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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:

Aslam and his friends were making too much noise. Their father got really ___ at them.
 

A.

Afraid  

B.

Angry

C.

Kind

D.

Strong

EXPLANATION

Since noise is unwanted, the father would get angry by it, instead of kind, strong or afraid.


QUESTION:

___ anyone ____ a pencil I could borrow? 

A.

Do ... have 

B.

Does.. have

C.

 Do .. has 

D.

Does.. has

EXPLANATION

The first blank is “does” since does is used when referring to something singular and do is used for something plural, and the person is asking if any one (single) person could lend him a pencil. The second blank is “have” since we use have with first and second person; “has” cant be used with “I”. 


QUESTION:

Choose the correct sentence.

A.

Dr Hussain works at city hospital in gulberg.

B.

Dr Hussain works at City Hospital in Gulberg?

C.

Dr Hussain works at City Hospital in Gulberg. 

D.

Dr Hussain works at city hospital in Gulberg. 

EXPLANATION

Since this is a statement, the suitable punctuation is a fullstop at the end. Proper nouns are required to have their first letter capitalised.


QUESTION:

I found this bangle while digging in the backyard. I dont know who it belonged to. 

EXPLANATION

As the person is speaking in present tense, all verbs should be in present tense, hence it should be I dont know whom it belongs to.


QUESTION:

What is your name?

A.

Declarative

B.

Imperative 

C.

Interrogative 

D.

Exclamatory 

EXPLANATION

A question is being asked therefore it is an interrogative remark, and not declarative, exclamatory, or imperative.


QUESTION:

Children usually ____ a noise. 

A.

Made

B.

Makes

C.

Are making

D.

Make

EXPLANATION

A noise imply use of a singular object and makes cant be used with singular.


QUESTION:

Most of the milk ____ gone bad. Six gallons of milk ____ still in the refrigerator. 

A.

has ... are 

B.

 have .. is 

C.

has .. is  

D.

have ... are  

EXPLANATION

Have is used with the pronouns I, you, we, and they, whereas has is used with he, she, and it, therefore while referring to the milk (it), has is suitable. Since we are talking about more than one gallon of milk, are will be used.


QUESTION:

Choose the correct spelling of the word 

A.

Doen 

B.

Dun 

C.

Don 

D.

Done

EXPLANATION

Done is the past tense of do. If spelt dun, it would be the past form of du. 


QUESTION:

 Choose the correct sentence . 

A.

After class, but before lunch, I went jogging.

B.

After class, but before lunch I went jogging. 

C.

After class but before lunch, I went jogging. 

D.

After class, but before lunch, I went jogging! 

EXPLANATION

An exclamation mark will not be used as it is not an exciting statement. Commas are necessary to provide separation between different phrases of complex sentences, in order to avoid misreading of the intended meaning.


QUESTION:

In most countries, children start primary school _____ the age of six.  

A.

in

B.

on 

C.

at

D.

to

EXPLANATION

At is a preposition used to refer to any time or place (the school in this case).


QUESTION:

Which brand do you ____ Honda or Toyota? 

A.

Rather  

B.

Eat

C.

Prefer 

D.

Wear 

EXPLANATION

This question is comparing two things so to opt for which one we like better than the other, we would use prefer.


QUESTION:

Rectify 

A.

Correct

B.

Preserve 

C.

Repeat

D.

Justify 

EXPLANATION

Rectify means to put right, correct, or amend something.


QUESTION:

The baby cried most of ____ night. 

A.

a

B.

an

C.

the

D.

no article 

EXPLANATION

The must be used while referring to specific of particular nouns like the night.


QUESTION:

I would love to be able to swim if I am not afraid of water. 

A.

l would love  

EXPLANATION

The sentence is in past tense (use of the word “would”) and so all verbs must follow the same tense, though am is present tense.


QUESTION:

Which verb is NOT in the future tense?  

A.

He will go

B.

He will eat 

C.

He will work 

D.

He eats 

EXPLANATION

Eats is the present form of the verb “eat” and does not indicate that this action will take place in the future.


QUESTION:

Find the error.

A.

It has not rained since April.  

B.

The jurors walked solemnly into the room.  

C.

Had we known, we would not have come. 

D.

No mistakes
 

EXPLANATION

All sentences have correct punctuation and follow the same tense through out.


QUESTION:

Not only the students but also their instructor ____ been called to the principals office. 

A.

Has

B.

Have

C.

Were

D.

Was

EXPLANATION

Has is used for singular nouns (instructor) and is the perfect aspect to be used before “been”.


QUESTION:

Choose the correct sentence. 

EXPLANATION

This is the correct answer since all the punctuation is accurate, for eg: capitalizing first letter of the first word in dialogue, capitalizing proper nouns, and the abbreviations associated.


QUESTION:

Who is ____ lady in ____ picture?

A.

the... an

B.

a... the

C.

the... a

D.

the... the

EXPLANATION

The is used before singular nouns (lady, picture) and to highlight the specificity of a certain object.


QUESTION:

Choose the correct spelling of the word

A.

Aniversary

B.

Anniversery

C.

Anniversary

D.

Aniversry

EXPLANATION

Anniversary is the date on which a memorable event took place. 


QUESTION:

What is the strengthening material of the prokaryotic cell wall? 

A.

Cellulose 

B.

Chitin 

C.

Silica waxes and lignin 

D.

Peptidoglycan or murein 

EXPLANATION

Prokaryotic cell wall; It lacks cellulose. Its strengthening material is peptidoglycan or murein. 


QUESTION:

Which one is not the characteristic of Kingdom Animalia ?

A.

All animals are ingestive heterotrophs 

B.

All animals are eukaryotes 

C.

It is largest kingdom 

D.

All animals develop from the dissimilar gametes 

EXPLANATION

Kingdom Animalia is also known as Metazoa. All animals are members of the Kingdom Animalia. Kingdom Animalia does not contain prokaryotes (Kingdom Monera, like bacteria, algae) or protists (Kingdom Protista, like unicellular eukaryotic organisms). 


QUESTION:

What is an example of sperms of liverworts, mosses, ferns which move towards archegonia, in response to nucleic acid released by the ovum?

A.

Chemotropic movement 

B.

Chemonastic movement

C.

Haptonastic movement 

D.

Chemotactic movement

EXPLANATION

As nucleic acid is type of chemical signal for sperms so, that is why this chemical is sensed by sperm to reach ovum.


QUESTION:

Adaptation of traits to better fill a niche is known as which of the following? 

A.

Polymorphism

B.

Gene linkage 

C.

Speciation

D.

Replication 

EXPLANATION

Speciation occurs when a group within a species separates from other members of its species and develops its own unique characteristics. 


QUESTION:

Coccobacillus has a shape similar to which of the following? 

A.

Rod

B.

Egg

C.

Ball

D.

 None of these

EXPLANATION

It is a type of bacteria characterized by oval or rod shape. It comes from the words “cocci” and “bacilli.” Cocci are bacteria with a sphere shape while the bacilli are bacteria with a rod shape. If the bacteria have these two shapes, then they are called coccobacilli. 


QUESTION:

The Compound Microscope was first used by;

A.

A.V. Leeuwenhoek

B.

Pasteur

C.

Hans

D.

Janssen

EXPLANATION

A.V.Leeuwenhoek first discovered the microscope.


QUESTION:

 Nicotinamide adenine dinucleotide is an example of: 

A.

Coenzymes

B.

Holoenzymes

C.

None of these

D.

Both of these

EXPLANATION

Nicotinamide adenine dinucleotide (NAD) is one of the most important coenzymes in the cell. Not surprisingly, NAD and the closely related NADP are the two most abundant cofactors in eukaryotic cell.


QUESTION:

The loss of liquid via the hydathodes is called:

A.

  Ascent of sap

B.

Guttation

C.

Plamolysis

D.

Imbition

EXPLANATION

Guttation is the loss of water in the form of liquid through hydathodes or water stomata. It occurs due to positive root pressure and serves to remove excess water from the plant. 


QUESTION:

Herpes simplexes is caused by which virus?

A.

Adenovirus

B.

 Influenza virus

C.

Poxvirus

D.

Herpes virus

EXPLANATION

Infection with herpes simplex virus (HSV), known as herpes, is common globally. HSV type 1 (HSV-1) is typically transmitted by oral-to-oral contact and causes infection in or around the mouth .


QUESTION:

Two species can avoid competition, and better use the environments resources by occupying different?

A.

Adaptations

B.

Polymorphism

C.

Specilaization

D.

Niches

EXPLANATION

Two species can avoid competition, and better use the environments resources by occupying different niches. As long as two species occupy different niches, theres no competition because they use different resources. When niches overlap, theres competition.
 


QUESTION:

Glycolysis takes place in the

A.

Nucleus

B.

Cytosol

C.

Mitochondira

D.

Ribosomes

EXPLANATION

Glycolysis is a metabolic pathway that takes place in the cytosol and creates the energy that cells use for things like respiration.


QUESTION:

Which of the following is a method of asexual reproduction? 

A.

Sporulation

B.

Fission

C.

Apomixis 

D.

All of these options are correct

EXPLANATION

Sporulation: Leads to spore formation asexually.

Fission: Mechanism of asexual reproduction in prokaryotes.

Apomixis: asexual seed formation in higher plants where the ovum gets fertilized by another cell of the embryo sac. Since both cells are of the same parent, the reproduction is asexual regardless of gamete formation taking place.

Hence, the all of these options are correct.


QUESTION:

What does the plueral membrane cover?

A.

Heart

B.

Lungs

C.

Brain

D.

Kidney

EXPLANATION

The pleural membranes cover the lungs and have a pleural fluid in between them to lubricate the lungs and prevent damage due to friction.  


QUESTION:

Out of 31 pairs of spinal nerves, how many are pairs of coccygeal nerves? 

A.

1

B.

12

C.

15

D.

10

EXPLANATION

There are eight pairs of cervical nerves, twelve pairs of thoracic nerves, five pairs of lumbar nerves, five pairs of sacral nerves, and one pair of coccygeal nerves.
 


QUESTION:

What is the major cell infected by the AIDS HIV Virus? 

A.

Lymphocytes

B.

Cancer cells

C.

Stem cells

D.

T lymphocytes

EXPLANATION

The T4 lymphocyte (T-helper cell) has the CD4 receptor on its membrane which allows HIV to enter and infect the cell, making it the primary target of the virus. 


QUESTION:

The hinge joint and ball and socket joints are the types of 

A.

Freely movable joints 

B.

Slightly movable joints 

C.

 Immovable joints 

D.

 None of these 

EXPLANATION

The hinge joint shows movement in one plane while the ball and socket joints allow movement in three planes. Both of them are freely moveable joints since they allow large movements. 


QUESTION:

For attachment, rabies virus binds to a 

A.

Complement receptor


 

B.

Integrin ICAM-1 

C.

Acetylcholine

D.

Epidermal growth factor 

EXPLANATION

Rabies virus seeks entry into cells by attaching to a receptor of acetylcholine in muscles.
 


QUESTION:

Which of these is a characteristic of prokaryotic cells? 

A.

Absence of membrane bound cell organelles 

B.

All of these 

C.

Presence of 70S ribosomes 

EXPLANATION

Prokaryotic cells lack a nucleus, have no membrane-bound organelles, and have 70S ribosomes.
 


QUESTION:

A common polyhedral capsid shape of viruses is a? 

A.

Icosahedron 

B.

Pentagon 

C.

Cube

D.

Pyramid

EXPLANATION

Polyhedral viruses have several faces forming an icosahedral head.
 


QUESTION:

Which of the following is NOT a characteristic feature of tapeworm? 

A.

Each body segment has two sets of male and female reproductive organs. 

B.

The digestive tract develops from endodermal cells in the embryo. 

C.

The body can be cut into two parts, which are mirror images of each other, in one plane only.


 

D.

None of these

EXPLANATION

Tapeworms do not have a digestive system and are obligate parasites, obtaining nutrients directly from their host. 


QUESTION:

HDI is synthesized in;

A.

Liver

B.

Intestine

C.

Liver and Intestine

D.

Adipose tissue

EXPLANATION

High-Density Lipoproteins (HDL) are made in the liver and the intestines. 


QUESTION:

In Anaerobic respiration, how much % of the energy, present within the chemical bond of glucose, is converted into ATP?

A.

2

B.

4.5

C.

5.6

D.

7.7

EXPLANATION

Anaerobic respiration yields a net of 2 ATPs/glucose molecule while aerobic respiration yields 36 ATPs/glucose molecule. Hence anaerobic respiration yields [(2/36) *100]% of the energy available i.e. 5.6% of the energy available. 


QUESTION:

The event happens in menstrual cycle when level of progesterone declines: 

A.

Ovulation 

B.

Corpus luteum formation  

C.

 Beginning of menses 

D.

.Maturation of ovarian follicle 

EXPLANATION

Progesterone is essential to maintaining the lining of the endometrium. When its levels fall at the end of the menstrual cycle, the endometrium lining sheds leading to menstruation/beginning of menses.
 


QUESTION:

 Metacarpophalangeal joints are examples of:  

A.

Hinge joint

B.

 Saddle joint

C.

 Condyloid joint 

D.

 Ball and socket joint

EXPLANATION

Metacarpophalangeal joints are the intersection of the metacarpals and the phalanges in the hand. These joints are condyloid joints. A condyloid joint is a type of synovial joint where the articular surface of one bone has an ovoid convexity sitting within an ellipsoidal cavity of the other bone. It allows movement in two planes (i.e., flexion or extension, abduction or adduction).
 


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 precursor.

EXPLANATION

Urey-Millar experiments proved that organic molecules could have synthetic origins. This was the basis of the abiogenesis theory.
 


QUESTION:

Growth and development of plant cells is the role of? 

A.

 Parenchymatous cells  

B.

Meristematic cell 

C.

Chlorenchymatous cells 

D.

Sclerenchymatous cells 

EXPLANATION

In higher plants, growth is only restricted to meristematic cells and the cambium. There are three main types of meristems; apical, lateral, and intercalary.  


QUESTION:

The composition of brain stem is 

A.

 Spinal cord, axon, vertebra 

B.

 Cerebrum, cerebellum, pons 

C.

Medula, pons, midbrain 

D.

Thalamus, midbrain, pons 

EXPLANATION

The brain stem is the first part of the brain that forms during development. It comprises the Medulla, pons, and midbrain.
 


QUESTION:

Which of the following is NOT an example of evidence supporting the endosymbiotic theory? 

A.

Mitochondria contain their own DNA, which is a single circular chromosome. 

B.

. Mitochondria and other plastids multiply by binary fission. 

C.

Mitochondria have their own ribosomes, which are 70S

D.

None of these

EXPLANATION

All of the mentioned options show similarity between mitochondria and bacteria, indicating that mitochondria too could have been an independent bacteria initially that got ingested by an endosymbiont cell. This is the basis of and hence supports the endosymbiont theory.
 


QUESTION:

To form a female zygote, the sperm cell must contribute which chromosome? 

A.

X

B.

2X

C.

Y

D.

XY

EXPLANATION

In humans, if the sex chromosomes are XX then the zygote is female and if the sex chromosomes are XY then it results in a male zygote. Females can therefore also only form ovum with an X chromosome. To form a female zygote, the sperm must donate another X chromosome to the ovum to form XX zygote again.
 


QUESTION:

Your neighbor has a flower garden in which there are red flowers and white Howe flowers. These flowers are diploid organisms, and flower color is an autosomal trait. The gene for red flowers (R) is dominant, while the gene for white flowers (r) is recessive. Which of the following could be the genotype of a red flower?  

A.

Rr

B.

Both RR and Rr

C.

Only RR

D.

rr

EXPLANATION

The trait for red flowers (R) is dominant and so is able to express itself in the homozygous (RR) and heterozygous (Rr) - condition both of which will hence yield red flowers.
 


QUESTION:

How many thin filaments are arrayed around each thick filament within a sarcomere?

A.

2

B.

4

C.

6

D.

7

EXPLANATION

Within each sarcomere, 6 thin filaments surround each thick filament while 3 thick filaments surround each thin filament.
 


QUESTION:

The functional parts of forebrain are:

A.

Thalamus and limbic system 

B.

Cerebrum, limbic system and thalamus 

C.

Thalamus and cerebrum 

D.

Cerebrum and limbic system 

EXPLANATION

The forebrain structurally consists of the cerebrum, the limbic system, and the thalamus. The cerebrum acts as the center for thinking, speech, and other activities. Moreover, the limbic system has the function of emotional responses and drives intangible longings (eg: hunger, thirst, lust, etc) while the thalamus serves as a relay and controls consciousness and alertness. So, the answer should be cerebrum, limbic system, and the thamalus. 


QUESTION:

Which of the following is NOT a function of Smooth Endoplasmic Reticulum (SER)? 

A.

 Detoxification of harmful drugs. 

B.

 Synthesis of phospholipids for plasma membrane.

C.

Synthesis of membrane proteins. 

D.

 Synthesis of steroid hormones from cholesterol.

EXPLANATION

Protein synthesis is a function of the rough endoplasmic reticulum and not of the smooth endoplasmic reticulum. 


QUESTION:

Which statement correctly describes, why ions are unable to cross the plasma membrane without channel proteins? 

A.

They are unable to cross the hydrophilic phosphate heads of the lipid bilayer.

B.

 They are unable to cross the hydrophobic tails of the lipid bilayer.

C.

They are unable to cross both the phosphate heads and fatty acid chains of the lipid bilayer.

D.

They are too big to cross the plasma membrane.

EXPLANATION

Ions being are hydrophilic in nature and so are repelled by the hydrophobic interior of the plasma membrane which consists of hydrophobic fatty acid chains. This prevents the ions from freely crossing the membrane without any channel or carrier proteins.


QUESTION:

Identify the characteristic of acoelomates.

A.

Absence of mesoderm

B.

Absence of brain

C.

Coelom that is incompletely lined with a mesoderm

D.

Solid-body without a cavity surrounding internal organs

EXPLANATION

Acoelomates lack a coelom (neither true nor false/pseudocoelom). Hence they lack a cavity surrounding internal organs and have a solid body.


QUESTION:

The nervous system of nematodes consists of which of the following;

A.

Ventral nerve cord

B.

Lateral nerve cord

C.

Dorsal nerve cord

D.

All of these

EXPLANATION

The nervous system of nematodes (roundworm/ascehelmintus) comprises of a ring of nervous tissue beneath the pharynx and four longitudinal nerve cords corresponding to the dorsal region, ventral region, and two lateral regions. 


QUESTION:

 Example of bacteria requiring low concentration of oxygen is?

A.

Spirochete

B.

Seudomonas

C.

E.coli

D.

Campylobacter

EXPLANATION

Campylobacter is a genus of bacteria that are mostly microaerophilic, i.e. they require a very low concentration of oxygen to survive. At higher concentrations, these can not survive.


QUESTION:

Which among the following is a diploblastic organism? 

A.

Hydra

B.

Squid

C.

Earthworm

D.

Crabs

EXPLANATION

Hydra belongs to phylum Cnidaria which is the only diploblastic phylum i.e., its embryo contains only two germ layers; the endoderm and ectoderm connected by a gel-like mesoglea. 


QUESTION:

After fertilisation the zygote increases in size and travels down the Fallopian tube to become embedded in the walls of the womb. This process is called: 

A.

Ovulation

B.

Implantation

C.

Conception

D.

Menstruation

EXPLANATION

Implantation is the process of the zygote increasing in size and embedding itself into the walls of the endometrium.


QUESTION:

Inheritance in man is traced by which of the following?

A.

Mathematical method

B.

Pedigree method

C.

Statistical method

D.

Genetic method

EXPLANATION

A pedigree is a genetic representation of a family tree that diagrams the inheritance of a trait or disease through several generations. The pedigree shows the relationships between family members and indicates which individuals express or silently carry the trait in question .


QUESTION:

The main unit of the thick filament is:

A.

Myofibril

B.

Z-line

C.

Myosin

D.

Actin

EXPLANATION

Myosin is the primary component of the thick filament.


QUESTION:

All of the following are the current preventive methods for HIV infection, except? 

A.

Safe and protected lifestyle

B.

Use of sterile injections and needles

C.

Use of available vaccines

D.

Safe blood transfusion methods

EXPLANATION

There is no vaccine currently available to offer protection against AIDS caused by HIV.


QUESTION:

Choose the region of spinal cord:

A.

Cervical

B.

Lumbar

C.

Thoracic

D.

All of these

EXPLANATION

The spinal cord is divided into 4 regions: cervical, thoracic, lumbar and sacral.


QUESTION:

Which of the following is a function of endoplasmic reticulum?

A.

Transport of molecules

B.

Mechanical support

C.

Conjugated molecules synthesis

D.

All of these

EXPLANATION

The endoplasmic reticulum allows the transport of material in the cell and the synthesis of conjugated molecules (glycoproteins). The membranes of ER act as an ultrastructural skeletal framework in the cell and provide mechanical support.
 


QUESTION:

Centipedes belong to which class of arthropods?

A.

Arachnida

B.

Insecta

C.

Myriapoda

D.

Cephalopoda

EXPLANATION

Centipedes belong to the class Myriapoda of Arthropoda. (myriapoda= many-legs)


QUESTION:

Which of the following statements is a correct distinction between autotrophs and heterotrophs?

A.

Only heterotrophs require chemical compunds from the environment

B.

Cellular respiration is unique to heterotrophs 

C.

Autotrophs, but not heterotrophs can nourish themselves beginning with nutrients that are entirely inorganic.

D.

Only heterotrophs have mitochondria

EXPLANATION

Autotrophs are able to utilize inorganic compounds from their environment (such as carbon dioxide and water) to synthesis complex organic compounds (such as proteins, carbohydrates, and fats) while utilizing sunlight or chemical energy from external sources. Meanwhile, heterotrophs are unable to synthesize organic compounds from inorganic sources and must attain organic compounds from external sources.


QUESTION:

The fluid mosaic model of plasma membrane proposes that membranes are:

A.

Solid

B.

Semisolid

C.

Fluid

D.

Liquid

EXPLANATION

The model suggests that phospholipids are able to diffuse in their layers and the proteins of the membrane appear to give a mosaic appearance. The first part of this model therefore also suggests that the membrane is fluid in nature.


QUESTION:

A gene pool is disturbed by which of the following?

A.

Emigration

B.

Immigration

C.

both A and B

D.

Pan immigration

EXPLANATION

Both emigration (which causes efflux/leaving of genes) and immigration (influx of members and genes) disturb the gene pool of a population.


QUESTION:

Which cells secrete pepsinogen?

A.

Mucous

B.

Parietal

C.

Oxyntic

D.

Zymogen

EXPLANATION

Zymogenic cells in the stomach walls secrete pepsinogen which is then activated to produce pepsin enzyme in the presence of hydrochloric acid.


QUESTION:

How does the electron transport system generate ATP ?

A.

Symbiosis

B.

Chemiosmosis

C.

Both of these

D.

None of these

EXPLANATION

Symbiosis is the reference to an interaction between two organisms belonging to different species. Chemiosmosis is the movement of protons down an electrochemical gradient created by a partially permeable membrane via ATP synthase (stalked particles) embedded in the membrane to produce ATP. 


QUESTION:

Which of these processes is the means by which a bacterium can directly uptake and incorporate foreign DNA from the environment into its genome? 

A.

Transduction

B.

Binary fission

C.

Transformation

D.

Conjugationc

EXPLANATION

Transduction: transfer of genetic material to a bacterium via a virus (or phage).

Transformation: Direct uptake of genetic material by a bacterium from its environment.

Binary fission: Mechanism of asexual reproduction in bacteria

Conjugation: Transfer of genetic material between bacteria by means of sex pilli.


QUESTION:

Glottis is lined by? 

A.

Plasma membrane

B.

Epithelial membrane

C.

Meninges

D.

Mucous membrane

EXPLANATION

Glottis is part of the upper respiratory tract and so, is lined by mucous membranes.


QUESTION:

 An insulin molecule is made up of how many polypeptide chains? 

A.

1

B.

3

C.

2

D.

4

EXPLANATION

Insulin is a protein made up of two polypeptide chains referred to as the A chain and the B chain.


QUESTION:

Which product is formed when carbon dioxide combines with hemoglobin?

A.

Carboxyhemoglobin

B.

Protein

C.

Micelles

D.

Cholestrol

EXPLANATION

Carbon dioxide reversibly binds with amino groups of hemoglobin to form carboxyhemoglobin complex.


QUESTION:

According to the lock and key model, the substrate acts as a:

A.

Key

B.

Lock

C.

Both Options A and B are correct

D.

None of these options is correct

EXPLANATION

The lock and key model refers to an analogy used to describe the specific action of an enzyme with a substrate. During this process, the enzyme is acting as the lock and has a section called the active site which is where the reaction will take place, and the substrate, for instance a protein, is the key.


QUESTION:

How many thin filaments are arrayed around each thick filament within a sarcomere?

A.

2

B.

6

C.

8

D.

4

EXPLANATION

Within each sarcomere, 6 thin filaments surround each thick filament while 3 thick filaments surround each thin filament.


QUESTION:

Enzymes that are, an integral part of ribosomes, are involved in the synthesis of which of the following molecules? 

A.

Protein

B.

Lipid

C.

Cholestrol

D.

All of these

EXPLANATION

Ribosomes are responsible for the manufacture of proteins.


QUESTION:

Skin colour in man is controlled by how many pairs of genes?

A.

1

B.

2

C.

3

D.

4

EXPLANATION

Melanin production and hence skin color is controlled by 3 pairs (6 total) genes in man. 


QUESTION:

The embryo of a turtle, mouse, and human show?

A.

Distinct differences

B.

Analogous structure

C.

Vestigial organs

D.

Comparative embryology 

EXPLANATION

Embryos of the turtle, mouse, and humans show similar features i.e., they show comparative embryology.


QUESTION:

Monosynaptic refers to the presence of how many chemical synapse(s)?

A.

1

B.

2

C.

3

D.

4

EXPLANATION

The prefix “mono” indicates the presence of a single synapse. 


QUESTION:

Glycogen is how glucose is stored in the human body. Where is it most abundantly found? 

A.

Liver

B.

Muscles

C.

Both A and B

D.

Kidneys

EXPLANATION

Glucose is converted and stored as glycogen in the liver and muscle cells due to the action of insulin.


QUESTION:

Catalysts that increase the rate of biological chemical reaction are;

A.

Protein

B.

Vitamin

C.

Carbohydrates

D.

None of these

EXPLANATION

Enzymes are biological catalysts that increase the rate of biological reactions.


QUESTION:

The optimal pH in which the enzyme enterokinase functions is? 

A.

1.0

B.

1.5

C.

2

D.

5.5

EXPLANATION

The enzyme enterokinase (converts trypsinogen to trypsin) has an optimum pH of 5.5.


QUESTION:

The disease characterized by the breakdown of alveoli is called:

A.

Asthma

B.

Tuberculosis

C.

Emphysema

D.

A and B

EXPLANATION

Emphysema is a medical condition where the elastin fibers of the alveolar walls are damaged causing a loss in elasticity of the alveoli leading to difficulty in breathing.


QUESTION:

The dorsal root of spinal cord is:

A.

Sensory

B.

Mixed

C.

Motor

D.

All of these

EXPLANATION

The dorsal root of the spinal cord contains the nerve fibers of the sensory neuron and the cell body of the sensory neuron (which is present in the dorsal root ganglion).


QUESTION:

Darwins Theory of evolution by natural selection is based on all of the following postulates except? 

A.

Some individuals are more successful in surviving and reproduction than others

B.

 Individuals within a population are variable

C.

 The survival and reproduction of individuals is not random 

D.

The survival and reproduction of individuals is random

EXPLANATION

Darwin’s theory of natural selection suggests that individuals of a species have variable traits and they compete with each other in a “survival of the fittest” competition. Mating, survival, and reproduction are therefore not random and instead depend on the environmental conditions and the presence of favorable traits in organisms.


QUESTION:

A plant cell wall is mainly composed of which of the following?

A.

Protein

B.

Lipid

C.

Cellulose

D.

None

EXPLANATION

Cellulose is the primary component of the plant cell wall.


QUESTION:

Most multicellular organisms are which of the following? 

A.

Diploid

B.

Single nucleus

C.

Haploid

D.

None of these

EXPLANATION

For most organisms, the dominant multicellular stage in their lifecycle is diploid in nature.


QUESTION:

A mole of a substance contains _____ particles.

A.

6.2x1022

B.

6.22x1022

C.

6.02x1023

D.

6.5x1022

EXPLANATION

Answer: C 

One mole contains an Avogadro’s number of particles i.e. 6.02x1023


QUESTION:

Which alkali metal only combines with nitrogen?

A.

Li

B.

Fr

C.

Cs

D.

K

EXPLANATION

Answer: A

Lithium is the only alkali metal that reacts with nitrogen to form lithium nitride. This is amongst the peculiar properties of lithium.


QUESTION:

When sudden expansion of gases takes place, cooling occurs. This is called ______.

A.

Freezing effect

B.

Joule Thomson effect

C.

Boyles effect

D.

J.Perrin effect

EXPLANATION

Answer: B 

Joule Thomson effect is the phenomenon accompanying a change in temperature due to a rapid change in the volume of a gas (rapid expansion or rapid compression).


QUESTION:

In which phase, SN2 reactions are favored?

A.

Solid

B.

Liquid

C.

Gas

D.

All of these

EXPLANATION

Answer: C

In the gaseous phase, the energy required for the dissociation of bonds to form the cation ion can not be compensated for by solvation or hydration, or, other types of bond formation since particles are farther apart. Hence, the SN1 reaction mechanism is not possible. Therefore, SN2 reactions are favored in the gaseous phase.


QUESTION:

How many resonance structures of benzene are possible?

A.

2

B.

3

C.

6

D.

4

EXPLANATION

Kekule proposed the following two resonating structures for benzen:


QUESTION:

Aldol condensation takes place in the presence ____.

A.

H2SO4

B.

K2Cr2O7

C.

NaOH

D.

H2O/H+

EXPLANATION

An alkaline catalyst is required for the aldol condensation reaction.


QUESTION:

In Ion Electron Method of Balancing, equations are ____.

A.

Written with oxidation numbers of constituents

B.

Split into two half reactions

C.

Only oxidation part is written

D.

Only reducing part is written

EXPLANATION

In the ion-electron method of balancing, equations are split into two half-reactions corresponding to reduction and oxidation. These equations are then multiplied by the smallest whole number to make the number of electrons donated by the oxidizing species and that gained by the reducing species to be the same. Then both the equations are added together to form the final balanced equation.


QUESTION:

Enthalpy change of solution of Na2CO3 is a _____ reaction.

A.

Exothermic

B.

Endothermic

C.

Spontaneous

D.

Non-spontaneous

EXPLANATION

The enthalpy change of solution of sodium carbonate is -24.6kJ.mol-1.  Since enthalpy change is negative, the reaction is exothermic. However, since the entropy increases, the spontaneity of the reaction depends on the temperature of the system. Therefore, it can not be stated for sure whether the reaction is spontaneous or non-spontaneous.


QUESTION:

In aluminum oxide, ions are present in the ratio 2:3, its formula is ____.

A.

AlO

B.

Al2O

C.

Al2O3

D.

Al3O2

EXPLANATION

Al2O3is the only formula that satisfies both; the stated ratio of 2:3 and the valencies of elements involved (Oxygen: -2, Aluminium: +3).


QUESTION:

Phenol is also called as ____.

A.

Carbonic acid

B.

Carbolic acid

C.

Acetic acid

D.

Hydroxy acid

EXPLANATION

Carbonic acid: H2CO3

Acetic acid: CH3COOH (ethanoic acid)

Carbolic acid: C6H5OH (phenol)

Hydroxy acid: a type of acid found in natural foods


QUESTION:

Alkyl iodides cannot be prepared directly by the halogenation of alkanes because _____.

A.

Iodine reacts slowly

B.

Iodine reacts reversibly

C.

HI formed reduces alkyl iodide again starting material

D.

All of these

EXPLANATION

All of the above reasons contribute to the factors which make it impossible to synthesis iodoalkanes by halogenation of alkanes.


QUESTION:

Who introduced the concept of macromolecules?

A.

Runge

B.

Maxwell

C.

Staudinger

D.

None of these

EXPLANATION

Hermann Staudinger coined the term “macromolecules” in the 1920s and earned his Nobel Prize for it.


QUESTION:

If a double bond is present between two carbons then this class of compounds is called as _____.

A.

Alkanes

B.

Alkynes

C.

Carbonyl

D.

Alkenes

EXPLANATION

The functional group of alkenes is the presence of a double bond between two carbon atoms.


QUESTION:

Equilibrium constant has ____.

A.

Units

B.

No units

C.

Both A and B

D.

A negative value

EXPLANATION

An equilibrium constant can either have units or be dimensionless (have no units) depending on the number of moles of reactants and products.


QUESTION:

NaOH is named as caustic soda because _____.

A.

It corrodes the organic tissues

B.

It is used in soda water

C.

It reacts with chlorine gas

D.

It reacts with fats to form soap

EXPLANATION

NaOH is termed caustic soda due to its corrosive effects on organic tissues. (caustic = to burn)


QUESTION:

Acetaldehyde oxidation will lead to formation of _____.

A.

Acetic acid

B.

Butanoic acid

C.

Propanoic acid

D.

Ester

EXPLANATION

Acetylaldehyde oxidizes to give acetic acid.


QUESTION:

At 0°C what is the physical state of water?

A.

Ice

B.

Liquid

C.

Vapour

D.

Both ice and liquid

EXPLANATION

0 C  at 1 atm pressure is the freezing point of pure water where its solid-state and liquid state coesxist in an equilibrium.


QUESTION:

Acyclic hydrocarbons are also called as ____.

A.

Closed chain hydrocarbons

B.

Open chain hydrocarbons

C.

Ring compounds

D.

Alicyclic compounds

EXPLANATION

Acyclic are open-chain hydrocarbons while cyclic compounds are closed-chained compounds.


QUESTION:

How many molecules of H2 are added in acetylene to form ethane?

A.

1

B.

3

C.

4

D.

2

EXPLANATION

One molecule of H2 when added to acetylene forms ethene. The addition of another molecule of H2 results in the formation of ethane. A total of 2 molecules of H2 are hence required.


QUESTION:

Rate of reaction has ____.

A.

No units

B.

Unit of Moles/dm3

C.

Unit as Moles / litre

D.

Unit as Moles/dm3.s-1

EXPLANATION

Rate of reaction = change in product concentration/time taken, hence its units are mol.dm-3s-1


QUESTION:

Nitrogen N2 has _____ number of electrons, protons and neutrons.

A.

7,8,9

B.

7,7,7

C.

14,14,14

D.

14,14,15

EXPLANATION

The most common isotope of Nitrogen has atomic number 7 and mass number 14. Two atoms of nitrogen in N2 should therefore, have 14 electrons, protons, and neutrons.


QUESTION:

Proteins also contain _____ bonding.

A.

Covalent

B.

Ionic

C.

Hydrogen

D.

Metallic

EXPLANATION

Proteins primarily contain covalent bonds which form their primary structure but they also mostly have hydrogen bonding which forms their secondary structures.


QUESTION:

Energy in the formation of a crystal lattice is ____.

A.

Absorbed

B.

Released

C.

Dependent on crystal size

D.

None of these

EXPLANATION

When a crystal lattice is formed, ionic bonds are formed between ions. Since bond formation is exothermic, therefore this energy must be released to the surroundings.


QUESTION:

Enthalpy is the sum of internal energy and _____.

A.

Work done

B.

Entropy

C.

Potential Energy

D.

Kinetic Energy

EXPLANATION

Enthalpy(H) = Internal energy (U) + PΔV (workdone)


QUESTION:

The arrangement of sub shells or orbitals is according to _____.

A.

2(l+l)

B.

l+l

C.

n+l

D.

2(n+l)

EXPLANATION

The n+l rule is used to arrange subshells and orbitals in order of increasing energy where n is the principal quantum number and l is the azimuthal quantum number.


QUESTION:

In non-polar molecules, the strength of London forces depends on the number of ____.

A.

Moles

B.

Molecules

C.

Atoms

D.

All of these

EXPLANATION

The greater the number of atoms in a given molecule, the greater the electron cloud and, hence the greater the strength of London dispersion forces.


QUESTION:

Atomic radii can be determined by measuring the distance b/w centers of _____ atoms.

A.

Opposite

B.

Adjacent

C.

Parallel

D.

Equal

EXPLANATION

Atomic radius is approximately half the distance between centers of two adjacent atoms.


QUESTION:

Which of the following is a typical transition metal?

A.

Sc

B.

Y

C.

Cd

D.

Co

EXPLANATION

Y and Sc are part of group III B while Cd is part of group II B, both of which are atypical transition elements. Cobalt, however, is a typical transition element.


QUESTION:

The reaction in which a molecule is removed from a compound but no addition takes place is called as _____.

A.

Substitution reaction

B.

Elimination reaction

C.

Addition reaction

D.

Replacement reaction

EXPLANATION

In elimination reactions, molecules are removed from compounds without the addition of subsequent molecules.


QUESTION:

Tautomerism involves the transfer of _____.

A.

Electron

B.

Carbon atom

C.

Functional group

D.

H-atom

EXPLANATION

Tautomerism is the transfer of protons (H+) from one part of a molecule to another as seen in zwitterions of amino acids.


QUESTION:

Which of the following catalysts is used for the preparation of acidic anhydrides?

A.

K2Cr2O7

B.

P2O5

C.

H+/H2O

D.

H2SO4

EXPLANATION

Phosphorous pentoxide is used to condense carboxylic acids to acid anhydrides.


QUESTION:

Which of the following compounds show strong H-Bonding with water? 

A.

C2H6

B.

CH3Br

C.

CH3OCH3

D.

C2H5OH

EXPLANATION

Ethanol (C2H5OH) has a highly electronegative element (oxygen) bonded to elements with low electronegativities (carbon and hydrogen) and so, is able to form hydrogen bonds with water.


QUESTION:

Spectrometry is used when reactants and products absorb _____.

A.

Ultraviolet radiations

B.

Visible radiation

C.

Infrared radiation

D.

All of these

EXPLANATION

All of the above-mentioned radiations may be used for spectrometry.


QUESTION:

Which of the following reactions is used to locate the position of double bond in the compound?

A.

Dehydration

B.

Ozonolysis

C.

Markovnikovs addition

D.

Oxidation with KMnO4

EXPLANATION

The types of products obtained for ozonolysis can be used to determine the position of the double bond in compounds.


QUESTION:

Which of the following compounds is present in camphor and menthone?

A.

Aldehyde

B.

 Alcohol

C.

Esters

D.

Ketones

EXPLANATION

Both; camphor and menthone contain ketone groups.


QUESTION:

In a galvanic cell Copper compartment gets net negative charge due to arrival of ___.

A.

Free charge from zinc sulfate solution

B.

Electrons

C.

Protons

D.

Zinc ions

EXPLANATION

In a galvanic cell, copper loses electrons to form copper ions, giving the copper compartments a negative charge. 


QUESTION:

Heat absorbed by a substance at a constant pressure is equal to ____.

A.

ΔG

B.

ΔH

C.

ΔE

D.

ΔH-ΔE

EXPLANATION

Enthalpy change is the heat absorbed by a substance at constant pressure. 

ΔH= ΔU + PΔV= Q - PΔV + PΔV = Q


QUESTION:

The last subshell of alkaline earth metals is ____.

A.

2s

B.

1s

C.

2d

D.

3d

EXPLANATION

Alkaline earth metals have their valence electrons in the s subshell. 1s is hydrogen and helium,which are not alkaline earth metals and so, the answer is A (2s).


QUESTION:

Phenol is a ____ liquid.

A.

Dense

B.

Hard

C.

Deliquescent

D.

Intermittent

EXPLANATION

Phenol reacts with moisture in the air to give its smell.


QUESTION:

When two carboxylic acids are strongly heated in the presence of P2O5, which product is formed?

A.

Acid halides

B.

Dimer

C.

Acid anhydride

D.

None of these

EXPLANATION

Carboxylic acids are condensed in the presence of P2O5 to give acid anhydrides.


QUESTION:

The enzyme which is used in treatment of cancer in children is _____.

A.

Thrombin

B.

 L-asparaginase

C.

Both

D.

None of these

EXPLANATION

L-asparaginase is an enzyme used to fight anti-cancer cells in children. Thrombin is merely a clotting factor.


QUESTION:

At which temperature does water have maximum density?

A.

2°C

B.

4°C

C.

0°C

D.

<0°C

EXPLANATION

Water has the peculiar property of having its maximum density at 4 Celsius due to hydrogen bonding.


QUESTION:

The sum of mole fraction of the gases in a mixture of gases is _____.

A.

Always greater than 1

B.

Always smaller than 1

C.

May be equal or less than 1

D.

Always 1

EXPLANATION

Like all fractions, the sum of all mole fractions of a mixture is 1.


QUESTION:

At equilibrium, if the concentration of a product is increased, the reaction will proceed to ______.

A.

Forward direction

B.

Backward direction

C.

Remains undisturbed

D.

None of these

EXPLANATION

By Le-Chateliers principle, the system must move in the direction to oppose the increase in product concentration i.e., it must consume the product. Therefore, it must move in the backward direction.


QUESTION:

Change in volume of a system depends only upon ____.

A.

Initial conditions

B.

Final Conditions

C.

Initial and final conditions

D.

Path of the reaction

EXPLANATION

Volume is a state function and therefore, change in its value depends on the initial and final conditions and, is independent of the path taken in between.


QUESTION:

According to _____ theory, atoms were the ultimate particles that cannot be divided further.

A.

Bohrs

B.

Rutherfords

C.

Daltons

D.

Cannizzaros

EXPLANATION

Daltons’ theory stated that atoms were the most fundamental and indivisible particles.


QUESTION:

If 9.8 g of sulfuric acid is dissolved in excess quantity of water, it will yield ____ moles of hydrogen ion (H+) and _____ moles of sulphate ions (SO42-). 

A.

0.1, 0.2

B.

0.1, 0.3

C.

0.2, 0.4

D.

0.2, 0.1

EXPLANATION

Mr (H2SO4) = 2(1) + 32 + 4 (16) = 98g.mol-1

n(H2SO4)= 9.8/98= 0.1

n(H+ ) = 2 x0.1 = 0.2

n(SO4) = 0.1 x 1= 0.1


QUESTION:

Lanthanides and actinides resemble in ____.

A.

Ionization state

B.

Oxidation state

C.

Electronic configuration

D.

Formation of complexes

EXPLANATION

Lanthanides and actinides are both transition elements and form complexes.


QUESTION:

Organic compounds are _____..

A.

Ionic

B.

Non ionic

C.

Non covalent

D.

Covalent

EXPLANATION

All organic compounds are primarily covalent in nature.


QUESTION:

What system has all the three axes and three angles of unequal length and none of the angles 90?

A.

Cubic system

B.

Triclinic system

C.

Tetragonal system

D.

Monoclinic system

EXPLANATION

Triclinic crystals have all unequal axes and, no angle equal to 90 degrees.


QUESTION:

If the total energy of an electron in the first shell of an H-atom is –13.6 eV, then its potential energy in the 1st excited state would be:   

EXPLANATION

This is the following solution: 


QUESTION:

If the lowest energy X-rays have λ = 4.0 x 10-8 m , estimating the minimum difference in energy between two Bohr orbit, where an electronic transition would correspond to the emission of an X-ray, at what minimum Z (atomic number) would a transition from the second energy level to the first result in the emission of an X-ray? 

EXPLANATION

This is the following solution: 


QUESTION:

In the disproportion reaction: H3PO2 → PH3 + H3PO3 

The equivalent mass of H3PO2 is (m = molecular mass of H3PO2): 

EXPLANATION

Following is the solution to this question: 


QUESTION:

For the water gas reaction C (s) + H2O (g) <-> CO (g) + H2 (g)

At 1000 K the standard Gibbs free energy change of the reaction is – 8.314 kJ/mol. Therefore at 1000 K the equilibrium constant of the above water gas reaction is: 

A.

1

B.

10

C.

1/e

EXPLANATION

rGº = – 8.314 × 103

∴– ∆rGº = 8.314 × 103 = RT ln Keq

or 8.314 × 103 = 8.314 × 103 ln Keq

or ln Keq = 1 = ln e or Keq = e = 2.718 


QUESTION:

The calorific value of H2(g) at STP is 12.78 KJ/L. Hence, the approximate standard enthalpy of formation of H2O is:  

EXPLANATION

This is the following solution: 


QUESTION:

A certain engine which operates in a Carnot cycle absorbs 3.347 kJ at 400ºC. How much work is done by the engine per cycle?  

(The temperature of the sink is 100ºC). 

EXPLANATION

This is the following solution: 


QUESTION:

For step down transformer, Ns ______ Np

A.

Equal to (=)

B.

Less than (<)

C.

Greater than(>)

D.

Not equal

EXPLANATION

In a step-down voltage, we decrease the voltage from the primary to the secondary voltage. Since voltage and number of turns are directly proportional, the number of turns in the secondary voltage (Ns) Should be lesser than the number of turns in the primary coil (Np).

NOTE: INCORRECT ANSWER IN MARKING SCHEME


QUESTION:

In a series circuit, current remains? 

A.

Same

B.

Different 

C.

Sometimes same, sometimes different

D.

None of them

EXPLANATION

In a series circuit, the current only has one path to flow through and so, the current must be the same at all points so, as to follow the law of conservation of charge (Kirchoff’s first law).


QUESTION:

Identify the de Broglie expression from the following.

A.

λ= hxp

B.

λ=h/p

C.

λ=h+p

D.

λ=h-p

EXPLANATION

The de Broglie relation states that the wavelength of a matter wave is inversely proportional to the momentum of the particle under consideration. The proportionality constant is calculated to be h i.e., the Planck’s constant. Hence, B correctly represents the de Broglie relation.


QUESTION:

Basically, a potentiometer is a device for

A.

Comparing two voltages

B.

Measuring a current

C.

Comparing two currents

D.

Measuring a voltage

EXPLANATION

A potentiometer is a voltage divider device that divides voltage to compare it against different values. So in a potentiometer, voltage is being compared.


QUESTION:

Cosθ = ϕ/

A.

BA

B.

A

C.

B

D.

B2

EXPLANATION

Φ is magnetic flux and is equal to the dot product of the magnetic flux density and the area. Hence,
Φ= B.A = |B||A|cosθ
Cosθ = Φ/BA


QUESTION:

What does the constant N represent in the equation of state for an ideal gas PV=NkT?

A.

Number of molecules of gas

B.

Number of moles of the gas

C.

Number of nucleons

D.

Number of protons

EXPLANATION

The variable N is representative of the total number of particles of an ideal gas under consideration.


QUESTION:

In a stationary wave, the distance between adjacent antinodes is equal to:

A.

λ

B.

C.

λ/2

D.

λ/4

EXPLANATION

The distance between two successive antinodes or two successive nodes in a stationary wave is half the wavelength.


QUESTION:

The presence of a dielectric between two charged particles:

A.

Reduces the electrostatic force

B.

Increases the electrostatic force

C.

Does not change electrostatic force

D.

Doubles the electrostatic force

EXPLANATION

For a dielectric, the relativistic constant Er is greater than 1. Hence, the electrostatic force between the charges must decrease.


QUESTION:

A temperature of 162 C is equivalent to what temperature in kelvins?

A.

-111 K

B.

362 K

C.

435 K

D.

111 K

EXPLANATION

K = C + 273

162 C = (162 + 273) K = 435 K


QUESTION:

Which element has three isotopes?

A.

H

B.

O

C.

Cl

D.

None of these

EXPLANATION

Hydrogen has three isotopes: H-1, H-2 (deutrium) and H-3 (tritium)


QUESTION:

If the nuclear radius of Al27 is 3.6 fm, the approximate nuclear radius of Cu64 in fermi is

A.

1.2 fm

B.

2.4 fm

C.

3.6 fm

D.

4.8 fm

EXPLANATION

Explanation is given below.


QUESTION:

Half wave rectifier uses:

A.

One diode

B.

Two diodes

C.

Three diodes

D.

Four diodes

EXPLANATION

A half-wave rectifier is simply a single p-n junction diode that conducts only half the cycle of the AC.


QUESTION:

Lasers are produced by:

A.

Stimulated emission

B.

Spontaneous emission

C.

Absorption

D.

All of these

EXPLANATION

The emission of LASERs requires all three of the above-mentioned phenomena.


QUESTION:

An electric filament bulb can be worked from:

A.

D.C supply only

B.

A.C supply only

C.

Battery supply only

D.

All of the above

EXPLANATION

A filament bulb does not require a steady DC supply and can work on AC supply too.


QUESTION:

If 110J heat is added to the system and 40J work is done, then the change in internal energy system should be:

A.

70J

B.

150J

C.

190J

D.

180J

EXPLANATION

ΔU = Heat supplied - Work done by the system= 110 - 40 = 70J


QUESTION:

The existence of positron was discovered in the

A.

Thermal radiation

B.

Cosmic radiation

C.

Electromagnetic radiation

D.

Non-electromagnetic radiation

EXPLANATION

The first of the antiparticles to be detected, positrons were discovered by Carl David Anderson in cloud-chamber studies of the composition of cosmic rays (1932).


QUESTION:

An object moves 20 m in 5 sec. What is the gradient of the displacement-time graph?

A.

25

B.

15

C.

4

D.

1/4

EXPLANATION

Gradient = Δy/Δx = Δdisplacement/Δtime = 20/5 = 4


QUESTION:

Equal masses of paraffin and water are mixed in a container of negligible thermal capacity. Initial temperature of water is 800C and that of paraffin is 20 0C. The final temperature of mixture is:

A.

700C

B.

600C

C.

500C

D.

400C

EXPLANATION

THE QUESTION DOES NOT MENTION HEAT CAPACITIES OF PARAFFIN AND WATER AND SO IS INCORRECT.


QUESTION:

What happens to the flux if applied magnetic field is doubled on the same surface?

A.

Becomes half

B.

Beomes twice

C.

Becomes infinite

D.

Becomes 4 times

EXPLANATION

For the same surface area and angle, magnetic flux and magnetic field intensity are directly proportional so if one is doubled, the other also becomes twice.


QUESTION:

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

A.

Pressure = low temperature = low

B.

Pressure = low temperature = high

C.

Pressure = high temperature = low

D.

Pressure = high temperature = high

EXPLANATION

A real gas can be approximated to be an ideal gas at low pressure and high temperature since, for these values, the volume occupied the gas is extremely large so, the intermolecular forces of attraction have a decreasingly negligible effect.


QUESTION:

Centripetal acceleration always acts ________ the center.

A.

Away

B.

Towards

C.

Normally

D.

Tangentially

EXPLANATION

The word “centripetal” also means center-seeking/towards the center. The centripetal acceleration always acts towards the center of the circle.


QUESTION:

The photon is the particle which has:

A.

Infinite rest mass

B.

Rest mass but no charge

C.

No rest mass & no charge

D.

A & C are correct

EXPLANATION

A photon is simply a quantized particle of light and so has no rest mass nor charge.


QUESTION:

Calculate the frequency of photon associated 500 nm wavelength(14)

A.

5 x 1014 Hz

B.

6 x 1014Hz

C.

7 x 10(14) Hz

D.

9 x 10(14) Hz

EXPLANATION

v=f λ

f= v/λ = 3x10^8/500 x 10^-9 = 6x10^(14) Hz


QUESTION:

A body moving along the circumference of a circle completes two revolutions.
If the radius of the circular path is R, the total angular displacement covered is?

A.

πr

B.

2πr

C.

Zero

D.

EXPLANATION

Since two revolutions are completed, the angle subtended by the body in its journey is equal to 2x2ℼ= 4ℼ.


QUESTION:

Which of the following is the unit of mutual inductance?

A.

VsA-2

B.

V3sA2

C.

V2s

D.

VsA-1

EXPLANATION

According to faraday law,
Induced emf = L I /change in time
[L]= [Emf] x [time] /[Current] = Vs.A-1


QUESTION:

What will happen in a time of 7 hours, if a radioactive substance has an average life of 7 hours?

A.

Half of the active nuclei decay

B.

Less half of the active nuclei decay

C.

More than half of the active nuclei decay

D.

All active nuclei decay

EXPLANATION

Average life is the time it takes for almost all nuclei to decay i.e., more than half the number of nuclei decay but not all of them.


QUESTION:

Amperes law is ∫B.dl =

A.

µI2

B.

µ/I 

C.

µI

D.

2

EXPLANATION

Ampere’s law states that the sum of the dot product of the tangential components of magnetic induction (B) and, the respective length of individual elements (dl) of a closed path around a conductor, is equal to the product of the current enclosed (I) and u (magnetic permeability).


QUESTION:

In a standing wave, the distance between a node and consecutive anti-node is:

A.

Equal to one wavelength

B.

Equal to two wavelengths

C.

Equal to half of wavelength

D.

Equal to quarter of wavelength

EXPLANATION

The distance between a node and its consecutive antinode is a quarter of the wavelength.


QUESTION:

Transistors can be used as:

A.

Half wave rectifier

B.

Full wave rectifier

C.

Both

D.

None of these

EXPLANATION

Transistors can not act as rectifiers. They may, however, act as amplifiers.


QUESTION:

At which angle work done is maximum?

A.

45-degree

B.

90 degree

C.

0-degree

D.

180 degree

EXPLANATION

Work done is the dot product of force and displacement. Hence,

Work done = F d cos θ.

Since cos θ is maximum at 0 radians or degrees,the work done is also maximum at 0 degrees.


QUESTION:

Which of the following blocks will release heat fast?

A.

Rough white surface

B.

Polished white surface

C.

Rough black surface

D.

Polished black surface

EXPLANATION

Rough and black surfaces are the perfect emittors and absorbers while shiny/polished and white surfaces are the best reflectors and poor emitters and absorbers.


QUESTION:

For clockwise rotations direction of angular velocity is

A.

Positive

B.

Negative

C.

Zero

D.

Infinite

EXPLANATION

By convention, anticlockwise movement is considered positive angular velocity and clockwise rotation is considered negative angular velocity.


QUESTION:

An adiabatic change is the one in which:

A.

No heat is added to or taken out of a system

B.

No change of temperature takes place

C.

Boyles law is applicable

D.

Pressure and volume remains constant

EXPLANATION

In an adiabatic process, no energy is added to or removed from the system in the form of heat.


QUESTION:

Which radiation is used in greenhouse effect?

A.

UV

B.

IR

C.

X-rays

D.

Gamma-rays

EXPLANATION

The UV light from Sun is converted to IR as it interacts with the Earth’s surface and this IR is then trapped by green house gases such as carbon dioxide and methane which causes a temperature rise leading to the greenhouse effect. Hence IR is primarily responsible for the greenhouse effect.


QUESTION:

What is the SI Unit of Potential difference?

A.

Volts

B.

Coulomb

C.

Meter

D.

Newton

EXPLANATION

Volts is the SI unit of potential difference.


QUESTION:

A capacitor stores charge Q at potential difference ΔV. What happens if the voltage applied to the capacitor by a battery is doubled to 2 ΔV?

A.

The capacitance falls to half its initial value, and the charge remains the same

B.

Th capacitance and the charge both fall to half their initial values

C.

The capacitance and the charge both double

D.

The capacitance remains the same, and the charge doubles

EXPLANATION

Since the capacitor an its nature is not changed, the capacitance must remain constant. In the equation: C = ΔQ/ΔV, if C (capacitance) is a constant, then ΔQ (charge stored) and ΔV (potential differencce) are directly proportional. Hence if ΔV doubles, then charge stored also doubles.


QUESTION:

For angular acceleration, clockwise rotation means torque is

A.

Positive

B.

Negative

C.

Zero

D.

Infinite

EXPLANATION

By convention, anticlockwise movement is given a positive sign and clockwise rotation is given a negative sign.


QUESTION:

Superposition of two waves having same frequency, same amplitude and travelling in the opposite direction is called:

A.

Interference

B.

Diffraction

C.

Beats

D.

Stationary waves

EXPLANATION

Stationary waves are formed when two waves with the same frequency and amplitude, but travelling in opposite directions interfere with each other.


QUESTION:

The minimum charge on an object cannot be less than:

A.

1.6 X 10-19 C

B.

9 X 109 C

C.

9.1 X 10-31 C

D.

1.6 X 10-27 C

EXPLANATION

The smallest unit charge is that of the electron or a proton in magnitude i.e. 1.6x10(-19)


QUESTION:

A full wave rectifier passes _____ into positive cycles.

A.

Lower half cycle

B.

Upper half cycle

C.

Both cycles

D.

None of them

EXPLANATION

A full wave rectifier rectifies the whole wave, i.e. both the cycles (lower and upper)


QUESTION:

UV radiation is formed by bombarding gas molecules with

A.

Electron

B.

Protons

C.

Alpha rays

D.

Any of these

EXPLANATION

Ultraviolet radiation is produced by high-temperature surfaces, such as the Sun, in a continuous spectrum and by atomic excitation in a gaseous discharge tube as a discrete spectrum of wavelengths due to bmbardment of electrons.


QUESTION:

The role of inductance is equivalent to:

A.

Inertia

B.

Force

C.

Energy

D.

Momentum

EXPLANATION

Just like inertia tends to maintain its original state of motion or rest. Inductance does the same if it wants to maintain its state of the magnetic flux linking the conductor. Inertia resists any relative motion. Inductance also resists relative change in the magnetic flux linking the conductor.


QUESTION:

e/m ratio for an electron in electric and magnetic field is

A.

e/m =B r/E

B.

E/(B2r)

C.

E2/rB2

D.

B2/Er

EXPLANATION

It can be proven by dimensional analysis (comparing units of the variables on the left hand side and right hand side) that the only correct possible expression of the given options is that found in B.


QUESTION:

A body at temperature T radiates heat according to relation:

A.

T-2

B.

T4

C.

T-4

D.

None of these

EXPLANATION

By the Stefan-Boltzmann Law, for a black body, the amount of heat radiated per unit area is directly proportional to the fourth power of the kelvin temperature. The proportionality constant is called Stefen’s constant and has a value of 5.67x10(-8).


QUESTION:

In a rectifier, larger the value of hunt capacitor filter

A.

Larger the peak-to-peak value of ripple voltage

B.

Larger the peak current in the rectifying diode

C.

Longer the time that current pulse flows through the diode

D.

Smaller the voltage across the load

EXPLANATION

The time constant for a capacitor has the value RC, where R is the load resistance and C is the shunt capacitor’s capacitance. As C increases, RC increases so, it takes a longer time for the current pulse to flow through the diode.


QUESTION:

A sound wave has a wavelength of 0.20 m. What is the phase difference between two points along the wave which are 0.65 m apart?

A.

00

B.

450

C.

900

D.

1800

EXPLANATION

λ= 0.20m.

Phase difference= 0.65m

Nearest integral multiple of wavelength to phase difference= 0.20 x 3= 0.60m

Net phase difference = 0.65 - 0.60= 0.05m

In degrees = (phase difference/wavelength) x360

= (0.05/0.20) x 360= 90 degrees


QUESTION:

A 220 V main supply is connected to a resistance of 100 k ohms. The effective current is

A.

2.2mA

B.

2.2/√2 mA

C.

2.2 x √2 mA

D.

None of the above

EXPLANATION

By Ohm’s law; V=IR

Irms = Vrms/R = 220/100x10(3) = 2.2x10(-3) A= 2.2mA


QUESTION:

Oil droplets of mass m and charge q are dropped between two horizontal parallel plates. Air resistance is negligible. The droplets are falling at
constant velocity when electric field strength between the plates is E. Which of the following is true?

A.

E=O

B.

E < mg / q

C.

E=mg / q

D.

E > mg / q

EXPLANATION

If particle moves with constant velocity, by Newton’s laws, net force (ΣF) is zero.

ΣF= Electric force + gravitational force = 0

Magnitude of electric force = Magnitude of gravitational force

Q x E = m x g

E= (mg)/Q


QUESTION:

The X-ray photon is uncertain when it is

A.

Emitted

B.

Absorbed

C.

Travelling 

D.

All of these

EXPLANATION

Since an X-ray photon has a large momentum (by the de Broglie relation), its uncertainty in momentum is low, but the uncertainty of position is very high by Heisenberg’s uncertainty principle. Hence at all times, we are uncertain of its position in space.


QUESTION:

A force F = (0.Sx +10) N acts on a particle. Calculate the work done by the force in displacing particle from x=0 to x=2 m.

A.

20 J

B.

21 J

C.

22 J

D.

23 J

EXPLANATION

Explanation is given below.


QUESTION:

A stationary wave is setup on a string which is fixed at both ends. The frequency of the wave is 400 Hz. If the speed of wave is 480 m/s, then what is the length of the string?

A.

1.2 m

B.

0.84 m

C.

0.60m

D.

0.42 m

EXPLANATION

v= f x λ

λ = v/f = 480/400= 1.2 m

For the first harmonic,

2L= λ,

L= λ/2= 1.2/2= 0.6 m


QUESTION:

The ionization power of ____ ray is highest.

A.

Beta

B.

Gamma 

C.

He- Ne laser

D.

None of these

EXPLANATION

Alpha particles have the highest ionising particles.


QUESTION:

Calculate the time taken for the charges to complete the circuit, if the total charges were 5000 Coulomb and the current of the circuit was 20 Amp?

A.

250 seconds

B.

350 seconds

C.

400 seconds

D.

500 seconds

EXPLANATION

I = ΔQ/Δt

Δt= ΔQ/I = 5000/20 = 250 seconds.


QUESTION:

Instantaneous velocity for a displacement function d(t)= 2-2t at any time is given by

A.

-2t

B.

2t

C.

2

D.

-2

EXPLANATION

Explanation is given below.


QUESTION:

During an adiabatic process, pressure of gas is found to be proportional to the cube of its temperature. The ratio of Cp/Cv is

A.

1.5

B.

44319

C.

44257

D.

44289

EXPLANATION

Answer: 1.5


QUESTION:

The angular acceleration has units

A.

rad/sec

B.

sec/rad

C.

sec2

D.

None of these

EXPLANATION

Units of angular acceleration are rad/s2


QUESTION:

Fact 1: Ayesha said, Hamza and I both have cats.
Fact 2: Hamza said, I dont have a cat.
Fact 3: Ayesha always tells the truth, but Hamza sometimes lies.
If the above three statements are facts, then which of the following statements will also be a fact
I. Ayesha has a cat
II. Hamza has a cat
III. Hamza is lying
IV. All the statement are facts.

A.

Only I

B.

Only II

C.

Only III

D.

Statement 4

EXPLANATION

Based on fact 3, since Ayesha does not lie, Ayesha’s statement in fact 1 must be true. This means that Ayesha and Hamza both do have a cat. Hence statements I and II are deemed correct. Moreover, since Hamza does have a cat, while stating fact 2, he must be lying hence, statement III is also correct and therefore, statement 4 is correct.


QUESTION:

Statement:
There has been an unprecedented increase in the number of successful candidates in this years School Leaving Certificate Examination.
COURSE OF ACTION:
I. The government should make arrangements to increase number of seats of intermediate courses in existing college.
II. The government should take active steps to open new colleges to accommodate all these successful candidates.

A.

Both of them follow

B.

None of them follow

C.

Only I follows

D.

Only II follows

EXPLANATION

Since the number of graduating/leaving candidates are greater, more applicants will be eligible for seats in colleges. The government should therefore accommodate these applicants. Thus, both statements follow.


QUESTION:

Statements
I. She topped in her collage
II. She is hard-working

A.

Both statements are of some common cause

B.

 Statement 1 is the cause and 2 is its effect

C.

Statement 2 is the cause then 1 is its effect.

D.

Both of the statements are effect of independent causes

EXPLANATION

In order for her to top in her college, she must work hard. Hence, statement 2 is the cause and statement 1 is the effect.


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 the fruits, even if they 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

EXPLANATION

Curbing the free market by imposing high taxation on foreign commodities results in a decrease in quality and supply. Hence, the first statement does not follow.
The fruit vendors are not responsible for the fate of the indigenous fruits and, will only suffer if statement 2 is imposed. Hence, the second statement also does not follow.


QUESTION:

What should come next to Confound, Illiterat, Bewilder,... ?

A.

Kind

B.

Unlearned

C.

Normal

D.

Disable

EXPLANATION

Since confound and bewilder are synonyms, “illiterate” and the answer to the question must be synonyms. Hence, the correct answer is “unlearned”.


QUESTION:

First step in graphing linear equation is to

A.

Connect two points

B.

Extend a straight line

C.

Identify and plot coordinates

D.

Both A and B

EXPLANATION

To graph a linear equation, we firstly identify and plot coordinates, then join two plots and then extend the line.


QUESTION:

Complete the series ACD, AGD, AJD,____? 

A.

ALD

B.

ATD

C.

AND

D.

AMD

EXPLANATION

NOTE: INCORRECT QUESTION. THE CORRECT ANSWER IS “ALD”


QUESTION:

What was the name of Imam Bukhari (R.A)?

A.

Muhammad bin Ismail

B.

Muhammad Ismail

C.

Muhammad Ibrahim

D.

Both A and B

EXPLANATION

Imam Bukhari (R.A) was an Islamic scholar whose name was Muhammad bin Ismail al-Bukhari.


QUESTION:

If- means +, + mean -, x mean + and + mean x then which of the following will be the correct equation?

A.

30 + 5 + 14 - 10 x 15 = 122

B.

10 + 5 - 14 ÷ 10 x 15 = 158

C.

30 - 5 + 14 ÷ 10 x 15 = 162

D.

30 x 5 - 4 ÷ 10 + 15 = 31

EXPLANATION

When we rectify option D based on the stated rules, the left-hand side is transformed to;

30/5 + 4 x 10 - 15
Applying BODMAS;
6 + 40 -15 = 31
Since the left-hand side and right-hand side of D are equal, the equation is correct. All other options are incorrect.


QUESTION:

Complete the series A3.3, B6.6, C9.9, ______?

A.

D13.4

B.

D13.2

C.

D13.1

D.

D13.3

EXPLANATION

The alphabets increase in consecutive succession; i.e. A, B, C, D, E…
Meanwhile, the numbers are successive integral multiples of 3.3 i.e.; (3.3 x 1), (3.3 x2), (3.3 x 3), (3.3 x 4). Hence, D13.2 is the next logical step in the series.


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