AIIMS Full Mock Test 12


200 Questions MCQ Test AIIMS Mock Tests & Previous Year Papers | AIIMS Full Mock Test 12


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This mock test of AIIMS Full Mock Test 12 for NEET helps you for every NEET entrance exam. This contains 200 Multiple Choice Questions for NEET AIIMS Full Mock Test 12 (mcq) to study with solutions a complete question bank. The solved questions answers in this AIIMS Full Mock Test 12 quiz give you a good mix of easy questions and tough questions. NEET students definitely take this AIIMS Full Mock Test 12 exercise for a better result in the exam. You can find other AIIMS Full Mock Test 12 extra questions, long questions & short questions for NEET on EduRev as well by searching above.
QUESTION: 1

As the speed of a fan increases, current drawn

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QUESTION: 2

An electron remains undeflected when passing perpendicular to mutually perpendicular electric and magnetic fields. If the magnetic field is 8 Gauss and elecric field is 4000 V/m, the velocity of the electron is

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QUESTION: 3

A photon of energy 4 eV is incident on a metal surface whose work function is 2 eV. Minimum value of reverse potential to be applied for stopping the emission of electrons is

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QUESTION: 4

Two balls at same temperature collide. What is conserved ?

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QUESTION: 5

If momentum of a particle is doubled, then its de-Broglie's wavelength will

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QUESTION: 6

Which of the following electromagnetic waves has minimum frequency ?

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QUESTION: 7

The potential difference across the terminals of a battery is 50V when 11A current is drawn and 60V when 1A current is drawn. The e.m.f. and the internal resistance of the battery are

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QUESTION: 8

In Millikan oil drop experiment a drop of charge Q and radius r is kept constant between two plates of potential difference of 800 volt. Then charge on other drop of radius 2r which is kept constant with a potential difference of 3200 V is

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QUESTION: 9

Equivalent capacitance between A and B is

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QUESTION: 10

A generator at a utility company produces 100 A of current at 4000 V. The voltage is stepped up to 240000 V by a transformer before it is sent on a high voltage transmission line. The current in transmission line is

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QUESTION: 11

In a pure inductive circuit with a.c. source, the current lags behind e.m.f. by

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QUESTION: 12

The number of turs of primary and secondary coils of a transformer are 5 and 10 respectively and mutual inductance of the transformer is 25 H. Now, number of turns in primary and secondary are made 10 and 5 respectuvely. Mutual inductance of transformer will be

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QUESTION: 13

A coil of inductances 300mH and resistance 2 Ω is connected to a source of voltage 2V. The current reaches half of its steady state value in

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QUESTION: 14

The waves which can not travel in vacuum are

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QUESTION: 15

A charge q is located at the centre of a cube. The electric flux through any face is

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QUESTION: 16

When a dielectric material is kept in between the plates of a condenser, its capacity

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QUESTION: 17

A long spring is stretched by 2 cm, its potential energy is U. If the spring is stretched by 10 cm, the potential energy stored in it will be

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QUESTION: 18

If g is the acceleration due to gravity on the earth's surface, the gain in the potential energy of an object of mass m raised from the surface of earth to a height equal to the radius of the earth R, is

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QUESTION: 19

The cause of Fraunhoffer lines is

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QUESTION: 20

A 10 microfarad capacitor is charged to 500 V and then its plates are joined together through a resistance of 10 ohm. the heat produced in the resistance is

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QUESTION: 21

A frog can be levitated in magnetic field produced by a current in a vertical solenoid placed below the frog. This is possible because the body of the frog behaves as

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QUESTION: 22

The effective length of a magnet is 31.4 cm, and its pole strength is 0.5 A-m. If it is bent in the form of a semicircle,then its new magnetic moment will be

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QUESTION: 23

A wire of length L and radius a rigidly fixed at one end. On stretching the other end of the wire with a force F, the increase in it length is l. If another wire of same material but of length 2L and radius 2a is stretched with a force 2F, the increase in its length will be

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QUESTION: 24

A jet plane flies in the air because

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QUESTION: 25

A cyclotron can not accelerate

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QUESTION: 26

In a simple harmonic motion displacement is half of its amplitude, what will be the ratio of K.E. and P.E.

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QUESTION: 27

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): A particle of mass m collides with another stationary particle of mass M. If the particle m stops just after the collision, the coefficient of restitution of collisions is equal to 1.
Reason(R): Momentum of system just before and after the collision remains constant.

Solution:
QUESTION: 28

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Size of U235 is not essential for the phenomenon of nuclear fission.
Reason(R): Chain reaction takes place in nuclear fission.

Solution:
QUESTION: 29

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Magnetic induction inside a straight solenoid of finite length is μ₀ni.
Reason(R):

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QUESTION: 30

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): When net force is perpendicular to direction of velocity, it just changes its direction and not magnitude.
Reason (R): This results in uniform circular motion.

Solution:
QUESTION: 31

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Vapour is condensed in the form of drops on ions, not on air molecules.
Reason(R): Molecules are very small is size.

Solution:
QUESTION: 32

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Different ionising particles produce different tracks in Wilson Cloud chamber.
Reason(R): Penetration ranges are different.

Solution:
QUESTION: 33

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): When a body is rolling, its kinetic energy is equal to the sum of translational K.E. of all the particles.
Reason(R): Rolling is the combined motion of translatory as well as rotatory.

Solution:
QUESTION: 34

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Least count of all screw based instruments is same.
Reason(R): Least count for all screw based instruments are found using the ratio pitch per division of circular scale.

Solution:
QUESTION: 35

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Kirchoff's loop law represents conservation of energy.
Reason(R): If the sum of potential changes around a closed loop is not zero, unlimited energy could be gained by repeatedly carrying a charge around a loop.

Solution:
QUESTION: 36

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): An open tube having a fundamental frequency v generates the same frequency when half immersed in a dense liquid.
Reason(R): On immersing the tube in a liquid, the open tube behaves as a closed pipe.

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QUESTION: 37

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): A larger dry cell has higher emf.
Reason(R): The emf of a dry cell is proportional to its size.

Solution:
QUESTION: 38

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): In Thomson's method of determining e.m , the electric and magnetic fields are kept parallel to each other.
Reason(R): So that the electric and magnetic forces on the electron will be in the same plane.

Solution:
QUESTION: 39

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Pressure in a bubble (σ) in an atmosphere of pressure P0 is P0 + 4σr where r is the radius.
Reason(R): 4σ /r is the excess pressure due to two surfaces exposed to the atmosphere.

Solution:
QUESTION: 40

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Impulsive forces are large in magnitude.
Reason(R): When impulsive force are involved the time is usually very small.

Solution:
QUESTION: 41

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): For stable equilibrium, Force has to be zero and potential energy should be minimum.
Reason(R): For equilibrium, it is not necessary that the force is not zero.

Solution:
QUESTION: 42

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): For propagation of electromagneticn waves medium is necessary
Reason(R): Electromagnetic waves are transverse waves.

Solution:
QUESTION: 43

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): For pair production, energy of γ ray is greater than 1.02 MeV.
Reason(R): In pair production, energy is converted into mass.

Solution:
QUESTION: 44

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): If a projectile explodes in air in different parts, the path of centre of mass remains unchanged.
Reason(R): During the explosion no external force acts on the C.O.M.

Solution:
QUESTION: 45

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Radio waves are not electomagnetic waves.
Reason(R): Basic source of electromagnetic wave is an accelerated charge .

Solution:
QUESTION: 46

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Due to opposition offered by self-inductance, work is done by external agent in establishing current in circuit. This work done is stored as potential energy.
Reason(R): Self-inductance of a coil depends on the geometry of coils and medium.

Solution:
QUESTION: 47

A motor boat is travelling with a speed of 3.0 m/sec. If the force on it due to a water flow is 500 N, the power of the boat is

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QUESTION: 48

The equation of motion of a projectile are given by x = 36 t metre and 2y = 90 t - 9.8 t2 metre. The angle of projection is

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QUESTION: 49

Light propagates rectilinearly because of its

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QUESTION: 50

A doctor advises a patient to use spectacles with a convex lens of focal length 40 cm in contact with a concave lens of focal length 25 cm. What is the power of the combination ?

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QUESTION: 51

Which of the following when added as an impurity into the silicon produces n-type semiconductor

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QUESTION: 52

With rise in temperature, the specific resistance of semiconductors

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QUESTION: 53

A ray of light is incident on a surface of glass slab at an angle 45º. If the lateral shift produced per unit thickness is 13 m, the angle of refraction produced is

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QUESTION: 54

Volt/metre is the unit of

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QUESTION: 55

Three bulbs of 40 W, 60 W and 100 W are arranged in series with 220 V. Which bulb has minimum resistance

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QUESTION: 56

The number of significant figures in 3400 is

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QUESTION: 57

A wavefront is an imaginary surface where

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QUESTION: 58

Two waves of same frequency, but of amplitudes in the ratio 1:3 are superimposed. The ratio of maximum to minimum intensity is

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QUESTION: 59

Who was the first to demonstrate the phenomenon of interference of light?

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QUESTION: 60

A body moves a distance of 10 m along a straight line under the action of a force of 5N. If the work done is 25 joules, the angle which the force makes with the direction of motion of the body is

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QUESTION: 61

Alcohols reacts with Grignard reagent to form

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QUESTION: 62

Electrophilic reagents are

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QUESTION: 63

Which of the following is not a nucleophile?

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QUESTION: 64

If toluene is treated with chlorine in the presence of HCl then which of the following is formed?

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QUESTION: 65

Benzene reacts with CH₃COCl in the presence of AlCl₃ to give

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QUESTION: 66

In graphite, the electrons are

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QUESTION: 67

The treatment of benzene with iso-butene in the presence of sulphuric acid gives

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QUESTION: 68

Pairs of species having identical shapes for molecules is

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QUESTION: 69

Which of the following gas changes lime water in milky colour?

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QUESTION: 70

The decomposition of a substance follows first order kinetics. Its concentration is reduced to 1/8th of its initial value in 24 minutes. The rate constant of the decomposition process is

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QUESTION: 71

Which of these does not influence the rate of reaction?

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QUESTION: 72

An endothermic reaction is one in which

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QUESTION: 73

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): All monosaccharides are sweet.
Reason(R): All monosaccharides have the general formula C6H12O6.

Solution:
QUESTION: 74

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Sodium ions are discharged in preference to H⁺ ions at mercury cathode.
Reason(R): The nature of cathode can affect the order of discharge of cation.

Solution:
QUESTION: 75

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Orlon cannot be used as synthetic fibre.
Reason(R): The monomer of orlon is vinyl chloride.

Solution:
QUESTION: 76

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Alkyl benzene is not prepared by friedel craft alkylation of benzene.
Reason(R): Alkyl halides are less reactive than acyl halides.

Solution:

Due to + I-effect of the alkyl group, electron density increases in alkylbenzene relative to benzene and hence further substitution occurs to form a poly alkyl substituted benzene

QUESTION: 77

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Borazine is called inorganic benzene.
Reason(R): Borazine has structural similarity with benzene.

Solution:
QUESTION: 78

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): HCl diffuses faster than ammonia.
Reason(R): Rate of diffusion of a gas is inversely proportional to the square root of its density.

Solution:
QUESTION: 79

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Ionic solids conduct electricity in solid state.
Reason(R): They are made up of cations and anions.

Solution:
QUESTION: 80

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Enzymes increase the rate of a reaction.
Reason(R): Enzyme action is inhibited by certain organic molecules called inhibitors.

Solution:
QUESTION: 81

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Primary cells or batteries can be recharged.
Reason(R): The electrodes and electrolytes used in primary cells cannot be restored to their original state by an external potential.

Solution:
QUESTION: 82

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): We can use any hydroxide for the precipitation of group III cations.
Reason(R): In group III, Al3⁺, Fe3⁺ and Cr3⁺ are precipitated as hydroxides.

Solution:
QUESTION: 83

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Decarboxylation of higher fatty acids by sodalime is not a useful method of preparation of alkanes.
Reason(R): Mixture of hydrocarbon is obtained, which is difficult to be separated.

Solution:
QUESTION: 84

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Electron affinity of N is more than that of P.
Reason(R): Nitrogen is smaller than P.

Solution:

Electron affinity of N is less than that of P, because the added electrons will be accomodated to smaller sizes 2p-subshell, which already housing one electron.
This results in inter-electronic repulsions and lowering of EA

QUESTION: 85

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Anti ferromagnetic substances possess zero magnetic moment.
Reason(R): MnO is an anti-ferromagnetic substance.

Solution:
QUESTION: 86

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Mercuric chloride is known as corrosive sublimate.
Reason(R): Mercuric chloride is extremely poisonous substance.

Solution:
QUESTION: 87

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): H⁺ ion has a very high polarising power.
Reason(R): Size of H⁺ ion is very small.

Solution:
QUESTION: 88

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): A colloid gets coagulated by addition of an electrolyte.
Reason(R): The rate of coagulation depends on the magnitude and sign of the charge of the coagulant ion.

Solution:
QUESTION: 89

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A):Alkenes are more reactive than alkanes.
Reason(R):Alkenes possess π bonds.

Solution:
QUESTION: 90

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Oils contain higher proportion of glycerides of saturated fatty acids.
Reason(R): Oils contain a higher percentage of olein.

Solution:
QUESTION: 91

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Na₂CO₃ does not affect the pH of pure water on dissociation.
Reason(R): Salt of strong acid and strong base do not undergo hydrolysis.

Solution:
QUESTION: 92

If equivalent conductance of 1 M benzoic acid is 12.8 ohm⁻1 cm2 and if the conductance of benzoate ion and H⁺ ion are 42 and 288.42 ohm⁻1 respectively.Its degree of dissociation is

Solution:
QUESTION: 93

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason (R) just below it. Read the Statements carefully and mark the correct answer-
Assertion(A): Hydrogen resembles halogens.
Reason(R): It has high ionisation energy but still form H⁺ ion.

Solution:
QUESTION: 94

The electrolysis of aqueous NaCl produces at cathode and anode respectively

Solution:
QUESTION: 95

If the density of oxygen is 1.43 g-L⁻1 at N.T.P., then its density at 17ºC and 800 mm of Hg is

Solution:
QUESTION: 96

Which of the following statements is incorrect?

Solution:
QUESTION: 97

Which of the following has lowest melting point?

Solution:
QUESTION: 98

What happens when few drops of H₂SO₄ are added to water?

Solution:
QUESTION: 99

Which is the lightest gas ?

Solution:
QUESTION: 100

In organic reactions, sodium in liquid ammonia is used as .........

Solution:
QUESTION: 101

Which of the following is a false statement?

Solution:
QUESTION: 102

What is X in the following reaction? MgCl₂ + H₂O → X + 2HCl

Solution:
QUESTION: 103

A solution of NH₄Cl is

Solution:
QUESTION: 104

Buffer solution can be obtained by mixing aqueous solution of

Solution:
QUESTION: 105

To suppress the dissociation of acetric acid, the compound to be added to it is

Solution:
QUESTION: 106

Which of the following reactant in the presence of AlCl₃ gives acetophenone?

Solution:
QUESTION: 107

Acetone is easily oxidising with

Solution:
QUESTION: 108

Most stable alkene is :

Solution:
QUESTION: 109

Following step is : CH3CH3+Cl→CH3CH2Cl+HCl?

Solution:
QUESTION: 110

Which of the following is the example of SN2 reaction?

Solution:
QUESTION: 111

Which type of glass has a property to cut off ultra-violet rays?

Solution:
QUESTION: 112

Which is not the resonance structure of aniline?

Solution:
QUESTION: 113

The radius of an atom of an element is 500 pm, if it crystallizes as a face-centred cubic lattice, then the edge length of the unit cell is

Solution:
QUESTION: 114

Quartz is a crystalline variety of

Solution:
QUESTION: 115

On dissolving 1 mole of each of the following acids in 1 litre water, the acid does not give a solution of strength 1 N is

Solution:
QUESTION: 116

What is the volume (in ml) of 0.1 M potassium permanganate solution required to completely oxidize 100ml of 0.5 M ferrous sulphate solution in acid medium?

Solution:
QUESTION: 117

Which of the following 0.10 m aqueous solution will have the lowest freezing point?

Solution:
QUESTION: 118

Which one of the following gases contains the least number of molecules (Atomic wights of P = 31, C = 12, Cl = 35.5, H = 1, N = 14)

Solution:

Number of molecules = No. of moles x 6.023 x 1023
= ( weight of substance GMW of the substance ) x 6.023x 1023
Laughing gas - Nitrous oxide (N2O)
No. of molecules = 4 43 x 6.023x 1023
(GMW of N2O = (14 x2) + 15 = 43)
= 24.092 x 10 23 43
= 0.560 x 1023
Phosphine = (PH3)
No. of molecules = 3 34 x 6.023 x 1023
(GMW of PH3 = (31 + (1 x 3) = 34)
= 18.069 x 10 23 34
= 0.531 x 1023
Marsh gas = (CH4)
No. of molecules = 2 16 x 6.023 x 1023
(GMW of CH4 = (12 + (1 x 4) = 16)
= 12.046 x 10 23 16
= 0.752 x 1023
Phosgene = (COCl2)
No. of molecules = 10 97 x 6.023 x1023
(GMW of COCl2 = (12 + 15 + (35 x 2)) = 97)
= 60.23 x 10 23 97
= 0.62 x 1023
The least number of molecules is in 3 gram of phosphine

QUESTION: 119

Stereoisomers have different :

Solution:
QUESTION: 120

The reason for the stability of Gd3⁺ ion is

Solution:
QUESTION: 121

Starting from outside, the layer present in intestinal wall, are

Solution:
QUESTION: 122

Silk is obtained from

Solution:
QUESTION: 123

Flight muscles of bird are attached to

Solution:
QUESTION: 124

In the following question, a statement of Assertion(A) is given followed by a corresponding statement of Reason(R). Read the statements carefully, and mark the correct answer.
Assertion(A): Persons suffering from haemophilia fail to produce blood clotting factor VIII.
Reason(R): Prothrombin producing platelets in such persons are found in very low concentration.

Solution:

Haemophilia is a blood disorder where the blood does not clot normally. Haemophilia A is the most common form, caused by a deficiency of blood clotting factor VIII. Haemophilia B is due to a deficiency of blood clotting factor IX. Haemophilia is an hereditary disorder. In almost all cases, it is males that suffer the condition, although it is passed on by both females and males carrying the gene. Queen Victoria was a carrier of haemophilia A. It is also known as classical haemiophilia and factor VIII deficiency haemophilia, B is also known as Factor IX haemophilia, and Christmas disease after the first patient diagnosed with it. Prophrombin producing platelets in such persons are not found in very low concentraion.

QUESTION: 125

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason(R) just below it.Read the Statement carefully and mark the correct answer-
Assertion(A): Chlorenchyma naver photosynthesises.
reason (R): Collenchyma gives a tensible strength to the organs.

Solution:
QUESTION: 126

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason(R) just below it. Read the Statement carefully and mark the correct answer-
Assertion(A): Carotene is a type of carotenoid.
Reason (R): Carotene is a precursor of vitamin A.

Solution:
QUESTION: 127

In the following question, a statement of Assertion(A) is given followed by a corresponding statement of Reason(R). Read the statements carefully, and mark the correct answer.
Assertion(A): Co-enzyme is a non-protein group without which certain enzymes are inactive or incomplete.
Reason(R): Co-enzymes not only provide a point of attachment of the chemical group being transformed but also influence the properties of the group.

Solution:

Activity of enzymes is dependant on the structure of proteins, addition of nonprotein and cofactor. The cofactor may be either a metal ion or a complex organic molecule called a coenzyme usually function as intermediary carriers of electrons or of specific atoms or functional groups that are transferred in the overall enzymatic reaction.

QUESTION: 128

In the following question, a statement of Assertion(A) is given followed by a corresponding statement of Reason(R). Read the statements carefully, and mark the correct answer.
Assertion(A): Plasma membrane is excceedingly thin and not visible as a separate layer.
Reason(R): It appears merely as a surface layer of cytoplasm.

Solution:

Plasma membrane is required by all living organisms. Plasma membrane can not be seen under light microscope as separate layer. It has no cell cement and thus, it is very thin. The membrane is responsible for the relationship of a cell with the outside world.

QUESTION: 129

In the following question, a statement of Assertion(A) is given followed by a corresponding statement of Reason(R). Read the statements carefully, and mark the correct answer.
Assertion(A): Agricultural output increased several tims after introduction of DDT.
Reason(R): DDT was the first insecticide used on a wide scale.

Solution:

DDT or dichloro-diphenyl trichloroethane was the first important synthetic pesticide discovered in 1939 by a Swiss chemist Paul Muller. It was toxic to wide range of insect pests yet appeared to have low toxicity to mammals. It was persistent which means it do not break down rapidly in the environment, so that it did not have to be reapplied often. DDT was so effective at killing pests and thus boosting crops yield and was so inexpensive to make that its use quickly spread over the globe. Farmers used more and more DDT throughout the 1950 and 1960 to get an increased yield of crop.

QUESTION: 130

In the following question, a statement of Assertion(A) is given followed by a corresponding statement of Reason(R). Read the statements carefully, and mark the correct answer.
Assertion(A): Leguminous plants are best preferred for rotation of crops.
Reason(R): They have root nodules which have nitrogen fixing bacterium Clostridium.

Solution:

Usually non-leguminous crops like wheat, rice, millets etc. are rotated with leguminous crops gram , pea, pulses, beans, groundnut, alfalfa, clover, etc. Leguminous plants bear nodulated roots. The root nodules contain nitrogen fixing bacteria of the genus Rhizobium. The bacteria convert molecular nitrogen into salts of nitrogen. The later enrich the leguminous crop as well as soil. Therefore, crop rotation maintains the nitrogen fertility of the soil when legume crop is rotated with others.

QUESTION: 131

In the following question, a statement of Assertion(A) is given followed by a corresponding statement of Reason(R). Read the statements carefully, and mark the correct answer.
Assertion(A): Specialization of cells is advantageous for the organism.
Reason(R): It increases the operational efficiency of an organism.

Solution:

It is advantageous for the organism that the cells are specialised into tissues, organs and organ systems. This specialisation increases the operational efficiency through division of labour which avoids duplication of work.

QUESTION: 132

In the following question, a statement of Assertion(A) is given followed by a corresponding statement of Reason(R). Read the statements carefully, and mark the correct answer.
Assertion(A): Chlorofluorocarbons are responsible for ozone depletion.
Reason(R): Ozone level decrease by as much as 67% every year.

Solution:

A slight thinning of ozone layer occurs naturally for a few months every year over Antarctica. It decreases by 67% every year.The primary chemicals responsible for ozone depletion are a group of chlorine containing compounds called Chloroflurocarbons (CFCs), used as coolants in air aonditioners and refrigerators and propellants for aerosol cans and form blowing agents for insulation and packaging and also as solvents. Besides halons, methyl bromide, methyl chloroform, carbon tetrachloride and nitorus oxide are also responsible for O3 loss. After their release into troposphere, CFCs and other chlorine containing compounds go to stratosphere where these are broken down by UV- radiations releasing chlorine. Similarly bromine is released by breakdown of halons and methly bromide. The sunlight catalyses the chemical reactions by which chlorine or bromine break O3 molecules and convert them into O2 molecules. This chemical reaction does not change chlorine or bromine and thus single chlorine or bromine atom can breakdown many thousands of O3 molecules.

QUESTION: 133

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason(R) just below it.Read the Statement carefully and mark the correct answer-
Assertion(A): Protostele is the simplest type of stele.
Reason (R): Siphonostele has pith in the centre.

Solution:
QUESTION: 134

In the following question, a statement of Assertion(A) is given followed by a corresponding statement of Reason(R). Read the statements carefully, and mark the correct answer.
Assertion(A): Vernalization is acceleration of subsequent flowering by low temperature treatment.
Reason(R): Site of vernalization is apical meristem.

Solution:

Vernalization is the low temperature treatment given to water soaked seeds, slightly germinated seeds oe seedlings to hasten the flowering ofplants that will develop from them.T.D. Lysenko in 1928 for the first time used the term vernalization foe a low temperature promotion of flowering in plants.
The site of vernalization in most of the plants is apical meristematic cells in the bud.

QUESTION: 135

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason(R) just below it. Read the Statement carefully and mark the correct answer-
Assertion(A): Transpiration is maximum in succulents.
Reason (R): Stomata opens during night in succulents.

Solution:
QUESTION: 136

In the following question, a statement of Assertion(A) is given followed by a corresponding statement of Reason(R). Read the statements carefully, and mark the correct answer.
Assertion(A): Aldosterone is a steroid hormone and is important in the control of sodium and potassium ion concentration in mammals.
Reason(R): It upgrades sodium ion concentration in the ECF by promoting reabsorption of sodium ions from renal tubules and excretion of postassium ions in urine.

Solution:

Aldosterone is a hormone that increases the reabsorption of sodium ions and water and the release (secretion) of potassium ions in the distal convoluted tubules of the kidneys. This increases blood volume and, therefore, increases blood pressure.
Acting on the nuclear mineralocorticoid receptors (MR) within the principal cells of the distal tubule and the collecting duct of the kidney nephron, it upregulates and activates the basolateral Na+ or K+ pumps, stimulating ATP hydrolysis leading to phosphorylation of the pump and a conformational change in the pump exposes the Na+ ions to the outside. The phosphorylated form of the pump has a low affinity for Na+ ions, hence reabsorbing sodium (Na+) ions and water into the blood, and secreting potassium (K+) ions into the urine. Aldosterone stimulates uptake of K+ into cells.Aldosterone stimulates Na+ and water reabsorption from the gut salivary and sweat glands in exchange for K+. Aldosterone stimulates H+ secretion by intercalated cells in the collecting duct, regulating plasma bicarbonate (HCO3-) levels and its acid/base balance.

QUESTION: 137

In the following question, a statement of Assertion(A) is given followed by a corresponding statement of Reason(R). Read the statements carefully, and mark the correct answer.
Assertion(A): A single strand of m-RNA is capable of forming a number of different polypeptide chains.
Reason(R): Termination codons occur in m-RNA.

Solution:

Messenger RNA (mRNA) is a molecule of RNA encoding a chemical "blueprint" for a protein product. mRNA brings instructions from the DNA for the formation of particular type of polypeptide. The instructions are present in the base sequence of its nucleotides. mRNA has methylated region at the 5'terminus. It functions as a cap for attachment with ribosome. Cap is followed by an initiation codon (AUG) either immediately or after a small noncoding region. An mRNA may specify only a singled monocistronic while the latter is known as polycistronic.
Three of the 64 codons are UAG (amber), UAA (ochre) and UGA (opal or umber), they bring about termination of polypeptide chain synthesis and are called termination codons or stop codons.

QUESTION: 138

In the following question, a statement of Assertion(A) is given followed by a corresponding statement of Reason(R). Read the statements carefully, and mark the correct answer.
Assertion(A): Living organisms are regarded as closed systems.
Reason(R): Energy of living organisms cannot be lost or gained from the environment.

Solution:

Living organisms are regarded as open system as they can loose or gain the mass oe eneregy from the surrounding environment. All living organisms restore their lost energy from the sunlight or indirectly from the food material.

QUESTION: 139

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason(R) just below it. Read the Statement carefully and mark the correct answer-
Assertion(A): Ants generally disperse the fruits and seeds having oil bodies.
Reason (R): They feed on the oily substances.

Solution:
QUESTION: 140

In the following question, a statement of Assertion(A) is given followed by a corresponding statement of Reason(R). Read the statements carefully, and mark the correct answer.
Assertion(A): Thiamine deficiency results in beri-beri causing paralysis.
Reason(R): People eating raw fish may also suffer from paralysis due to the deficiency of vitamin B1. Cooked fish has no such effect.

Solution:

Thiamine deficiency results in Beri-beri disease causing paralysis.
Thiamine or vitamin B1 is an antineuritic vitamin. Beri-beri is characterized by loss of appetite and weight, retrded growth, degeneration of nerves and muscle atrophy, thus in acute cases leads to paralysis.
Raw freshwater fish and shellfish contain chemicals that destroy thiamine. Eating a lot of raw fish or shellfish can contribute to thiamine deficiency. But cooked fish and seafood are OK. They don't have any affect on thiamine, because cooking destroys the chemicals that harm thiamine.

QUESTION: 141

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason(R) just below it. Read the Statement carefully and mark the correct answer-
Assertion(A): Smooth muscle fibres do not appear to be striated.
Reason (R): This is due to regular alternate arrangement of thick and thin filaments in smooth muscle fibre.

Solution:
QUESTION: 142

In the following question, a statement of Assertion(A) is given followed by a corresponding statement of Reason(R). Read the statements carefully, and mark the correct answer.
Assertion(A): Chromosomal aberrations are caused by a break in the chromosome or its chromatid.
Reason(R): Duplication, deficiency, transversion and translocations are the result of chromosomal aberrations.

Solution:

Chromosomal aberrations are disruptions in the normal chromosomal content of a cell, and are a major cause of genetic conditions in humans, such as Down syndrome. Strucural changes are caused by break in the chromosome or chromatid and can be of following types: (i) deficiency, involves loss of a part of chromosome, (ii) duplication, involves addition of a part of chromosome, (iii) inversion involves a reverse order of the genes in a part of chromosome and (iv) translocation, involves exchange of segments between non-homologous chromosomes.

QUESTION: 143

In the following question, a Statement of Assertion (A) is given followed by a corresponding Reason(R) just below it. Read the Statement carefully and mark the correct answer-
Assertion(A): Wilting occurs due to loss in turgidity.
Reason (R): Turgor pressure checks the excessive entry of water into cells.

Solution:
QUESTION: 144

Which of the following is a reducing sugar?

Solution:
QUESTION: 145

What is true ?

Solution:
QUESTION: 146

Alcoholic fermentation takes place in the presence of

Solution:
QUESTION: 147

Characters are transferred from parents to offspring through :

Solution:
QUESTION: 148

IPM (Intergrated Pest Management) involves

Solution:
QUESTION: 149

Dentition in mammal is

Solution:
QUESTION: 150

Lint and fuzz are characteristics of the fibres of

Solution:
QUESTION: 151

In a cross 45 tall and 14 dwarf plants were obtained. Genotype of parents was

Solution:
QUESTION: 152

Which of the following came after Dryopithecus during the evolution of man?

Solution:
QUESTION: 153

A genetically diseased male marries a normal female producing three diseased girls and five normal sons. It would be a

Solution:
QUESTION: 154

Central dogma of modern biology is

Solution:
QUESTION: 155

DNA replication requires

Solution:
QUESTION: 156

The cheapest high energy fruit crop of India is

Solution:
QUESTION: 157

Gamma-globulins are synthesised in

Solution:
QUESTION: 158

Cyathium and hypanthodium types of inflorescence are similar in having

Solution:
QUESTION: 159

Cyclosporine is useful in

Solution:
QUESTION: 160

Which of the following is correctly matched

Solution:
QUESTION: 161

Edward Jenner is called father of

Solution:
QUESTION: 162

Azolla is used as biofertilizer, because it has

Solution:
QUESTION: 163

True nucleus and mitochondria are absent in

Solution:
QUESTION: 164

Vermis is

Solution:
QUESTION: 165

Clay and organic matter of the soil have negative charges. They attract positively charged ions like

Solution:
QUESTION: 166

The hypothesis that all photosynthetic organisms require a source of hydrogen was given by

Solution:
QUESTION: 167

Both respiration and photosynthesis require

Solution:
QUESTION: 168

Yogurt is formed by

Solution:
QUESTION: 169

Bicollateral bundles occur in the stem of

Solution:
QUESTION: 170

DDT has been a major pollutant because it

Solution:
QUESTION: 171

Early in embryonic development, the morula forms a hollow-ball stage; shortly thereafter, some cells migrate to the interior of this ball and become the

Solution:
QUESTION: 172

Companion cells are associated with

Solution:
QUESTION: 173

In angiosperms the functional megaspore of linear tetrad is the

Solution:
QUESTION: 174

Amino acid present in histones are

Solution:
QUESTION: 175

The function of the endometrium is to

Solution:
QUESTION: 176

Alveoli would not be characterised as

Solution:
QUESTION: 177

Which are involved in muscle contraction ?

Solution:
QUESTION: 178

m-RNA is made up of :

Solution:
QUESTION: 179

Unit of natural selection is

Solution:
QUESTION: 180

Pickup the example of homeostasis amongst the following

Solution: