For the stability of the organic compounds, Oparin opined that probably:
1. UV radiation never reached the surface of the primeval Earth
2. the primitive Earth was in a molten state
3. the primitive Earth atmosphere was reducing rather than oxidizing
4. plenty of energy sources were available for chemical reactions to occur
Adenine was synthesized by Orgel, using the Miller apparatus, when he used the gas :
1. carbon dioxide
2. hydrogen cyanide
3. hydrogen sulfide
4. nitrogen
The first genetic code of life was based on :
1. DNA
2. RNA
3. Proteins
4. Lipids
Both Charles Darwin and A.R.Wallace were influenced by the:
1. writings of J.B.S.Haldane on the origin of life
2. findings of Urey and Miller experiments
3. findings on the Galapagos Islands
4. essay on human population by T.R.Malthus
Aquatic mammals do not contain gill slits because:
1. they are fishes and not mammals
2. they only float on the water
3. their adaptation to aquatic life is secondary
4. they respire through their moist skins and lungs
What is the ultimate source of genetic variability?
1. mutation
2. migration
3. genetic drift
4. nonrandom mating
de Vries based his “Mutation Theory” on his observation on :
1. Pisum sativum
2. Drosophila melanogaster
3. Oenothera lamackiana
4. Coenorhabditis elegans
According to the modern view of Darwinism, the unit of natural selection is the :
1. population
2. individual
3. species
4. community
If there are two forms of a specific enzyme in a population, and if the relative frequencies of the individuals possessing each form of the enzyme changes, then certainly there is :
1. mutation
2. genetic drift
3. gene migration
4. evolution
The cause of the high incidence of the allele of sickle cell anaemia in human population is due to :
1. genetic drift
2. natural selection
3. bottleneck effect
4. founder effect
Which of the following is the most important precondition for speciation to occur?
1. reproductive isolation
2. a crash of the population size
3. adaptive radiation
4. random mating
Which of the following pairs of organs do not represent analogous organs?
1. Eye of an octopus and eye of a mammal
2. Flippers of penguin and flippers of dolphin
3. Wings of bat and forelimbs of humans
4. Wings of birds and wings of butterfly
“Organisms that share common descent show underlying embryological patterns on which they build later their adult patterns”. This is :
1. Haeckel’s law
2. Baer’s law
3. Gauss law
4. Allen’s rule
The only evolutionary agent that produces adaptive evolutionary changes is :
1. Non random mating
2. Mutation
3. Genetic drift
4. Natural selection
A population of an animal is hunted down to only 20 organisms. Later the number is restored to 10,000 organisms, but the variations in this population are highly reduced. This is called :
1. Founder effect
2. Bottleneck effect
3. Edge effect
4. Heterosis
The struggle for existence is a consequence of :
1. each organism leaving more organisms than needed to replace itself
2. innate competitive tendencies
3. the inevitable difficulty of coping with climatic conditions
4. territories and dominance hierarchies
After pollution destroyed lichens on the trees, the survival of the dark-colored peppered moths increased, because they were :
1. protected from carcinogens
2. protected from lichen poisons
3. more robust
4. protected from predation
Many bacteria are now resistant to penicillin, because:
1. penicillin causes gene mutations, some of which are beneficial
2. previously resistant forms survived and reproduced better than non-resistant forms
3. the hospital environment inhibits competition among bacteria
4. penicillin triggers the synthesis of resistant proteins
A change in allele frequency within a population, over a succession of generations , is called :
1. microevolution, or adaptive evolution
2. macroevolution, or speciation
3. coevolution
4. phylogenetic evolution
If a new allele suddenly becomes very abundant in a population, most likely it is :
1. mutating rapidly
2. flowing with emigrants
3. strongly selected for
4. a product of assortative mating
Natural selection is best defined as occurring when the environment causes :
1. differential success in reproduction
2. differential mortality
3. assortative mating
4. a reduced gene pool
In allopatric speciation, initial barrier to gene flow is :
1. behavioral
2. postzygotic
3. geographic
4. ecological
Which one of the following populations would most quickly lead to two groups with few shared traits?
1. a population with disruptive selection
2. a population with directional selection
3. a population with stabilizing selection
4. a population with no selection
Which one of the following would cause the Hardy-Weinberg principle to be inaccurate?
1. | The size of the population is very large. |
2. | Individuals mate with one another at random. |
3. | Natural selection is present. |
4. | There is no source of new copies of alleles from outside the population. |
Why is genetic polymorphism important to evolution?
1. | individual variability provides the raw material for natural selection to act on |
2. | genes cannot mutate unless they are polymorphic |
3. | only heterozygous individuals are selected in natural populations |
4. | the Hardy-Weinberg equilibrium is less likely to be disturbed in polymorphic populations |
The genetic material must show variation. Which of the following is NOT an example of genetic variation?
1. New mutations can occur during meiosis.
2. Different species have different numbers of chromosomes.
3. Different individuals within a species have different phenotypes.
4. Individuals of different species may have similar phenotypes.
Why might heat-killed bacteria be useful as a vaccine?
1. It can cause a lethal infection.
2. Heat degradation of proteins changes their shape.
3. Molecules from the cell surface are still intact and can provoke an immune response.
4. DNA molecules can transform other strains of bacteria.
Why was the DNase treatment used by Avery, MacLeod, and McCarty an important step?
1. This allowed them to isolate pure DNA samples.
2. This allowed them to isolate pure protein samples.
3. This allowed them to demonstrate that removing the DNA prevents transformation.
4. This allowed them to demonstrate that mixing rough cells with DNA prevents transformation.
What key characteristic of T2 bacteriophage allowed Hershey and Chase to use it in their studies of the genetic material?
1. Its genes encode proteins that assemble to produce the viral coat.
2. It injects its genetic material into a bacterial cell.
3. It can undergo either the lytic or lysogenic life cycle.
4. It enters the bacterial cell to cause infection.
Which of the following statements about the structure of DNA is incorrect?
1. One complete turn requires 3.4 nm and 10 base pairs.
2. The backbones of each strand run in opposite directions relative to each other.
3. Each pair of nucleotides is held together by three hydrogen bonds.
4. The width of the molecule is a constant 2nm.
Which of the following structures of a eukaryotic chromosome is not primarily composed of DNA?
1. Telomeres.
2. Origin of replication.
3. Kinetochore.
4. Centromere.
Which statement about bacterial DNA replication is correct?
1. DNA replication begins at several places along the chromosome.
2. DNA replication begins at the origin and travels in both directions.
3. DNA replication begins at the origin and travels around the chromosome back to the origin.
4. DNA replication begins at a GC rich region of the chromosome.
What is a key difference between DNA pol III and DNA ligase?
1. Only DNA polIII synthesizes phosphoester bonds.
2. Only DNA ligase synthesizes phosphoester bonds.
3. DNA polIII can synthesize DNA from 3'-5'.
4. DNA ligase can use energy from ATP rather than nucleotides.
Which statement could NOT describe both eukaryotic and prokaryotic transcription?
1. Promoter elements in the DNA are required for polymerase binding.
2. Transcription factors control the binding of RNA polymerase.
3. RNA polymerase opens a double stranded DNA to expose the template strand.
4. RNA polymerase catalyzes RNA synthesis from 3' to 5' of the new strand
Which of these is an enzymatic function of the ribosome?
1. Polynucleotide kinase.
2. Base pair recognition.
3. Methyl transferase.
4. Peptidyl transferase.
Which of the following facts is the most important evidence that the genetic code is a triplet code?
1. Insertions or deletions caused significant defects in protein structure.
2. The effect of single insertions could be remedied by single deletions nearby.
3. Two nearby insertions caused significant defects in protein structure.
4. Three insertions near each other often led to minor defects in protein structure.
Which of the following would you expect to find in an inducible system?
1. A repressor protein, which is bound to DNA in absence of any other factor.
2. A repressor protein, which is bound to DNA in the presence of a corepressor.
3. An activator protein, which is bound to DNA in absence of any other factor.
4. An activator protein, which is bound to DNA only in the absence of an inhibitor.
The famous double-helix model of DNA was proposed by Watson and Crick in ____ and they shared Nobel Prize for Physiology or Medicine in ________ for their effort.
1. 1951, 1971
2. 1943, 1963
3. 1953, 1962
4. 1969, 1972
Which of the following was not a character studied by Mendel in garden pea?
1. Flower position
2. Pod shape
3. Flower colour
4. Pod position
A genetic cross between homozygous individuals but with different alleles for a single gene of interest is called as:
1. A reciprocal cross
2. Monohybrid cross
3. Dihybrid cross
4. Test cross
What proportion of progeny in F2 generation in a Mendel monohybrid cross resembled the parent [of P generation] that expressed the recessive trait?
1. ¼
2. ½
3. ¾
4. 2/3
In a test cross, the plant expressing the dominant phenotype is crossed with the plant:
1. Which is heterozygous dominant
2. Which is heterozygous recessive
3. Which is homozygous recessive
4. Which is homozygous dominant
Which of the following is not true for the Law of Dominance given by Mendel?
1. | Characters are controlled by discrete units called factors. |
2. | Factors occur in pairs. |
3. | In a dissimilar pair of factors one member of the pair dominates the other. |
4. | The alleles show blending at the time of fertilization |
A heterozygous plant produces:
1. Only one kind of gamete
2. Two kinds of gametes each having one allele with equal proportion.
3. Two kinds of gametes each having two alleles with equal proportion.
4. Two kinds of gametes each having one allele with one allele occurring in more gametes than the other.
What is the F2 phenotypic ratio in cases of incomplete dominance?
1. 1 : 1
2. 3 : 1
3. 1 : 2 : 1
4. 1 : 1
Blood group antigens are:
1. Carbohydrates present in plasma
2. Carbohydrates present on the surface of RBCs
3. Plasma proteins
4. Proteins present on the surface of RBCs
What can be the blood groups of progeny whose father and mother are of AB and O blood group respectively?
1. A and B only
2. AB only
3. All except O
4. A, B, AB and O
To study whether a gene exhibits multiple allelism or not one must study:
1. An individual
2. A population
3. A species
4. With concentration
Occasionally, a single gene product may produce more than one effect. Such a gene is said to be:
1. Pleiotropic
2. Polygenic
3. Psuedoallele
4. Housekeeping
‘When two pairs of traits are combined in a hybrid, segregation of one pair of characters is independent of the other pair of characters’. This is the statement of:
1. Law of Dominance
2. Law of segregation
3. Law of Independent Assortment
4. Law of Linkage
Mendel’s work remained unrecognized till 1900. Which of the following was not a reason for this?
1. His work was widely publicized and it brought bad name to Mendel
2. His concept of factors as stable and discrete units that did not ‘blend’ was not accepted.
3. His approach of using mathematics to explain biological phenomena was unacceptable.
4. He could not provide any physical proof for the existence of factors or say what they were made of.
“Chromosomes, which are seen in all dividing cells and pass from one generation to the next, are the basis for all genetic inheritance”.
This statement is credited to:
1. Watson and Crick
2. Hershey and Chase
3. Sutton and Boveri
4. Meselson and Stahl
When the two genes in a dihybrid cross are situated on the same chromosome:
1. The proportion of parental gene combinations was much higher than the non-parental type.
2. The proportion of parental gene combinations was much lesser than the non-parental type.
3. The proportion of parental gene combinations was equal to the non-parental type.
4. Only recombinants are formed.
The mechanism of sex determination in grasshoppers is:
1. XX – XY; male heterogamety
2. XX – XY; female heterogamety
3. XX – XO; male heterogamety
4. XX – XO; female heterogamety
During his observation of spermatogenesis in a few insects, Henking found that a nuclear structure was received by 50 % of the sperms. What did he call this structure?
1. X – body
2. Y – body
3. X – chromosome
4. Y – chromosome
It is unfortunate that in our society women are blamed for producing female children and have been ostracised and ill-treated because:
1. The sex is determined by the type of sperm fertilizing the egg
2. The sex is determined by the type of egg fertilizing the sperm
3. The sex is determined by the hormones produced by the fetus
4. The sex is determined by God’s Will
Mendelian disorders are mainly determined by:
1. Alteration or mutation in a single gene.
2. Chromosomal gross structural changes.
3. Recombination between linked genes.
4. Jumping genes
The family pedigree of Queen Victoria shows a number of haemophilic descendants as she was:
1. Affected by the disease
2. Carrier for the disease
3. Did not carry the allele for haemophilia
4. Was not a queen
The point mutation leading to sickle cell anaemia occurs:
1. at sixth position in the beta chain of haemoglobin
2. at sixth position in the alpha chain of haemoglobin
3. at sixth position in the beta chain of myoglobin
4. at sixth position in the alpha chain of myoglobin
In cases of Phenylketonuria:
1. The affected individual lacks an enzyme that converts the amino acid tyrosine into phenylalanine.
2. The affected individual makes an enzyme that converts the amino acid tyrosine into phenylalanine.
3. The affected individual makes an enzyme that converts the amino acid phenylalanine into tyrosine.
4. The affected individual lacks an enzyme that converts the amino acid phenylalanine into tyrosine.
Monosomy means:
1. Lack of one pair of chromosomes
2. Lack of one of any one pair of chromosome
3. Presence of an extra chromosome
4. Presence of an extra set of chromosomes
An individual affected with Turner’s Syndrome:
I. Is a female
II. Has 45 chromosomes
III. Has rudimentary ovaries
Of the above statements, the correct statements are:
1. Only I and II
2. Only I and III
3. Only II and III
4. I, II and III
Which of the following is a pyrimidine base found in DNA?
1. Adenine
2. Guanine
3. Uracil
4. Cytosine
In a strand of a nucleic acid, two nucleotides are linked together by:
1. 3’ – 5’ phosphodiester bond
2. 5’ – 3’ phosphodiester bond
3. 2’ – 5’ phosphodiester bond
4. 3’ – 1’ phosphodiester bond
The backbone of a polynucleotide chain is made of:
1. Sugar and nitrogenous bases
2. Phosphate and nitrogenous bases
3. Sugar and phosphate
4. Sugar, phosphate, and nitrogenous bases
According to Erwin Chargaff, for a double stranded DNA
1. The ratios between Adenine and Thymine, and , Guanine and Cytosine are constant and equals one.
2. The ratios between Adenine and Thymine, and , Guanine and Cytosine are constant but is not equal to one.
3. The ratios between Adenine and Guanine, and , Thymine and Cytosine are constant and equals one.
4. The ratios between Adenine and Guanine, and , Thymine and Cytosine are constant but is not equal to one.
Histones are:
1. Positively charged and basic amino acids
2. Negatively charged and basic proteins
3. Positively charged and acidic proteins
4. Not found in bacteria
Transcriptionally active chromatin is termed as:
1. Heterochromatin
2. Euchromatin
3. Prechromatin
4. Prochromatin
In Griffith experiment, which of the following bacterial strains were capable of causing pneumonia in mice?
1. Live R
2. Bacteria strain without polysaccharide coat
3. Heat Killed S
4. Live R without capsule and Heat Killed S
The unequivocal proof that DNA is the genetic material was provided by:
1. Avery, Macleod and McCarty
2. Hershey and Chase
3. Meselson and Stahl
4. Watson and Crick
A molecule that can act as a genetic material must fulfill all the following criteria except:
1. It should be able to generate its replica
2. It should chemically and structurally be stable
3. It should provide scope for rapid mutations
4. It should be able to express itself in the form of “Mendelian Characters”
Reverse transcriptase is a:
1. DNA dependent RNA polymerase
2. RNA dependent DNA polymerase
3. RNA dependent RNA polymerase
4. DNA dependent DNA polymerase
DNA replication is correctly described as:
1. Semi-conservative and Continuous
2. Semi-conservative and Discontinuous
3. Conservative and Continuous
4. Semi-conservative and Semi-discontinuous
In a transcription unit, with respect to structural gene, the promoter is located:
1. Upstream and 5’
2. Upstream and 3’
3. Downstream and 5’
4. Downstream and 3’
In most prokaryotes, the transcription unit is:
1. Mono-cistronic
2. Poly-cistronic
3. Multi-cistronic
4. Uni-cistronic
The process of RNA splicing shows the dominance of:
1. DNA world
2. RNA world
3. Protein world
4. Microbial world
Whose cell free system finally helped the genetic code to be deciphered?
1. Gamow
2. Severo Ochoa
3. Hargobind Khorana
4. Marshall Nirenberg
Which of the following is not a stop codon?
1. UAA
2. UGA
3. UAC
4. UAG
Which of the following anticodons will hybridize with the mRNA codon 5’ – AUG – 3’?
1. 5’ – UAC – 3’
2. 5’ – TAC – 3’
3. 3’ – UAC – 5’
4. 3’ – TAC – 5’
Hisardale a new breed of sheep developed in Punjab by crossing Bikaneri ewes and Merino rams is an example of
1. Outcrossing
2. Cross-breeding
3. Interspecific hybridisation
4. Outbreeding
In poultry, coccidiosis is caused by
1. Virus
2. Fungus
3. Helminth parasite
4. Protozoan
Which of the following are edible marine fishes?
1. Catla, Rohu, Clarias
2. Hilsa, Mackerels, Pomfrets
3. Heteropneustes, Wallago, Catla
4. Labeo, Calbasu, Singhi
Which of the following is not true ?
1. Fish meal is rich source of protein for cattle and poultry
2. Fish meal is produced from the non-edible parts of fishes
3. Silver revolution is increases in fish production
4. Shagreen is the skin of shark
Choose incorrect option :
1. More than 70 % of world livestock population is in India and China
2. Milk yielding capacity of buffaloes is three times more as compared to cows
3. Buffalo milk is superior to cow milk with respect to fat and mineral content
4. Continuous inbreeding increases the productivity of milk
Major drawback of inbreeding is
1. Increase in homozygosity
2. Decrease in immunity
3. Reduction in fertility
4. Increase in food consumption
Project artificial insemination in cattle breeding was initiated at
1. IVRI, izzatnagar, UP
2. NDRI, Karnal
3. NDRI, Kerala
4. CDC, Lucknow
Which of the following is not true regarding honey bee ?
1. Drones are produced by arrhenotoky
2. Queen is produced by syngamy
3. Workers are sterile females, produced by thelytoky
4. Worker bees are the smallest members of honey bee colony
Rearing pond in culture fishery is used in which of the following process
1. Hatching of egg
2. Nursing of fries
3. Rearing fingerlings
4. Induced breeding
Silk obtained from the silk worm cocoon has ___ protein is ___structure
1. Fibroin, Triple helical
2. Fibroin, parallel -pleated sheet
3. Keratin, -helix
4. Fibroin, anti-parallel -pleated sheet
A : MOET increases herd size in short time with desirable trait
R : MOET involves production of 6-8 eggs per cycle by inducing follicular maturation and superovulation
Major product for the reactionis-
1.
2.
3.
4.
What are A & B in the following reaction
1. | ![]() |
2. | ![]() |
3. | ![]() |
4. | None of these |
What is product of the following reaction ?
Which of the following bromides is the major product of the reaction shown below, assuming that there are no carbocation rearrangement
Benzyne intermediate is not observed in -
1.
2.
3.
4.
Compounds A and B are, respectively:
A | B | |
1. | ||
2. | ||
3. | ||
4. |
? Product is-
If the starting material is 1-methyl-1,2-epoxy cyclopentane, of absolute configuration, decide which one compound correctly represent the product of its reaction with sodium methoxide in methanol.
The correct order of reactivity towards electrophilic substitution is -
1. Phenol > Benzene > Chlorobenzene
> Benzoic acid
2. Benzoic acid > Chlorobenzene > Benzene
> Phenol
3. Phenol > Chlorobenzene > Benzene
> Benzoic acid
4. Benzoic acid > Phenol > Benzene
> Chlorobenzene
is converted to
by
(i) | (ii) | (iii) | |
1. | CH3 – MgI, H3O+ | H2SO4, ∆ | HBr, R2O2 |
2. | CH3 – MgI, H3O+ | H2SO4, ∆ | HBr |
3. | CH3 – MgI, H3O+ | HBr | |
4. | HBr, R2O2 | CH3 – MgI, H3O+ |
The product 'B' in the below mentioned reaction is:
1. | 2. | ||
3. | 4. | None of these |
?
Major product is -
? Product is -
Which is/are correct statements ?
These bonds are affected in esterfication
1. 1 and 4
2. 1 and 2
3. 1, 2 and 3
4. 1, 2, 3 and 4
CH3–CH2–CHO + dil NaOH gives X
What is product X in the above reaction?
1. | |
2. | |
3. | |
4. |
In the Cannizzaro reaction given below –
the slowest step is -
1. The attack of OH¯ at the carbonyl group
2. The transfer of hydride to the carbonyl group
3. The abstraction of proton from the carboxylic group
4. The deprotonation of Ph - CH2OH
(Y is alcohol, D is deuterium)
X and Y will have structure –
1. | ![]() |
2. | ![]() |
3. | ![]() |
4. | None of the above |
Alkaline hydrolysis of C4H8Cl2 gives a compound (A) which on heating with NaOH and I2 produces a yellow precipitate of CHI3.The compound (A) should be:
1.
2.
3.
4.
–CH2–CH2 –CH2–CH2–OH is converted into by –
1. (i) KMnO4 (ii) H+, H
2. (i) Na2Cr2O7 (ii) H+,
3. (i) Ag2O (ii) H+,
4. All of these
, on saponification of the given ester is formed –
1. and OHC-CHO
2. OH–CH2–CH2–OH and OHC–COOH
3. and HOOC–COOH
4. HO–CH2–CH2–COOH and HCOOH
On hydrolysis, a sweet-smelling ester A , with a molar mass of 116, produces a carboxylic acid and an alcohol. Alcohol gives a positive iodoform reaction. The formula for A will be:
1. | |
2. | CH3CH2–O–COC3H7 |
3. | CH3–O–COC4H9 |
4. |
Y
X and Y are -
1. in both case
2. in both case
3.
4. Formation of A and B is not possible
, X is-
Which of the following reaction does not give 1° amine as final product
1.
2.
3.
4.
, final product P is
Which of the following is not correct–
1. Ethyl amine & aniline both have NH2 group
2. Ethyl amine & aniline both dissolve in HCl
3. Ethyl amine & aniline both react with CHCl3 & KOH to form unpleasent gas
4. Ethyl amine and aniline both react with HNO2 to give hydroxy compound
Dipole moment of which of the following is highest-
1. Ether
2. Alcohol
3. Halo alkane
4. Nitro alkane
. A and B are -
1. CH3–CH2–NO2, CH3–CH2–O–N=O
2. CH3–CH2–O–N=O, CH3–CH2–NO2
3. Both are CH3–CH2–NO2
4. Both are
The change in optical rotation with time of freshly prepared solution of sugar is known as–
1. Specific rotation
2. Inversion
3. Rotation
4. Mutarotation
compound X is -
1. 2-Chloroethamenitrile
2. 2-Bromoethanenitrile
3. Both A & B
4. Acetic acid
1. Anomers
2. Epimers
3. Enantiomers
4. Diastereoisomers
Cellulose upon acetylation with excess acetic anhydride/H2SO4 (catalytic) gives cellulose triacetate whose structure is –
Write the structure of alanine at pH = 2 and
pH = 10
1.
2.
3.
4. None of above
The destruction of the biological nature and activity of proteins by heat or chemical agent is called–
1. dehydration
2. denaturation
3. denitrogenation
4. deammination.
Which of the following is an elastomer ?
1. Vulcanized rubber
2. Dacron
3. Polystyrene
4. Melamine
Dacron is an example of–
1. Elastomer
2. Fibre
3. Polyamide
4. Thermoaddition polymer
Nylon-66 is obtained by condensation polymerization of–
1. Adipic acid and hexamethylene diamine
2. Phenol and formaldehyde
3. Terephthalic acid and ethylene glycol
4. Sebacic acid and hexamethylene diamine.
The monomer of PMMA is–
1. Methyl methacrylate
2. Ethyl acrylate
3. Acrylonitrile
4. Methyl acrylate
Which of the following is correct statement for a substance to act as dye?
1. Presence of chromophore is necessary
2. Presence of auxochrome group as well as chromophore is necessary
3. Every coloured substance
4. All the above
Hypnotic drug among the given options is:
1. Metaldehyde
2. Acetaldehyde
3. Paraldehyde
4. None of these
Morphine is
1. Antiseptic
2. Analgesic
3. Antibiotic
4. Anesthetic
Sulpha drugs are used for:
1. Removing bacteria.
2. Precipitating bacteria.
3. Stopping the growth of bacteria.
4. Decreasing the size of bacteria.
Chemical that can acts as monopropellant among the following options is:
1.
2.
3. Kerosene
4. Alcohol
A 220 - volt input is supplied to a
Transformer. The output circuit draws a
current of 2.0 ampere at 440 volts. If the
efficiency of the transformer is 80%, the
current drawn by the primary windings of
the transformer is:-
1. 5.0 ampere
2. 3.6 ampere
3. 2.8 ampere
4. 2.5 ampere
An ac voltage is applied to a resistance R and
an inductor L in series. If R and the inductive
reactance are both equal to 3, the phase
difference between the applied voltage and the
current in the circuit is :-
1. /6
2. /4
3. /2
4. Zero
In an ac circuit an alternating voltage
e = 200 sin 100 t volts is connected to a
capacitor of capacity 1μF. The r.m.s. value of
the current in the circuit is :-
1. 10 mA
2. 100 mA
3. 200 mA
4. 20 mA
In an electrical circuit R, L, C and an a.c.
voltage source are all connected in series.
When L is removed from the circuit, the phase
difference between the voltage and the current
in the circuit is /3. If instead, C is removed
from the circuit the phase difference is again
/3. The power factor of the circuit is :
1. 1
2.
3.
4.
A sinusoidal voltage V(t) = 100 sin(500t) is applied across a pure inductance of L= 0.02 H. The current through the coil is :
1. 10 cos (500 t)
2. -10 cos(500t)
3. 10 sin (500t)
4. -10 sin (500t)
A \(50\) Hz AC source of \(20\) volts is connected across \(R\) and \(C\) as shown in the figure below.
If the voltage across \(R\) is \(12\) volts, then the voltage across \(C\) will be:
1. | \(8\) V |
2. | \(16\) V |
3. | \(10\) V |
4. | not possible to determine unless values of \(R\) and \(C\) are given |
In an ideal parallel LC circuit, the capacitor is charged by connecting it to a dc source which is then disconnected. The current in the circuit will:
1. Become zero instantaneously.
2. Grow monotonically.
3. Decay monotonically.
4. Oscillate instantaneously.
A conducting circular loop is placed in a
uniform magnetic field, B = .025 T with its
plane perpendicular to the loop. The radius
of the loop is made to shrink at a constant
rate of 1 mm s–1. The induced e.m.f. when
the radius is 2 cm, is :-
1. 2 V
2.
3.
4.
The current (I) in the inductance is varying with
time according to the plot shown in figure.
Which one of the following is the correct
variation of voltage with time in the coil ?
1.
2.
3.
4.
A circular disc of radius 0.2 meter is placed in a uniform magnetic field of induction in such way that its axis makes an
angle of 60° with . The magnetic flux linked
with the disc is :-
1. 0.08 Wb
2. 0.01 Wb
3. 0.02 Wb
4. 0.06 Wb
A coil of resistance 400 is placed in a
magnetic field. If the magnetic flux (Wb)
linked with the coil varies with time t (sec) as
= 50 t2 + 4. The current in the coil at t = 2 sec is :
1. 2A 2. 1A
3. 0.5A 4. 0.1A
1. | \(10\) mH |
2. | \(100\) mH |
3. | \(1\) mH |
4. | Cannot be calculated unless \(R\) is known |
The magnetic flux through a circuit of
resistance R changes by an amount in a
time t. Then the total quantity of electric
charge Q that passes any point in the circuit
during the time t is represented by :–
1.
2.
3.
4.
Voltage across each elements of a series LCR
circuit are given by VL= 60V, VC= 20V,VR= 30V
Find out source voltage.
1. 50V
2. 100V
3. 150V
4. 200V
A metallic ring is dropped down, keeping its
plane perpendicular to a constant and
horizontal magnetic field. The ring enters the
region of magnetic field at t = 0 and
completely emerges out at t = T sec. The
current in the ring varies as :-
1.
2.
3.
4.
I: | A small magnet takes a longer time in falling into a hollow metallic tube without touching the wall. |
II: | There is an opposition to motion due to the production of eddy currents in a metallic tube. |
Choose the correct option for the above statements:
1. | Both I and II are True and II is the correct explanation for I. |
2. | Both I and II are True and II is not the correct explanation for I. |
3. | I is True but II is False. |
4. | I is False but II is True. |
Statement-1 :- An inductor acts as a perfect
conductor for direct current.
Statement-1 :- The power factor of an
inductor is zero.
1. Statement-1 is true, statement-2 is true and
statement-2 is correct explanation for
statement-1.
2. Statement-1 is true, statement-2 is true and
statement-2 is NOT the correct explanation
for statement-1.
3. Statement-1 is true, statement-2 is false.
4. Statement-1 is false, statement-2 is true.
Two circuits have coefficient of mutual induction of 0.09 henry. Average e.m.f. induced in the secondary by a change of current from 0 to 20 ampere in 0.006 second in the primary will be
1. 120 V
2. 80 V
3. 200 V
4. 300 V
A coil is wound of a frame of rectangular cross-section. If the linear dimensions of the frame are doubled and the number of turns per unit length of the coil remains the same, then the self inductance increases by a factor of:
1. | \(6\) | 2. | \(12\) |
3. | \(8\) | 4. | \(16\) |
The ratio of amplitude of magnetic field to the
amplitude of electric field for an electromagnetic
wave propagating in vacuum is equal to:
1. The ratio of magnetic permeability to the
electric susceptibility of vacuum
2. Unity
3. The speed of light in vacuum
4. Reciprocal of speed of light in vacuum
The electric field of an electromagnetic wave
in free space is given by :
, where t and x
are in seconds and metres respectively. It can
be inferred that :-
(a) The wavelength is 188.4 m
(b) The wave number k is 0.33 rad/m
(c) The wave amplitude is 10 V/m
(d) The wave is propagating along +x direction
Which one of the following pairs of statements
is correct :-
1. (a) and (b)
2. (b) and (c)
3. (a) and (c)
4. (c) and (d)
The velocity of electromagnetic wave is parallel to:
1. \(\vec{B} \times \vec{E}\)
2. \(\vec{E} \times \vec{B}\)
3. \(\vec {E}\)
4. \(\vec{B}\)
In an electric circuit, there is a capacitor of reactance \(100~\Omega\) connected across the source of \(220~\text{V}\). The rms value of displacement current will be:
1. \(2.2~\text{A}\)
2. \(0.22~\text{A}\)
3. \(4.2~\text{A}\)
4. \(2.4~\text{A}\)
The magnetic field between the plates of a capacitor is given by for-
1.
2.
3.
4.
1. | \(10\) m/s2 |
2. | \(20\) m/s2 |
3. | \(5\) m/s2 |
4. | can't be determined |
A light ray is incident at an angle of \(30^{\circ}\) on a transparent surface separating two media. If the angle of refraction is \(60^{\circ}\), then the critical angle is:
1. \(\sin^{- 1} \left(\frac{1}{\sqrt{3}}\right)\)
2. \(\sin^{- 1} \left(\sqrt{3}\right)\)
3. \(\sin^{- 1} \left(\frac{2}{3}\right)\)
4. \(45^{\circ}\)
In the figure shown the angle made by the light ray with the normal in the medium of refractive index \(\sqrt{2}\) is:
1. \(30^{\circ}\)
2. \(60^{\circ}\)
3. \(90^{\circ}\)
4. None of these
A boy is 1.8m tall and can see his image in a
plane mirror fixed on a wall. His eyes are 1.6m
from the floor level. The minimum length of
the mirror to see his full image is–
1. 0.9 m
2. 0.85 m
3. 0.8 m
4. Can't be determined
A ray of light is incident on an equilateral glass prism placed on a horizontal table. For minimum deviation which of the following is true ?
1. PQ is horizontal
2. QR is horizontal
3. RS is horizontal
4 .Either PQ or RS is horizontal
A light ray passes from air into another
medium at point P. How long does it take
the light ray to travel from P to Q?
1. 9 × 10–10 s
2. 9 × 10–7 s
3. 9 × 10–8 s
4. 9 × 10–6s
A water drop in air refractes the light ray as
1.
2.
3.
4.
In Young's double-slit experiment, the slit separation is doubled. This results in:
1. | An increase in fringe intensity |
2. | A decrease in fringe intensity |
3. | Halving of the fringe spacing |
4. | Doubling of the fringe spacing |
A glass prism of refracting angle 60º gives a
minimum deviation of 30º. What is the
refractive index of the glass –
1. 1.5
2.
3.
4. can not be determined
A prism of refractive index has a refracting
angle of 30°. One of the refracting surfaces of
the prism is polished. A beam of monochromatic
light will retrace its path if its angle of incidence
on the refracting surface is
1. 0°
2. 30°
3. 45°
4. 60°
Assertion: For best contrast between maxima and minima in the interference pattern of Young's double slit experiment, the intensity of light emerging out of the two slits should be equal.
Reason: The intensity of interference pattern is proportional to square of amplitude.
A given ray of light suffers minimum deviation
in an equilateral prism P. Additional prisms Q
and R of identical shape and of the same
material as P are now added as shown in the
figure. The ray will now suffer
1. greater deviation
2. no deviation
3. same deviation as before
4. total internal reflection
A ray of light undergoes deviation of 30° when
incident on an equilateral prism of refractive index
. The angle made by the ray inside the prism
with the base of the prism is
1. 1
2. 2
3. 3
4. 0
In Young's double-slit experiment, the light emitted from the source has \(\lambda = 6.5\times 10^{-7}~\text{m}\) and the distance between the two slits is \(1~\text{mm}.\) The distance between the screen and slits is \(1~\text m.\) The distance between third dark and fifth bright fringe will be:
1. \(3.2~\text{mm}\)
2. \(1.63~\text{mm}\)
3. \(0.585~\text{mm}\)
4. \(2.31~\text{mm}\)
White light is used to illuminate the two slits in Young's double slit experiment, separation between the slits is b and the screen is at a distance d(>>b) from the slits. At a point on the screen, directly in front of the slits, certain wavelengths are missing. Some of these missing wavelengths are
1.
2.
3.
4.
Angular width of central maximum in the Fraunhoffer's diffraction pattern is measured. Slit is illuminated by the light of another wavelength 6000 Å due to which angular width decreases by 30%. Wavelength of light used is-
1. 4200 Å
2. 8571 Å
3. 4700 Å
4. 6000 Å
In a two slit experiment with monochromatic light, fringes are obtained on a screen placed at some distance from the slits. If screen is moved by 5 × 10–2 m towards the slits, then change in fringe width is 3 × 10–5 m. If the distance between slits is 10–3 m then wavelength of the light used will be
1. 4000 Å
2. 6000 Å
3. 5890 Å
4. 8000 Å
Interference fringes from sodium light (1 = 5890 Å) in a double slit experiment have an angular width 0.20o. To increase the fringe width by 10%, wavelength of light used should be
1. 5892 Å
2. 4000 Å
3. 8000 Å
4. 6479 Å
In a Young's double slit experiment two narrow slit 0.8 mm apart are illuminated by the same source of yellow light ( 5893 Å). If distance between slits and screen is 2m then separation between adjacent bright lines will be
1. 14.73 mm
2. 14.73 cm
3. 1.473 mm
4. 147.3 mm