTION: The movement of minerals or water via extracellular pathway is known as?A. SymplastB. ApoplastC. VascularD. None of these EXPLANATIONInside a plant, the apoplast is the space outside the plasma membrane within which material can diffuse freely. The apoplastic pathway is one of the two main pathways for water transport in plants, the other being the symplastic pathway. In apoplastic transport, water and minerals flow in an upward direction via the apoplast to the xylem in the root. QUESTION: Which one of the following is not a feature of the nervous system of Planaria?A. Nuerons are differentiated into sensory, motor and associative neurons.B. Nerves are present.C. No specialized sensory organs are present.D. All of the above. EXPLANATION1. Planaria is a flatworm and belongs to the phylum Platyhelminthes. 2. It is the most primitive animal with a Central Nervous System (CNS) located on the ventral side of the body. 3. Nervous system consists of a mass of cerebral or cephalic ganglion appearing like an inverted U-shaped brain. 4. Ventrally from below the ganglia arise a pair of Ventral Nerve Cords (VNC) or long nerve cords. These are interconnected to each other by transferring nerve or commissure in a ladder-like manner. 5. The PNS include sensory cells arranged in lateral cords in the body. QUESTION: The researcher notices that round seeds occur naturally in the environment. Based solely on this information, what can the researcher conclude about the round phenotype?A. It is dominantB. It is recessiveC. It is wild typeD. Both a and b EXPLANATIONWildtype: a phenotype, genotype, or gene that predominates in a natural population of organisms or strain of organisms in contrast to that of natural or laboratory mutant forms. QUESTION: What molecule would you not expect to find in a retrovirus?A. AdenineB. ThymineC. UracilD. Guanine EXPLANATIONA Retrovirus is a virus that uses RNA as its genetic material. An RNA strand has a backbone made of alternating sugar (ribose) and phosphate groups. Attached to each sugar is one of four bases: adenine (A), uracil (U), cytosine (C), or guanine (G). QUESTION: Ribose is a monosaccharide constituent of many ____A. EnzymesB. CoenzymesC. VitaminsD. Antibiotics EXPLANATIONMetabolically-important species that include phosphorylated ribose include ADP, ATP, coenzyme A, and NADH. QUESTION: The retina is important for ________ of humanA. VisionB. MetabolismC. Muscle contractionD. Muscle twitch EXPLANATIONThe retina is a thin layer of tissue that lines the back of the eye on the inside. It is located near the optic nerve. The purpose of the retina is to receive light that the lens has focused, convert the light into neural signals, and send these signals to the brain for visual recognition. QUESTION: An entire skeletal muscle is surrounded by ________?A. SarcolemmaB. EpimysiumC. Both a and bD. Microtubules EXPLANATIONThe outermost sheath of connective tissue covering each muscle is called Epimysium. Each muscle is made up of groups of muscle fibers called fascicles surrounded by a connective tissue layer called Perimysium. QUESTION: Which of the following best describes a coenzyme?A. Covalently bonded non-protein part of an enzymeB. Cofactor consists of metal ionsC. Loosely bonded non-protein part of an enzymeD. Both A and B EXPLANATIONA coenzyme is an organic non-protein compound that binds with an enzyme to catalyze a reaction. Coenzymes are often broadly called cofactors, but they are chemically different. A coenzyme cannot function alone but can be reused several times when paired with an enzyme. QUESTION: If a cross section of a sarcomere is seen, each myosin is surrounded by how many actin molecules? A. 5B. 6C. 7D. 8 EXPLANATIONThe myosin filament is surrounded by six actin filaments and each actin filament is in turn surrounded by three myosin filaments. This arrangement of the actin and myosin filaments produce a striated appearance to the muscle. QUESTION: How is pyruvate produced in anaerobic conditions?A. Alcoholic fermentationB. Lactic acid fermentationC. RespirationD. Both A and B EXPLANATIONAlcoholic and lactic acid fermentation are two different metabolic pathways of anaerobic respiration. The purpose of both is to replenish NAD+ so that glycolysis can proceed once again, and pyruvate can be formed. QUESTION: The stretch reflex is also known as:A. Stretch reflexB. Spinal reflexC. Golgi tendon reflexD. Myotatic reflex EXPLANATIONThe stretch reflex or myotatic reflex refers to the contraction of a muscle in response to its passive stretching by increasing its contractility as long as the stretch is within physiological limits. QUESTION: The process that secretes insulin from the cell is called:A. EndocytosisB. PinocytosisC. PhagocytosisD. Exocytosis EXPLANATIONEndocytosis is a general term describing a process by which cells absorb external material by engulfing it with the cell membrane. Endocytosis is usually subdivided into pinocytosis and phagocytosis. Exocytosis is the fusion of secretory vesicles with the plasma membrane and results in the discharge of vesicle content into the extracellular space and the incorporation of new proteins and lipids into the plasma membrane. QUESTION: Which cells produce oogonia in ovary?A. Stromal cellsB. Epithelial cellsC. Germ cellsD. Theca cells EXPLANATIONA germ cell is any biological cell that gives rise to the gametes of an organism that reproduces sexually. In many animals, the germ cells originate in the primitive streak and migrate via the gut of an embryo to the developing gonads. QUESTION: Study of fossils is called:A. MammalogyB. PalaeontologyC. HerpetologyD. Ornithology EXPLANATIONMammalogy: The branch of zoology concerned with mammals Herpetology: The branch of zoology concerned with reptiles and amphibians. Ornithology: Ornithology is a branch of zoology that concerns the methodological study and consequent knowledge of birds with all that relates to them. QUESTION: During birth which of following act as birth canal?A. OviductB. OvaryC. UterusD. Vagina EXPLANATIONThe muscular canal that goes from the uterus to the outside of the body. During birth, the baby passes through the birth canal, also called the vagina. QUESTION: Which part of the brain connects the cerebrum with the spinal cord?A. ForebrainB. CerebrumC. CerebellumD. Brainstem EXPLANATIONThe brainstem is the stalklike part of your brain that connects your brain to your spinal cord (column of nerve tissue that runs down your spine). QUESTION: Which of the following are believed to have common origin with annelids?A. NematodesB. ArthropodsC. MolluscsD. None of these EXPLANATIONAnnelids and arthropods have long been considered each others closest relatives, as evidenced by similarities in their segmented body plans. QUESTION: Which statement is incorrect about the Lock and Key Model?A. Specific enzyme can transform only a specific substrateB. Active site of an enzyme is a non-flexible structureC. Active site does not change before during or even after the reactionD. It explains the mechanism of every chemical reaction EXPLANATIONFact QUESTION: Another name for the sex cell is:A. HormoneB. GameteC. ZygoteD. Testicle EXPLANATIONFact QUESTION: The cluster of pouches opened from alveolar ducts is known as:A. BronchiB. BronchiolesC. Pharynx ductD. Alveoli EXPLANATIONThe bronchi are the two large tubes that carry air from your windpipe to your lungs. At the end of the bronchi, the bronchioles carry air to small sacs in your lungs called alveoli. QUESTION: The water splitting step of photosynthesis is called:A. HydrolysisB. ChemiosmosisC. PhotolysisD. Photosynthesis EXPLANATIONPhotolysis of water: Photolysis of water means the splitting of water molecules in the presence of light or photons into hydrogen ions, oxygen and electrons. Any photon with sufficient energy can split the chemical bond of any compound. QUESTION: A chromosome in which a centromere stays at one end is called:A. MetacentricB. TelocentricC. AcrocentricD. All of these EXPLANATIONMetacentric: having the centromere medially situated so that the two chromosomal arms are of roughly equal length. Acrocentric: having the centromere situated so that one chromosomal arm is much shorter than the other. QUESTION: Which of these is the best treatement for osteoarthritis?A. Bed restB. ExerciseC. CastD. None of these EXPLANATIONOsteoarthritis (OA) is the most common form of arthritis. Some people call it degenerative joint disease or βwear and tearβ arthritis. It occurs most frequently in the hands, hips, and knees. QUESTION: Which of the following elements are not found in carbohydrates?A. CB. HC. ND. O EXPLANATIONCarbohydrates are primordial and essential compounds, crucial to the body. They are, at all times, made from Carbon, Hydrogen, and Oxygen, thus the name Hydrated Carbon. QUESTION: The type of bronchitis that causes no permanent damage to the lungs and lasts for two weeks is known as: A. Acute bronchitisB. Chronic bronchitisC. Coastal bronchitisD. Intercostal bronchitis EXPLANATIONChronic bronchitis is long-term inflammation of the bronchi. It is common among smokers. People with chronic bronchitis tend to get lung infections more easily. Acute bronchitis is a contagious viral infection that causes inflammation of the bronchial tubes - these are the airways that carry air into your lungs. When these tubes get infected, they swell and Mucus (thick fluid) forms inside them. This narrows the airways, making it harder for you to breathe. QUESTION: Which of the following is not a viral disease?A. SmallpoxB. MumpsC. TetanusD. Cowpox EXPLANATIONTetanus is an infection caused by bacteria called Clostridium tetani. When the bacteria invade the body, they produce a poison (toxin) that causes painful muscle contractions. QUESTION: Secondary oocyte is ovulated from:A. Corpus luteumB. Graafian follicleC. Primary follicleD. Germinal epithelium EXPLANATIONOvulation is the release of eggs from the ovaries. In women, this event occurs when the ovarian follicles rupture and release the secondary oocyte ovarian cells. After ovulation, during the luteal phase, the egg will be available to be fertilized by sperm. QUESTION: According to the law of independent assortment, what is the possible number of combinations that chromosomes can assort to independently in the gamete?A. 16,777,216B. 2,048C. 4,194,304D. 8,388,608 EXPLANATIONAccording to the law of independent assortment, there are 2n combinations where chromosomes can assort into different gametes. So where n is the haploid number, you get 223=8,388,608. There are 8,388,608 possible combinations of chromosomes when assorting into gametes. QUESTION: The last common ancestor of humans is known to be which of the following?A. Homo neanderthalensisB. LemuroideaC. DromaeosaumsD. Pan troglodytes EXPLANATIONChimpanzees (Pan troglodytes) and bonobos (Pan paniscus) are both our evolutionary closest living relatives. Human and Pan lineages diverged around 7 million years ago, and the chimpanzee and the bonobo branched 1β2 million years ago. QUESTION: Which of the following statements correctly describes how the host cell membrane is changed by viral replication?A. Pores develop.B. Glycocalyx layer is formed.C. Membrane is resynthesizedD. Viral proteins are acquired. EXPLANATIONDuring attachment and penetration, the virus attaches itself to a host cell and injects its genetic material into it. During uncoating, replication, and assembly, the viral DNA or RNA incorporates itself into the host cells genetic material and induces it to replicate the viral genome. QUESTION: Which of the following is a compensation point?A. Leaves respire and utilize O2 and release CO2B. Photosynthesis and respiration occur at the same rate. So there is no net exchange of gases between atmosphere and plantsC. The rate of photosynthesis increases, so does the O2 production, with a net release of oxygen coupled with the uptake of CO2D. The rate of respiration becomes more than the rate of photosynthesis EXPLANATIONThe point reached in a plant when the rate of photosynthesis is equal to the rate of respiration.This means that the carbon dioxide released from respiration is equivalent to that which is taken up during photosynthesis. The compensation point is reached as light intensity increases. QUESTION: Which of the following is not a sterilization method for the control of bacteria?A. RadiationB. FiltrationC. High temperatureD. Antiseptic EXPLANATIONAntiseptics reduce or stop microbial growth, while sterilization removes all microorganisms. QUESTION: Which hormone is procluced mainly by corpus luteum in the ovary following ovulation?A. ProgesteroneB. FSHC. LHD. Chorionic gonadotrophic hormone EXPLANATIONYour corpus luteum produces the hormones estrogen and progesterone. Making progesterone is the corpus luteums most important job, though. Progesterone changes the uterus into a healthy environment for a fetus to develop and grow. QUESTION: According to the induced fit model, what happens when an enzyme-substrate complex is formed?A. The contact between the substrate and the enzyme causes a change in the shape of the active site.B. The shape of the substrate and the shape of the active site are complementary to each other.C. The substrate fits into the active site and forms bonds with the amino acids at the active site.D. All of the above. EXPLANATIONThe enzyme substrate complex is a temporary molecule formed when an enzyme comes into perfect contact with its substrate.The substrate causes a conformational change, or shape change, when the substrate enters the active site. The active site is the area of the enzyme capable of forming weak bonds with the substrate. QUESTION: How are flat worms not similar to round worms?A. They are both acoelmates.B. They are both triploblastic.C. They both show bilateral symmetry.D. They are both worms. EXPLANATIONFlatworms belong to the phylum Platyhelminthes. They do not have a coelom, respiratory system or a circulatory system.Tapeworms flukes are examples of flatworms. Roundworms are part of the phylum Nematoda. They are bilaterally symmetrical invertebrates.They have a psuedocoelom. Ascaris lumbricodes is the most common human parasite. QUESTION: Which type of sensory structures carrying the touch sensations are present in papillae extending into ridges of the fingertips?A. Hair end organsB. Pacinian corpuscles.C. Meissners CorpusclesD. All of these EXPLANATIONMeissners corpuscles (or tactile corpuscles) are a type of mechanoreceptor. They are touch receptors. They are a type of nerve endings in the skin that are responsible for sensitivity to light touch QUESTION: The animals which belong to division Radiata is/are? A. TriploblasticB. DiploblasticC. RadioblastD. All of these EXPLANATIONThe Radiata is a superphylum that includes both the echinoderms and the ctenophores. The radiata, in this sense, are diploblastic, meaning they have two primary germ layers: endoderm and ectoderm. QUESTION: Enzymes are globular proteins because:A. They have a primary structureB. They have a secondary structure.C. They have a tertiary structure.D. All of the above. EXPLANATIONThe tertiary structure of a protein includes additional three-dimensional shaping and often dominates the structure of globular proteins. The primary structure is simply the sequence of amino acids forming the peptide chain. QUESTION: The neurons responsible for converting various external stimuli that come from the environment into corresponding internal stimuli is called:A. Motor nerveB. Sensory nerveC. Both A and BD. Mixed nerve EXPLANATIONSensory nerves contain axons of sensory neurons. Sensory neurons detect external stimuli and generate electrical impulses that travel along the sensory nerve to the CNS. QUESTION: Carbon dioxide is an Example of?A. Ionic SolidB. Metallic SolidC. Molecular SolidD. Covalent Solid EXPLANATIONA molecular solid is composed of molecules held together by van der Waals forces. Solid CO2 is an example of molecular solid as it has relatively Van Der Waals London Dispersion Forces. QUESTION: Which one of the following is an electrophile?A. Br-B. CH4C. NH3D. H20 EXPLANATIONBr- is a nucleophile, along with H2O and NH3. CH4 is neither, but the more suitable choice for the answer. QUESTION: Glycerol can also be termed as?A. 1 - butanolB. 1, 2, 3 - propanetriolC. 2 - methyl - propanolD. Isobutyl alcohol EXPLANATIONGlycerol contains three carbons, giving it the βpropaneβ part to its name. It has an OH group attached to each carbon which account for β1,2,3- triolβ QUESTION: Isopentane is an example of ______ ?A. Aromatic compoundsB. Branched chain compoundC. Alicyclic compoundsD. None of these EXPLANATIONIt is a branched-chain compound as 4 carbons are connected together in a chain and there is a CH3 branch on the 2nd carbon atom. QUESTION: The unit used to express the relative atomic mass is calledA. Gram unitB. Avogadros numberC. Atomic massD. Atomic mass unit EXPLANATIONOne atomic mass unit (1u) is a mass unit equal to exactly one-twelfth (1/12th) the mass of one atom of carbon-12 isotope, which is the scale used to compare atomic masses. QUESTION: The specific site at which substrate is attached on the enzyme and converted into product is called as ______: A. Reaction siteB. Active siteC. Binding siteD. None of these EXPLANATIONThe active site is the region of an enzyme where substrate molecules bind and undergo a chemical reaction. QUESTION: Metallic character depends on ________ ?A. Electron AffinityB. Ionization energyC. ElectronegativityD. All of these EXPLANATIONMetallic character depends on all of the options. Metallic character is basically defined as the ability of a metal to share/donate electrons. This ability is directly affected by all the given options. QUESTION: Which of the following method is used to prepare acetic acid?A. DistillationB. FermentationC. DehydrationD. Ozonolysis EXPLANATIONProduction of acetic acid can be carried out by aerobic and anaerobic fermentation. The fermentation is usually initiated by yeasts which break down glucose into ethyl alcohol with the liberation of carbon dioxide gas. Following on from the yeasts, bacteria (acetobacter aceti) oxidize the alcohol to acetic acid and water. Usually, ozonolysis followed by hydrolysis of alkynes also yields in the formation of carboxylic acids but in the case of ethyne, instead of acetic acid, glyoxal is formed. QUESTION: H bonding is not present in which of the following _______ ?A. DNAB. ProteinsC. CarbohydratesD. Lipids EXPLANATIONNo hydrogen atom is connected to an oxygen, nitrogen or fluorine atom in lipids. QUESTION: What is the nature of Carbon present in Aldehyde is?A. NucleophilicB. ElectrophilicC. NeutralD. All of these EXPLANATIONThe polarity of the carbon-oxygen bond causes there to be a partial positive charge on the carbon atom and a partial negative charge on the oxygen atom. This electron-deficient carbon atom acts as an electrophile. QUESTION: Salt Bridge is used for the purpose of:A. Producing ElectronsB. Circuit CompletionC. Increasing speed of electronsD. All of these EXPLANATIONYou need a salt bridge to complete the circuit as it contains mobile ions that act as charge carriers. It allows current to flow while allowing different electrolytes to be in contact with the anode and cathode. QUESTION: According to Bohr, the orbits in which electrons revolve around the nucleus are:A. OvalB. EllipticalC. CylindricalD. Circular EXPLANATIONIn atomic physics, the Bohr model depicts an atom as a small, positively charged nucleus surrounded by electrons. These electrons travel in circular orbits around the nucleus QUESTION: Conjugate base of a weak acid is:A. WeakB. StrongC. UnstableD. None of these options are correct EXPLANATIONWeak acids have strong bonds to their H+. Strong acids have weak bonds to their H+. Weak bases have a strong tendency to get H+ and/or donate an electron pair. Strong bases have a weak tendency to get H+ and/or donate an electron pair. Hence conjugate base of weak acid is strong. QUESTION: In balancing, it is very important to identify the substance whose:A. Physical state is changedB. Oxidation number is changedC. Enthalpy is changedD. All of these EXPLANATIONIn balancing an equation, not only should the moles be balanced on both sides but also the charges. QUESTION: Alcohol oxidation gives carboxylic acid through:A. AmideB. Carbonic acidC. KetoneD. Aldehyde EXPLANATIONCarboxylic Acids are only formed through the oxidation of Primary Alcohols. Primary alcohols are first oxidised into aldehydes and then, into carboxylic acids. QUESTION: The electron affinity of fluorine is less than chlorine as we move down the group, this deviation in behavior is due to its:A. Small sizeB. Seven electronC. Thick electronic cloudD. All of these EXPLANATIONFluorine, which is higher up the group than chlorine, has a lower electron affinity. This is because the electrons in the outermost shell of a fluorine atom are closer together. The electron gained also feels a great amount of repulsion from the electrons originally in the outermost shell. Energy is required to keep the gained electron in the shell, causing fluorine to have a smaller electron affinity than chlorine. QUESTION: The general name of ore CaS04.H20 is:A. GypsumB. DolomiteC. CalciteD. Plaster of Paris EXPLANATIONGypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO4Β·2H2O. QUESTION: The correct electronic configuration of Cr is:A. [Ar] 4s23d4B. [Ar] 4s23d5C. [Ar] 4s13d4D. [Ar] 4s13d5 EXPLANATIONWhen 3d subshell has 5 electrons, it becomes more stable than if it had 4 electrons. Hence, it is favoured. QUESTION: Half Life Ξ± =1/a(n-1) where n is:A. Number of reactant moleculeB. Number of moles of reactantC. Number of moles of productD. Order of Reactions EXPLANATIONIn the equation given, n represents the order of reactions. QUESTION: Acetaldehyde in the presence of Con.H2S04 undergoes ______ ?A. DehydrationB. PolymerizationC. CondensationD. Oxidation reaction EXPLANATIONAcetaldehyde is polymerised to paraldehyde in the presence of Concentrated H2SO4. QUESTION: If two substituents are present at 1,4 positions then the isomer is called as _____ ?A. OrthoB. MetaC. ParaD. None of these EXPLANATIONDisubstituted benzene rings can be named based on the relative positions of the substituents: the prefix para is used iif they are found on opposite sides of the ring (1,4). QUESTION: Which of the following properties belong to acetic acid?A. Colourless liquid, odourless, sour tasteB. Bright colour bitter tasteC. Colourless solid, sour taste, pungent smellD. All are incorrect EXPLANATIONAcetic acid is a colourless liquid, with a sour taste and a pungent odour. QUESTION: The half-life of Uranium is:A. 700 Million yearsB. 706 Million yearsC. 89 daysD. 710 Million years EXPLANATIONUranium-235 has a half-life of 710 million years. QUESTION: The ionization energy of group ______ shows abnormal trend:A. 3A & 4AB. 5A & 6AC. 6A & 4AD. 3A & 6A EXPLANATIONOxygen (6a) & Boron (3a) show decrease in ionisation energy. This is because electrons is removed from p subshell instead of s, in boron and is more shielded. So, it is easier to remove. In oxygen, there is pairing of electrons so repulsion occurs and less energy is needed to remove electron. QUESTION: Which of the following is a strong acid?A. EthaneB. Ethyl ChlorideC. EthanolD. Phenol EXPLANATIONPhenols are much more acidic than alcohols because the negative charge in the phenoxide ion is not localized on the oxygen atom, as it is in an alkoxide ion, but is delocalized-it is shared by a number of carbon atoms in the benzene ring. QUESTION: Wholar prepared urea in laboratory for the first time in _____ ?A. 1900B. 1829C. 1850D. 1828 EXPLANATIONIn 1828, Wohler synthesized urea by slowly evaporating a water solution of ammonium cyanate, which he had prepared by adding silver cyanate to ammonium chloride. QUESTION: Heat supplied at constant pressure equals to:A. Activation EnergyB. Internal energy changeC. EntropyD. Enthalpy EXPLANATIONAt constant pressure, the heat of reaction is equal to the enthalpy change of the system. QUESTION: Due to less polarizability of Fluorine, it boils at _______ βA. -188.1B. 188.1C. 184.4D. 184.4 EXPLANATIONFluorine, the most reactive chemical element and the lightest member of the halogen elements and has a boiling point, β188 Β°C (β306 Β°F). QUESTION: In SN2 reactions, the hybridization of carbon in moving from substart to transition state changes from:A. Sp2 to sp3B. Sp to sp2C. Sp3 to sp2D. Sp to sp3 EXPLANATIONNormally, a carbon atom is sp3 hybridized. In the transition state of the SN2 mechanism, the carbon atom is sp2 hybridized due to its planar structure. At this point, carbon almost acquires pentavalency with three full bonds and two partial bonds, and a planar complex is formed, which is sp2 hybridized. QUESTION: Which forces are very significant in non-polar molecules like Cl2, H2 and noble gases?A. Dipole-dipoleB. Induced dipoleC. LondonD. Spontaneous induced dipole EXPLANATIONNoble gases have very little intermolecular forces acting between them since they are monoatomic and unpolarised. Thus, only London dispersion forces act and these directly depend on the number of electrons in a compound. QUESTION: Which of the following is typical transition element?A. ZnB. CdC. CuD. Hg EXPLANATIONA typical transition element cation must have a partially filled 3d subshell. This is true for Cu as Cu2+ has 3d9 configuration. QUESTION: Strong acid can be involved in a spontaneous reaction which is termed as:A. Addition ReactionB. Substitution ReactionC. Neutralization ReactionD. Reversible Reaction EXPLANATIONIn a neutralisation reaction, entropy increases, hence reaction is spontaneous. QUESTION: In electrochemical series, reduction potential relates to only:A. Real ConditionsB. Standard ConditionsC. Positive ValuesD. Negative Values EXPLANATIONThe standard electrode potentials are customarily determined at solute concentrations of 1 Mole per dm3 concentration, gas pressures of 1 atmosphere, and a standard temperature which is usually 25Β°C. QUESTION: Left-handed helix in proteins secondary structure is called as ______ :A. Alpha helixB. Beta helixC. SpiralD. Concentrate EXPLANATIONExplanation for this question will be added shortly. QUESTION: The maximum number of electrons that can be accommodated in M Shell of an atom are:A. 8B. 32C. 18D. 25 EXPLANATIONThe maximum number of electron that can accommodate in a shell is given by the formula 2n2 M shell n=3, hence M can accommodate 18 electron. QUESTION: The electrolysis of acetate solution produces ethane according to reaction: 2CH3COO- --> C2H6(g) + 2CO2(g) + 2e- The current efficiency of the process is 80%. What volume of gases would be produced at 27oC and 740 torr, if the current of 0.5 amp is passed through the solution of 96.45 min?A. 6.0 LB. 0.60 LC. 1.365 LD. 0.91 L EXPLANATIONCorrect option is D. QUESTION: PV/nRT for an ideal gas is called:A. Expansion factorB. Depression factorC. Compressibility factorD. Diffusion factor EXPLANATIONCompressibility Factor is also often defined as βthe ratio of molar volume of gas to that of an ideal gas.β It is expressed as Z = pV / RT. QUESTION: I- is an example of ________ ?A. ElectrophileB. NucleophileC. Leaving groupD. Both nucleophile and leaving group EXPLANATIONIt is a nucleophile as it is attracted towards positive centre due to a free pair of electrons ready to bind. It is a leaving group as it can leave with a pair of electrons in heterolytic fission. QUESTION: Temperature and volume in an experiment are part of?A. SurroundingsB. SystemC. State of a systemD. All of these EXPLANATIONA thermodynamic state of a system is defined by specifying values of a set of measurable properties sufficient to determine all other properties. For fluid systems, typical properties are pressure, volume and temperature. QUESTION: Aspartame, an artificial sweetener contains 9.52 weight per nitrogen. There are two nitrogen atoms per molecule. The molecular weight of aspartame is:A. 147B. 294C. 588D. 266 EXPLANATIONCorrect option is B. QUESTION: Which of the following has an amide functional group?A. R - COOHB. R - CHOC. R - CO - RD. R - COO - RE. R- CO - NH2 EXPLANATIONAmide functional group is given by βCOβNH2 . So (E) is correct option. QUESTION: Evaporation is a _____ process.A. ExothermicB. SpontaneousC. Non-SpontaneousD. None of these EXPLANATIONIt is a spontaneous process as entropy increases with the change in state. QUESTION: If uncertainty in momentum of electron is zero, the uncertainty in its position would be _______ .A. Less than zeroB. More than zeroC. OneD. Infinite EXPLANATIONPosition and velocity of electron cannot both be measured accurately at the same time. If you are able to measure one, you cannot measure the other. Hence, if momentum has zero uncertainty, its position will have maximum uncertainty (infinite). QUESTION: From which of the following ketone can be prepared?A. PropyneB. Secondary alcoholC. Ca AcetateD. All of these EXPLANATIONThe addition of water to an alkyne (propyne) leads to the formation of an unstable vinyl alcohol. These unstable materials then form ketones. Secondary alcohol is oxidised to form ketone. When calcium acetate is heated to 350Β°, it forms acetone (ketone). QUESTION: On which of the following factors Hydration Energy depend?A. Charge to size ratioB. Polarizability of anionsC. Polarization power of CationsD. All of these EXPLANATIONThe magnitude of hydration enthalpy depends on the charge density of the ions. The charge density is more for smaller ions and hence the smaller ions have higher values of hydration enthalpy. The higher the charge density the higher will be the force of attraction between the ion and the water polar end. QUESTION: The crude petroleum is separated in fraction by:A. FiltrationB. Fractional distillationC. Steam distillationD. Fractional sublimation EXPLANATIONFractional distillation is used to separate crude oil into simpler, more useful fractions. A fraction of crude oil is a group of hydrocarbon molecules of similar size with similar boiling points. Their similar boiling points mean that they can be separated by fractional distillation. QUESTION: Distillation of calcium acetate and calcium formate produces?A. FormaldehydeB. AcetaldehydeC. AcetoneD. None of these EXPLANATIONA mixture of calcium formate and calcium acetate on dry distillation gives Acetaldehyde. QUESTION: After the hydrolysis of ester the change in concentration of acid at different intervals is calculated by:A. Titration with KMnO4B. Titration with Standard AlkaliC. DistillationD. Evaporation of mixture EXPLANATIONExplanation for this question will be added shortly. QUESTION: Most of the enzyme reactions are ______ .A. ReversibleB. IrreversibleC. CondensationD. Oxidation EXPLANATIONEnzymes are able to show reversible reactions. This means that they may be able to form product by combining two substrates. However, the enzyme will also be able to form the two original substrates by breaking the product down. QUESTION: Caustic Soda is made by electrolysis of concentrated solution of NaCl in:A. Nelsons CellB. Hg - CellC. Castner Kellner CellD. All of these EXPLANATIONExplanation for this question will be added shortly. QUESTION: Which of the following has six isotopes?A. ManganeseB. TinC. CalciumD. Carbon EXPLANATIONCalcium has six stable isotopes: 40 42, 43, 44, 46, 48 Manganese has four isotopes: 52, 53, 54, 55 Tin has ten isotopes: 112, 114, 115, 116, 117, 118, 119, 120, 122, 124 Carbon has three isotopes: QUESTION: Which statement is true for K2(Cu(CN)4) ?A. Potassium tetra cyano cuprateB. Coordination number is 2C. The ligand is positively chargedD. Central atom is present in the anionic sphere EXPLANATIONThis is an anionic complex, therefore the coordination sphere is anionic. QUESTION: An orbital can accommodate at the most ______ electrons.A. 2B. 14C. 1D. 6 EXPLANATIONAn orbital has a maximum capacity of 2 electrons which does not change. QUESTION: Which of the following is succinic acid?A. Ethanoic acidB. Hexanedioic acidC. Butanedioic acidD. Propanoic acid EXPLANATIONSuccinic Acid is also known as butanedioic acid. QUESTION: Ethyne has which hybridization?A. Sp3B. Sp2C. SpD. Sp2d EXPLANATIONEthyne molecule is sp hybridized since it has one sigma and two carbon-carbon pi bonds. QUESTION: Change in Pressure will only affect the substances which are in:A. Liquid stateB. Solid StateC. Plasma stateD. Gaseous State EXPLANATIONChanging the pressure of a gas is the same as changing its concentration. As a gas can be compressed, it will be more concentrated at a particular region if pressure is increase. However, this is not true for states other than gases. QUESTION: SI Unit of current is:A. AmpereB. VoltC. JoulesD. Watt EXPLANATIONThis is a standard answer. SI unit of Current is Ampere. The SI unit of Energy is Joules, The SI unit of Power is Watt The SI unit of electric potential difference is Volts QUESTION: When a force is parallel to the direction of motion of body, the work done is:A. ZeroB. MinimumC. InfinityD. Maximum EXPLANATIONExplanation The work done is calculated as the scalar product of force vector and displacement vector. When force is parallel to displacement , the value of So, value of So , work done is maximum. QUESTION: Which unit is used in the measurement of Displacement?A. mB. m/sC. 1/sD. N EXPLANATIONThe unit used in the measurement of displacement is meters. QUESTION: Which is not radioactive?A. OzoneB. HydrogenC. SodiumD. All of these EXPLANATIONOzone, Hydrogen and Sodium are all not radioactive because they have stable nuclei. A substance is said to be radioactive if it contains unstable nuclei and is able to naturally release energy in the process of shedding high speed charged particles, in an attempt to reach a stable state. QUESTION: What is the relationship between Power, Current and Resistance?A. P=l2RB. P=l2R/2C. P=IRD. All of them EXPLANATIONP = VI But V= IR Therefore, P=(IR)ΓI P=IΒ² QUESTION: Which of the following changes when taken together, will result in decrease in the pressure of an ideal gas? A. Volume decreased, temperature decreasedB. Volume decreased, temperature increasedC. Volume increased, temperature decreasedD. Volume increased, temperature increased EXPLANATIONPressure of a fixed mass of gas is directly proportional to volume at constant temperature. (Boyles Law). Pressure of a fixed mass of gas is directly proportional to temperature, at constant volume. (Gay-Lussacs Law) QUESTION: In a stationary wave, the distance between adjacent nodes is equal to:A. Ξ»B. 2Ξ»C. Ξ»/2D. Ξ»/4 EXPLANATIONThe distance between successive nodes or antinodes is half of the wavelength. QUESTION: The frequency of vibration of the string is given by the equation given below. (p is the number of segments in the string and l is the length of the string.) The dimensional formula for m will be:A. [M0LT-1]B. [ML0T-1]C. [ML-1T0]D. [M0L0T0] EXPLANATIONCorrect option is C. QUESTION: Magnetic flux is a?A. Scalar quantityB. Vector quantityC. Sometimes scalar sometimes vectorD. None of these EXPLANATIONMagnetic flux is the dot product of the magnetic field and area. As we are using for products, the magnetic flux is a scalar quantity. (When the magnetic field is along the area of the closed surface, the magnetic flux is 0. It happens because the angle between the area vector and the magnetic field vector is 90 degrees). QUESTION: The heat required to raise the temperature of one mole of the substance through 1 K is called ...A. Specific latent heatB. Heat capacityC. Molar specific heatD. Specific heat capacity EXPLANATIONMolar specific heat capacity is the heat energy required to raise the temperature of 1 mole of a substance by. In SI units, molar heat capacity is the heat in joules required to raise 1 mole of a substance by 1 Kelvin. QUESTION: A particle performing uniform circular motion has constant:A. VelocityB. AccelerationC. PositionD. Momentum EXPLANATIONIn uniform circular motion, the magnitude of linear velocity remains constant although its direction changes every instant. A centripetal acceleration is produced as a result, directed towards the centre of the circular path. The centripetal acceleration is constant, and is given by mvΒ²/r. Velocity cannot be constant, as explained above. Position, of course, cannot remain constant. Since velocity is not constant, momentum cannot be constant. QUESTION: The first law of thermodynamics is a special case of -------A. Newtons lawB. Charless lawC. Conservation of energyD. Conservation of entropy EXPLANATIONThe First Law of Thermodynamics states that heat is a form of energy, and thermodynamic processes are therefore subject to the principle of conservation of energy. This means that heat energy cannot be created or destroyed. QUESTION: Acceleration in the simple pendulum is always _______ to displacement.A. Inversely proportionalB. Directly proportionalC. Acting negativeD. Independent EXPLANATIONAs you have to take double derivative of displacement in order to get acceleration, and the motion of pendulum is sinusoidal, thus a negative sign appears, thus aceleration always acts negative to displacement. QUESTION: The nucleus shape is considered to be:A. SquareB. RectangleC. SphereD. Circular EXPLANATIONIf a nucleus becomes stretched in any particular direction, it tends to break into parts because some of its protons and neutrons are too far from each other. Thus, to maintain stability, the nucleus tends to keep all its dimensions as small as possible, and this is accomplished by a spherical shape. QUESTION: If the peak voltage in the output of full-wave rectifier is 10V, then the DC component of output voltage is:A. 10β2B. 20/β2C. 20/ΟD. 20Ο EXPLANATIONV(DC)= 2V/Ο= (2Γ10)/Ο =20/Ο QUESTION: When a standing wave is set up in a pipe which is open from one end, which of the following statements is true?A. Sum of the number of antinodes and the number of nodes is always evenB. Wavelength = length string / number of nodesC. The shape of the string at any instant shows a symmetry about the midpoint of the stringD. Frequency = number of nodes x fundamental frequency EXPLANATIONA standing wave is either a full wave so the sum of nodes and antinodes is even, or a half wave where number of antinodes and nodes are both odd so their sum is still even. QUESTION: The angular momentum of photon is -------A. InfiniteB. ZeroC. NegativeD. Still not found EXPLANATIONA photon has spin components of angular momentum, when you add the components you get both positive and negative, so it cancels out. QUESTION: Three charges +3, +q and Q are placed on a straight line with equal separation. In order to make the net force on q zero, the value of Q will be:A. 3qB. 2qC. 4qD. 5q EXPLANATIONExplanation for this question will be added shortly. QUESTION: The flux is the region where magnetic field:A. Changes directionB. Changes strengthC. Changes polarityD. Does not change EXPLANATIONMagnetic flux is a static region around a magnet in which the magnetic force exists. Magnetic flux is defined as the number of magnetic field lines passing through a given surface area. QUESTION: In mass-spring system, which of the following does not depend on the initial displacement of the spring?A. Maximum kinetic energy of the massB. Average speed of the massC. Total energy of the massD. Angular frequency of the oscillation EXPLANATIONThe angular frequency refers to the angular displacement per unit time and is calculated from the frequency with the equation Ο=2Οf. The frequency of the spring-mass system is aconstant and depends on mass of the load and the spring constant and not the initial displacement. Therefore, angular frequency does not depend on initial displacement. QUESTION: Current that fluctuates periodically with time is ------A. DC currentB. BC currentC. AC current D. Magnetic current EXPLANATIONAlternating current is an electric current that periodically reverses direction and changes its magnitude continuously with time in contrast to direct current which flows only in one direction. QUESTION: A circuit that adds positive or negative D.C. voltage to an input sine wave is called:A. ClamperB. ClipperC. Diode clampD. Limiter EXPLANATIONA clamper is an electronic circuit that changes the DC level of a signal to the desired level without changing the shape of the applied signal. In other words, the clamper circuit moves the whole signal up or down to set either the positive peak or negative peak of the signal at the desired level. QUESTION: Why are x-rays used in crystallography?A. To prevent interferenceB. To prevent diffractionC. To perform interferenceD. To perform diffraction EXPLANATIONThe X-rays get diffracted by a crystal because the wavelength of X-rays is similar to the inter-atomic spacing in the crystals. QUESTION: Which of the following can have negative temperature coefficient?A. Compounds of silverB. Liquid metalsC. Metallic alloysD. Electrolytes EXPLANATIONAll metals and alloys of metals show a positive temperature coefficient. Electrolytes can have negative temperature coefficient. QUESTION: In an adiabatic process -----------------A. Temperature remains constantB. Pressure remains constantC. Volume remains constantD. There is no transfer of heat EXPLANATIONIn adiabatic process there is no heat transfer i.e ΞQ = 0 QUESTION: Bones image is shown on x-ray photogarph because x-rays can be --------A. Transmitted through bonesB. Reflected by bonesC. Absorbed by bonesD. Scattered by bones EXPLANATIONDense bone absorbs much of the radiation while soft tissue (muscle, fat, and organs) allow more of the x-rays to pass through them. As a result, bones appear white on the x-ray, soft tissue shows up in shades of gray, and air appears black. QUESTION: The output voltage of a rectifier is:A. SmoothB. PulsatingC. Perfectly directD. Alternating EXPLANATIONA rectifier is used to convert alternating current to pulsating direct current not smooth direct current. Perfectly direct current will have fixed magnitude and fixed direction of current. This is not true for the output of a rectifier. QUESTION: Which isotope has highest momentum when moving with same velocity?A. ProtiumB. DeuteriumC. TritiumD. All of these have same momentum EXPLANATIONTritium has the highest momentum when moving with same velocity. Momentum is mass x velocity, tritium has the highest mass. QUESTION: If two photons interact in same direction what will change?A. MassB. EnergyC. IntensityD. None of these EXPLANATIONExplanation for this question will be added shortly. QUESTION: Why should a resistance be introduced in a circuit in series deliberately?A. To increase currentB. To decrease currentC. To control currentD. Just to give a good look to the circuit EXPLANATIONAdding resistance to a series circuit will decrease the current. I = V/R. High current is dangerous. QUESTION: The value of permittivity of material, other than air or space is:A. Greater than unityB. Less than unityC. Equal to unityD. Zero EXPLANATIONThe value of permittivity of material, other than air or space is greater than unity. Value of permittivity in a vacuum is 1, which is the lowest possible permittivity. QUESTION: When an object moves in a circular path, --------------A. Its displacement is constantB. Its displacement changes due to change in distanceC. Its displacement changes due to change in direction of motionD. Its displacement is always zero EXPLANATIONAt the end of each revolution, the object returns to the initial point. Therefore, the net displacement covered is zero. QUESTION: If north is the positive direction, which situation involves positive velocity and negative acceleration?A. A car speeding up as it moves southwardB. A car moving southward at a constant speedC. A car slowing down as it moves northwardD. A car slowing down as it moves southward EXPLANATIONThe rate of change of velocity with respect to time is known as acceleration. Negative acceleration means a decrease in velocity with respect to time. If a car is moving northward and slowing down, the displacement will be along the north (positive), so the velocity will be positive until it gets stopped. As the car is slowing down, the acceleration will be negative. QUESTION: The clouds are formed when water _____ heat.A. AbsorbsB. ReleasesC. First absorbs than releasesD. First releases than absorbs EXPLANATIONThe process of evaporation followed by condensation result in cloud formation. Heat is absorbed during evaporation and released during condensation. QUESTION: If the velocity of a charged particle and magnetic field are at a fixed angle that is not 90 degrees, then the path will be: EXPLANATIONForce is given by F = qvBsinΞΈ, where F, q, v and B are the force, charge on particle, velocity of particle and magnetic field strength respectively. ΞΈ is the angle between v and B. If ΞΈ = 0 or 180, there is no force on the particle and it continues to move with uniform velocity. If ΞΈ = 90, the force acting on the particle is maximum and perpendicular to the path of the particle. (force acts as a centripetal force and the particle moves along a circular path) When ΞΈ has a value other than 0, 90 or 180, the direction of velocity is either perpendicular or parallel to B. If the component of velocity is parallel to B it will not be affected by the magnetic field. However if the component of velocity is perpendicular to B it will be subject to a force of the magnetic field which would result in uniform circular motion. Hence the particle would have a component along a straight line as well as a circular component. Therefore the path would be in the form of a helix. QUESTION: All of the following are equivalent to watt except: EXPLANATIONPower is measured in watts. P = I x V (power is current times voltage) and it is NOT current divided by voltage. QUESTION: Which of the following phenomenon proves that light waves are transverse waves? EXPLANATIONOnly transverse waves can undergo polarisation. Longitudinal waves cannot undergo polarization. Since light can undergo polarisation, it is a transverse wave. QUESTION: The frequency of the incident photon after Compton effect will: A. remain constantB. increaseC. decrease EXPLANATIONThe energy of photons is directly proportional to their frequency and inversely proportional to their wavelength, so lower-energy photons have lower frequencies and longer wavelengths. Therefore, frequency of incident photon after compton effect will decrease. QUESTION: When the direction of the force and displacement are opposite, work done is:A. NegativeB. PositiveC. ZeroD. None of these EXPLANATIONW=FdcosΞΈ ΞΈ = 180Β° if force and displacement are directed opposite to each other. W=Fd(-1)=-Fd Therefore, the work done is negative. QUESTION: An angular velocity of 60 revolutions per minute is the same as:A. 1/2Ο rad/s EXPLANATIONAngular velocity/frequency is calculated by β΅ = 2πf. f = 60 revolution per minute = 60/60 = 1β΄β΅ = 2π QUESTION: A transformer steps down from 200V to 50V. If it has a secondary winding of 40 turns, then the number of windings in the primary coil are:A. 150B. 160C. 170D. 200 EXPLANATIONNp/Vp = Ns/Vsx/200 = 40/50x = 160 Where, Np is number of turns in primary coilNs is number of turns in secondary coilVp is voltage of primary coilVs is voltage of secondary coil QUESTION: For which angle between area and magnetic field, the flux is maximum?A. 0 degreeB. 90 degreeC. 45 degreeD. 60 degree EXPLANATIONMagnetic flux is measured by Ξ¦ = BAcosΞΈ When ΞΈ is 0Β° flux will be maximum because cos0Β°= 1 So Ξ¦ = BA QUESTION: Mutual inductance has a practical role in performance of:A. AC generatorB. Radio chokeC. DC generatorD. Transformer EXPLANATIONA transformer is a device which uses the phenomenon of mutual induction to change the values of alternating voltages and currents. QUESTION: As a result of interference, energy --------A. Is transmitted and reflectedB. Is lostC. Remains unchanged as a whole but is redistributedD. Is gained EXPLANATIONDuring interference, the pattern contains both maxima and minima. This means that the energy emitted by two coherent sources is redistributed in the fringe pattern. QUESTION: If a wheel of radius r turns through an angle of 30Β°, then the distance through which any point on its rim moves is:A. Ο/3rB. Οr/6C. Ο/30rD. Ο/180r EXPLANATIONIf a wheel moves a full circle, it moves through an angle of 360Β° Circumference of a circle is 2πr Distance moved by a point on its rim is 2πr x 30/360 = πr/6 QUESTION: The phase angle between two points in a medium is 3Ο/4. If the distance between these points is 20 cm, then the wavelength of the wave is?A. 8/15 mB. 15/8 mC. 8/15 cmD. 15/8 cm EXPLANATIONPhase angle = 2π/Ξ» x Ξd Where Ξ» is the wavelength of the wave Ξd is the distance between the two points in metersΞ» = 2π/(3π/4) x 20/100= 8/15 QUESTION: If an AC voltage of rms value of 10 volts is applied as input of a half-wave rectifier, then the voltage value of the DC output will be:A. 10 VB. 10.3 VC. 10.7 VD. 9.3 V EXPLANATIONSince we have the voltage at AC input, which is 10 V, we just need to subtract this value by the diode drop, which is 0.7 V; 10 β 0.7 = 9.3V QUESTION: A wire has a resistance of 5.5 Ξ© at 19β and 21.5 Q at 200β. Find the temperature coefficient of resistivity(Ξ±) of the material.A. 0.016 per degree CelsiusB. 32 per degree CelsiusC. 0.018 per degree CelsiusD. 0.00106 per degree Celsius EXPLANATIONTemperature coefficient Ι = (π 2βπ 1)/π 2(π2βπ1)Ι = 0.016 per degrees celsius QUESTION: _____ are such nuclei of an element that have the same mass number A, but have different charge number Z.A. IsotopesB. IsobarsC. IsomersD. Isotherms EXPLANATIONIsobars are nuclei that have the same mass number (A), but a different atomic number (Z). Isobars should not be confused with isotopes, which share thesame atomic number, and therefore belong to the same chemical element, but have varying mass numbers. Isomers are two or more nuclides that consist of the same no. of protons and the same no. of neutrons but have different energy and manner of radioactive decay, and that exist for a measurable interval of time. QUESTION: Vector is quantity that ------A. Has directionB. Has magnitudeC. Follow rules of vector additionD. Both direction and magnitude EXPLANATIONVector is a quantity that follows the rules of vector addition. (i) A vector can be added only to a vector. (ii) Closure property of addition: The sum of two vectors is also a vector. Hence, vectors are closed under addition. (iii) Vector addition is commutative QUESTION: Half wave voltage multipliers can provide what degree of voltage multiplication?A. Any doublerB. Any triplerC. Any multiplicationD. None of them EXPLANATIONAΒ voltage multiplierΒ is a specializedΒ rectifierΒ circuit producing an output that is theoretically an integer times the AC peak input, for example, 2, 3, or 4 times the AC peak input. Thus, it is possible to get 200 VDC from a 100 Vpeak AC source using a doubler, and 400 VDC from a quadrupler. Any load in a practical circuit will lower these voltages. QUESTION: A particle having the charge of 20 electrons falls through a potential difference of 100 volts. Calculate the energy acquired by it in electron volt (eV).A. 2.0 x 10-2 eVB. 2.0 x 10-3 eVC. 2.0 x 102 eVD. 2.0 x 103 eV EXPLANATIONEnergy = qV= 20e x 100= 2.0 x 103 eV QUESTION: An ideal gas at 15.5Β°C and pressure 1.72Γ105 Pa occupies a volume of 2.81m3. How many moles of gas are present?A. 2.01 molB. 21 molC. 201 molD. 2001 mol EXPLANATIONT = 15.5βP = 1.72 x 105 PaV = 2.81 m3 PV = nRT(1.72 x 105)(2.81) = n(8.31)(15.5 + 273)n = 201 mol QUESTION: Is it possible to separate north pole only from bar magnet?A. YesB. NoC. In some cases it is possibleD. None of these EXPLANATIONNorth and south poles always occur in pairs. Attempts to separate them result in more pairs of poles. If we continue to split the magnet, we will eventually get down to an iron atom with a north pole and a south poleβthese, too, cannot be separated. QUESTION: A particle radioisotope has a half-life of 5 days. In 15 days, the probability of decay in percentage will be:A. 67 %B. 87.5%C. 82.5 %D. 77% EXPLANATIONThe half-life = 5 days 15 days mean 3 half-lives After 15 days the number of atoms present in radioisotope sample = N(1/2)^3 = N(1/8) Where N is the number of atoms in the radioisotope sample at t=0 So, probability of decay = [ (N - N/8)/N ] x 100 = 87.5 % QUESTION: The ratio of mass of electron to neutron is:A. 1B. 1200C. 1300D. None of these EXPLANATIONNeutron has a mass nearly 1,839 times greater than that of the electron. QUESTION: Statements:All film stars are playback singers. All film directors are film stars.Conclusions:I. All film directors are playback singers.II. Some film stars are film directors. Which of the following is true?A. Only conclusion II followsB. Either I or II followsC. Neither I nor II followsD. Both I and II follows EXPLANATIONSince both the premises are universal and affirmative, the conclusion must be universal affirmative and should not contain the middle term. So, I follow. II is the converse of the second premise and so it also holds. QUESTION: Fact l: All drink mixes are beveragesFact 2: All beverages are drinkableFact 3: All beverages are redIf the above three statements are facts then which of the following statement will also be a fact?I. Some drink mixes are redII. All beverages are drink mixes.III. All red drink mixes are drinkableA. I onlyB. II onlyC. III onlyD. None of them is a fact EXPLANATIONDrink mixes may or may not be red, so option I is not a fact. All drink mixes are beverages but beverages can also be other than drink mixes, option II is also not a fact. Because all drink mixes are beverages and all beverages are drinkable, therefore all red drink mixes will be drinkable. Option III is a fact. QUESTION: Statement: The availability of imported fruits has increased in the indigenous market and so the demand for indigenous fruits has been decreased. Course of Action: 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 follow.B. None of them follow.C. Only I follows.D. Only II follows. EXPLANATIONThe 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: Statement:The Management of School M has decided to give free breakfast from next academic year to all the students in its primary section through its canteen even though they will not get any government grant.Courses of Action(I) The school will have to admit many poor students who will seek admission for the next academic year.(II) The canteen facilities and utensils have to be checked and new purchases to be made to equip it properly.(III) Funds will have to be raised to support the sc heme for years to come.A. Only II and III followsB. Only III and I followC. Only I and II followD. Only I follows EXPLANATIONSince the school has introduced the scheme without receiving any grant, it needs to pool up the funds and make adequate arrangements to keep the scheme going. So, only II and III follow. QUESTION: Statement:I. Majority of the citizens in the locality belongs to higher income group.II. The sales in the local supermarket are comparatively much higher than in other localities.A. Statement I is the cause and statement II is its effect.B. Statement II is the cause and statement I is its effectC. Both the statements I and II are independent causesD. Both the statements I and II are effects of independent causes EXPLANATIONthe reason why sales are comparatively high in a particular locality is because the residents of the locality are capable of paying high prices. QUESTION: What should come next to infirmary?A. SurgeryB. DiseaseC. PatientD. Receptionist EXPLANATIONAn 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: What should come next: save, secure, protect, -----A. GaurdB. LockC. ConserveD. Humble EXPLANATIONsave is a synonym of secure so to follow the pattern the answer needs to be a synonym of protect, which is guard. QUESTION: Directions:In each of the following questions a statement is given, followed by two conclusions.Statement: Please do not wait for me, I may be late, start taking lunch as soon as the guests arrive. - A message from a Director of a Company to his office managers.Assumptions:I. Keeping guests waiting is not desirable. II. Lunch may not be ready in time.A. Only assumption I is implicit EXPLANATION the Director instructs his managers not to keep the guests waiting because of him and to proceed with lunch soon after their arrival. This implies that lunch would be ready in time. So, only I is implicit. QUESTION: Statement: I. Large number of Primary Schools in the rural areas is run by only one teacher.II. There has been a huge dropout from the primary schools in rural areas.A. Statement I is the cause then 2 is its effect EXPLANATIONOne teacher running a lot of schools leads to mismanagement and it lowers the educational standard which causes students to drop out from school in rural areas. QUESTION: Complete the series A2.5, B5, C7.5, _____ ?A. D9B. D10C. D9.5D. D45 EXPLANATION2.5 is added to each number. 2.5+2.5=5 and 5+2.5=7.5 hence 7.5+2.5=10 and D is 10. Quote Link to comment Share on other sites More sharing options...
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