NEET 2015 Solved Question Paper


180 Questions MCQ Test NEET Mock Test Series 2020 & Past Year Papers | NEET 2015 Solved Question Paper


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This mock test of NEET 2015 Solved Question Paper for NEET helps you for every NEET entrance exam. This contains 180 Multiple Choice Questions for NEET NEET 2015 Solved Question Paper (mcq) to study with solutions a complete question bank. The solved questions answers in this NEET 2015 Solved Question Paper quiz give you a good mix of easy questions and tough questions. NEET students definitely take this NEET 2015 Solved Question Paper exercise for a better result in the exam. You can find other NEET 2015 Solved Question Paper extra questions, long questions & short questions for NEET on EduRev as well by searching above.
QUESTION: 1

Q. No- 1 - 90 carry 4 marks each and 1 mark is deducted for every wrong answer.

Q.

 Leaves become modified into spines in :

Solution:
in opuntia plant leaves modified into spines to reduce rate of transpiration...
QUESTION: 2

Vertical distribution of different species occupying different levels in a biotic community is known as :

Solution:

Stratification is the occurrence of vertical zonation in the ecosystem & indicates the presence of favorable environmental conditions, for e.g., trees occupy top vertical strata or layer of a forest, shrubs the second. Herbs & grasses occupy the bottom layers. It is absent or poor where environmental conditions are unfavorable, e.g., desert ecosystems have very few trees & shrubs.

QUESTION: 3

Transpiration and root pressure cause water to rise in plants by :

Solution: Transpiration causes water to rise in plants by pulling through xylem elements.Root pressure causes water to rise in plants by pushing water in xylem components.So, the rise of water in plants is done by pulling and pushing via transpiration and root pressure respectively.
QUESTION: 4

Gene regulation governing lactose operon of E.coli that involves the lac I gene product is :

Solution:

Lac I gene produces an inhibitor or repressor and negative regulation of lac operon is induced. The repressor binds to the operator gene and stops its working. Repressor is meant to block the operator gene so that structural genes are unable to form mRNA thus stopping the transcription of genes.

QUESTION: 5

High value of BOD (Biochemical Oxygen Demand) indicates that :

Solution:
QUESTION: 6

Which one of the following matches is correct?

 

Solution:
QUESTION: 7

Which of these is not an important component of initiation of parturition in humans?

Solution:
QUESTION: 8

A chemical signal that has both endocrine and neural roles is

Solution:
QUESTION: 9

Match each disease with its correct type of vaccine :

Solution:
QUESTION: 10

Nuclear envelope is a derivative of :

Solution:

The perinuclear space present between two membranes of nuclear envelope runs continuous with channels of the ER aiding in shrinkage or expansion of envelope. Nuclear envelope is a derivative of rough endoplasmic reticulum.

QUESTION: 11

The crops engineered for glyphosate are resistant/tolerant to:

Solution:
QUESTION: 12

Vascular bundles in monocotyledons are considered closed because :

Solution:
QUESTION: 13

Read the following five statements (A to E) and select the option with all correct statements :

(A) Mosses and Lichens are the first organisms to colonise a bare rock.
(B) Selaginella is a homosporous pteridophyte.
(C) Coralloid roots in Cycas have VAM.
(D) Main plant body in bryophytes is gametophytic, whereas in pteridophytes it is sporophytic.
(E) In gymnosperms, male and female gametophytes are present within sporangia located on sporophyte

Solution:
QUESTION: 14

True nucleus is absent in :

Solution:
QUESTION: 15

Which one of the following statements in not true?

Solution:
QUESTION: 16

Removal of proximal convoluted tubule from the nephron will result in :

Solution:
QUESTION: 17

A gymnast is able to balance his body upside down even in the total darkness because of :

Solution: Vestibular apparatus is the sensory system that provides the leading contribution to the sense of balance and spatial orientation for the purpose of coordinating movement with balance.
QUESTION: 18

The hilum is a scar on the :

Solution: In botany, a hilum (pronounced /ˈhaɪləm/) is a scar or mark left on a seed coat by the former attachment to the ovary wall or to the funiculus (which in turn attaches to the ovary wall). On a bean seed, the hilum is called the "eye".
QUESTION: 19

Which one of the following is correct?

Solution:
QUESTION: 20

The guts of cow and buffalo possess :

Solution:
QUESTION: 21

Which one of the following may require pollinators, but is genetically similar to autogamy?

Solution:
QUESTION: 22

In sea urchin DNA, which is double stranded, 17 % of the bases were shown to be cytosine. The percentages of the other three bases expected to be present in this DNA are :

Solution:
QUESTION: 23

Capacitation refers to changes in the

Solution:
QUESTION: 24

Which of the following had the smallest brain capacity?

Solution:
QUESTION: 25

Which of the following viruses is not transferred through semen of an infected male?

Solution:
QUESTION: 26

A major characteristic of the monocot root is the presence of :

Solution: In monocots there is no cambium in between xylem and phloem. so secondary growth is absent.
QUESTION: 27

Blood pressure in the mammalian aorta is maximum during:

Solution:
QUESTION: 28

In Bt cotton, the Bt toxin present in plant tissue as pro?toxin is converted into active toxin due to :

Solution:
QUESTION: 29

In an ecosystem the rate of production of organic matter during photosynthesis is termed as :

Solution:
QUESTION: 30

In a ring girdled plant :

Solution: In a ring girdled plant, the root dies first. A ring of bark is cut from the stem. It also removes phloem. Nutrients collect above the ring where the bark also swells up and may give rise to adventitious roots.
QUESTION: 31

Erythropoiesis starts in :

Solution:
QUESTION: 32

Keel is the characteristics feature of flower of :

Solution: Indigofera as it belongs to fabaceae.
QUESTION: 33

In which of the following gametophyte is not independent free living?

Solution:
Pinus
Gametophyte is phase of life cycle in which the gametes, i.e. egg and sperm are produced. In bryophytes (Funaria and Marchantia) fertilisation is dependent on water for the transfer of sperm to the egg. The gametophyte are fetilized outside the body. Therefore, they have independent free-living gametophyte.

In this respect Pteridophyte are similar to bryophytes i.e they still have free-living gametophytes. Pinaceae (Pinus) has well developed gametophyte in which sperm cells are fertilised with egg cell within the ovule. Hence, pinus is the correct option.
QUESTION: 34

The structures that are formed by stacking of organized flattened membranous sacs in the chloroplasts are:

Solution:
QUESTION: 35

Which of the following does not favour the formation of large quantities of dilute urine ?

Solution: Renin which is secreted by juxtaglomerular kidney cell which is known as angiotensin . it controls blood pressure and mediates the volume of fluid in body.
QUESTION: 36

DNA is not present in:

Solution:
QUESTION: 37

Which of the following are the important flora rewards to the animal pollinators?

Solution:
QUESTION: 38

Which of the following represents the correct combination without any exception?

Solution:
QUESTION: 39

Alleles are:

Solution:
QUESTION: 40

Hysterectomy is surgical removal of:

Solution:
QUESTION: 41

The UN Conference of Parties on climate change in the year 2011 was held in :

Solution:
QUESTION: 42

HIV that causes AIDS, first starts destroying :

Solution:
QUESTION: 43

Which one of the following statements is wrong?

Solution:
QUESTION: 44

Cryopreservation of gametes of threatened species in viable and fertile condition can be referred to as:

Solution:
QUESTION: 45

Select the correct matching in the following pairs:

Solution:
QUESTION: 46

Secondary Succession takes place on/in :

Solution:
QUESTION: 47

Which of the following is not a sexually transmitted disease ?

Solution:
QUESTION: 48

The movement of a gene from one linkage group to another is called:

Solution:
QUESTION: 49

The following graph depicts changes in two populations (A and B) of herbivores in a grassy field. A possible reason for these changes is that:

Solution:
QUESTION: 50

Typical growth curve in plants is :

Solution:
QUESTION: 51

Which one gives the most valid and recent explanation for stomatal movements ?

Solution:
QUESTION: 52

Cytochromes are found in:

Solution:
QUESTION: 53

Rachel Carson's famous book "Silent Spring" is related to:

Solution:
QUESTION: 54

Which of the following regions of the brain is incorrectly paired with its function ?

Solution:
QUESTION: 55

Which of the following characteristics is mainly responsible for diversification of insects on land?

Solution:
QUESTION: 56

Sliding filament theory can be best explained as :

Solution:
QUESTION: 57

Which one of the following is not an inclusion body found in prokaryotes?

Solution:
QUESTION: 58

The mass of living material at a trophic level at a particular time is called :

Solution:
QUESTION: 59

Select the correct option:

Solution:
QUESTION: 60

Multiple alleles are present:

Solution:
QUESTION: 61

Which of the following is not one of the prime health risks associated with greater UV radiation through the atmosphere due to depletion of stratospheric ozone ?

Solution:
QUESTION: 62

Which is the most common mechanism of genetic variation in the population of a sexually-reproducing organism?

Solution:
QUESTION: 63

Minerals known to be required in large amounts for plant growth include:

Solution:
QUESTION: 64

Transmission tissue is characteristic feature of

Solution:
QUESTION: 65

A man with blood group =A‘ marries a woman with blood group =B‘. What are all the possible blood groups of their offsprings?

Solution:
QUESTION: 66

Which of the following statements is not correct ?

Solution:
QUESTION: 67

Perigynous flowers are found in :

Solution:
QUESTION: 68

An abnormal human baby with 'XXX' sex chromosomes was born due to:

Solution: Formation of abnormal ova in the mother during division of oocyte.
QUESTION: 69

What causes a green plant exposed to the light on only one side, to bend toward the source of light as it grows ?

Solution:
QUESTION: 70

The chromosomes in which centromere is situated close to one end are :

Solution:
QUESTION: 71

A technique of micropropagation is:

Solution:
QUESTION: 72

A somatic cell that has just completed the S phase of its cell cycle, as compared to gamete of the
same species, has:

Solution: (D) is right becz just after s phase of cell cycle the DNA content get doubled not chromosome as compared to somatic cell, But here comprison with gamet cell hence chromosome would be twice and DNA amount would be four times.
QUESTION: 73

Gastric juice of infants contains :

Solution:
QUESTION: 74

Which of the following animals is not viviparous ?

Solution:
QUESTION: 75

  is the floral formula of

Solution:
QUESTION: 76

In which of the following both pairs have correct combination?

Solution:
QUESTION: 77

Which body of the Government of India regulates GM research and safety of introducing GM organisms for public services ?

Solution:
QUESTION: 78

Which of the following endoparasites of humans does show viviparity ?

Solution:
QUESTION: 79

The terga, sterna and pleura of cockroach body are joined by:

Solution:
QUESTION: 80

Most animals are tree dwellers in a:

Solution:
QUESTION: 81

Which of the following enhances or induces fusion of protoplasts ?

Solution:
QUESTION: 82

Glenoid cavity articulates :

Solution:
QUESTION: 83

A population will not exist in Hardy?Weinberg equilibrium if :

Solution:
QUESTION: 84

Male gametes are flagellated in :

Solution:
QUESTION: 85

When you hold your breath, which of the following gas changes in blood would first lead to the urge to breathe?

Solution:
QUESTION: 86

Which of the following cells during gametogenesis is normally diploid?

Solution:
QUESTION: 87

In ginger vegetative propagation occurs through :

Solution:
QUESTION: 88

Which one of the following statements is incorrect?

Solution:
Competitive inhibitor resembles closely with the substrate and competes for the active binding site of the enzyme.
The presence of competitive inhibitor decreases the affinity of the substrate to binding site of the enzyme which results in increase of Michaelis-Menten constant (km).

Competitive inhibitor resembles closely with the substrate and competes for the active binding site of the enzyme.
The presence of competitive inhibitor decreases the affinity of the substrate to binding site of the enzyme which results in increase of Michaelis-Menten constant (km).
QUESTION: 89

The active form of Entamoeba histolytica feeds upon:

Solution: Entamoeba hostolytica feeds on erythrocytes, mucosal n submucosa of colon which leads to amoebiasis.
QUESTION: 90

How many pairs of contrasting characters in pea plants were studied by Mendel in his experiments?

Solution:
QUESTION: 91

Q. No. 91-135 carry 4 marks each and 1 mark is deducted for every wrong answer.

Q.

A radiation of energy = E’ falls normally on a perfectly reflecting surface. The momentum transferred
to the surface is (C = Velocity of light) :

Solution:

The radiation energy is given by

Initial momentum of the radiation is

The reflected momentum is

So, the change in momentum of light is

Thus, the momentum transferred to the surface is

QUESTION: 92

A ship A is moving Westwards with a speed of 10 km h-1 and a ship B 100 km South of A, is moving
Northwards with a speed of 10 km h-1. The time after which the distance between them becomes
shortest, is :

Solution:

 

QUESTION: 93

Three blocks A, B and C, of masses 4 kg, 2 kg and 1 kg respectively, are in contact on a frictionless
surface, as shown. If a force of 14 N is applied on the 4 kg block, then the contact force between A
and B is :

Solution:

a =14/7 = 2m/s2
14 - N1 = 4 x 2
N1 = 6N

QUESTION: 94

The electric field in a certain region is acting radially outward and is given by E = Ar . A charge
contained in a sphere of radius =a‘ centred at the origin of the field, will be given by :

Solution:

QUESTION: 95

A, B and C are voltmeters of resistance R, 1.5 R and 3R respectively as shown in the figure. When
some potential difference is applied between X and Y, the voltmeter readings are VA, VB and VC
respectively.
Then :

Solution:

QUESTION: 96

In a double slit experiment, the two slits are 1 mm apart and the screen is placed 1 m away. A
monochromatic light of wavelength 500 nm is used. What will be the width of each slit for obtaining
ten maxima of double slit within the central maxima of single slit pattern ?

Solution:

In a double slit experiment, the two slits are 1 mm apart.
d = 1 mm = 10-3 m.
The screen is placed at a distance D = 1 m away. Monochromatic light of wave length
λ = 500 nm = 5 x 10-7 m is used.
The distance between two successive maxima or two successive minima is

QUESTION: 97

One mole of an ideal diatomic gas undergoes a transition from A to B along a path AB as shown in
the figure,

The change in internal energy of the gas during the transition is :

Solution:

QUESTION: 98

A rod of weight W is supported by two parallel knife edges A and B and is in equilibrium in a
horizontal position. The knives are at a distance d from each other. The centre of mass of the rod is at
distance x from A. The normal reaction on A is :

Solution:

QUESTION: 99

Kepler's third law states that square of period of revolution (T) of a planet around the sun, is
proportional to third power of average distance r between sun and planet
i.e. T2 = Kr3
here K is constant.
If the masses of sun and planet are M and m respectively then as per Newton?s law of gravitation force
of attraction between them is

F= GMm/r, here G is gravitational constant

The relation between G and K is described as :

Solution:

QUESTION: 100

If in a p-n junction, a square input signal of 10 V is applied, as shown,

then the output across RL will be :

Solution:
QUESTION: 101

Two particles of masses m1, m2 move with initial velocities u1 and u2. On collision, one of the
particles get excited to higher level, after absorbing energy ε. If final velocities of particles be v1 and
v2 then we must have :

Solution:

QUESTION: 102

Which of the following figures represent the variation of particle momentum and the associated de-Broglie wavelength?

Solution:

The de-Broglie wavelength is given by

This equation is in the form of yx = c, which is the equation of a rectangular hyperbola.
The de-Broglie wavelength is given by

This equation is in the form of yx = c, which is the equation of a rectangular hyperbola.

QUESTION: 103

The approximate depth of an ocean is 2700 m. The compressibility of water is 45.4 x 10-11 Pa-1 and
density of water is 103 kg/m3. What fractional compression of water will be obtained at the bottom of
the ocean?

Solution:

QUESTION: 104

The two ends of a metal rod are maintained at temperatures 100oC and 110oC. the rate of heat flow in
the rod is found to be 4.0 J/s. If the ends are maintained at temperatures 200oC and 210oC, the rate of
heat flow will be :

Solution:

Here, ΔT1 = 110-100 = 10o C

As the rate of heat flow is directly proportional to the temperature difference and the temperature difference in both the cases is same i.e. 10o C. So, the same rate of heat will flow in the second case. 
Hence,

As the rate of heat flow is directly proportional to the temperature difference and the temperature difference in both the cases is same i.e. 10o C. So, the same rate of heat will flow in the second case. 
Hence,

QUESTION: 105

A particle of unit mass undergoes one-dimensional motion such that its velocity varies according to

v(x) = βx-2n,
where β and n are constants and x is the position of the particle. The acceleration of the particle as a
function of x, is given by :

Solution:

QUESTION: 106

The refracting angle of a prism is A, and refractive index of the material of the prism is cot (A/2). The angle of minimum deviation is :

Solution:

QUESTION: 107

A particle is executing SHM along a straight line. Its velocities at distances x1 and x2 from the mean
position are V1 and V2, respectively. Its time period is :

Solution:

QUESTION: 108

Two similar springs P and Q have spring constants KP and KQ, such that KP > KQ. They are stretched,
first by the same amount (case a), then by the same force (case b). The work done by the springs WP
and WQ are related as, in case (a) and case (b), respectively :

Solution:

QUESTION: 109

Consider 3rd orbit of He+ (Helium), using non-relativistic approach, the speed of electron in this orbit will be [given K = 9 x 109 constant, Z = 2 and h(Planck's Constant) = 6.6 x 10-34 J s]

Solution:

QUESTION: 110

A wire carrying current I has the shape as shown in the adjoining figure. Linear parts of the wire are very long and parallel to X  -axis while semicircular portion of radius R is lying in a Y-Z plane. The magnetic field at point O is.

Solution:

The magnetic fiedl in the different regions is given by

QUESTION: 111

A particle of mass m is driven by a machine that delivers a constant power k watts. If the particle
starts from rest the force on the particle at time t is :

Solution:

QUESTION: 112

The fundamental frequency of a closed organ pipe of length 20 cm is equal to the second overtone of
an organ pipe open at both the ends. The length of organ pipe open at both the ends is :

Solution:

For closed organ pipe fundamental frequency

For open organ pipe fundamental frequency

QUESTION: 113

An electron moving in a circular orbit of radius r makes n rotations per second. The magnetic field
produced at the centre has magnitude :

Solution:

QUESTION: 114

Two identical thin plano-convex glass lenses (refractive index 1.5) each having radius of curvature of
20 cm are placed with their convex surfaces in contact at the centre. The intervening space is filled
with oil of refractive index 1.7. The focal length of the combination is :

Solution:

QUESTION: 115

On observing light from three different stars P, Q and R, it was found that intensity of violet colour is maximum in the spectrum of P, the intensity of green colour is maximum in the spectrum of R and the intensity of red colour is maximum in the spectrum of Q. If TP, Tand TR​ are the respective absolute temperature of P, Q and R, then it can be concluded from the above observations that

Solution:

from wein displacement law 

The wavelength of red is maximum hence, the temperature of Q TQ​ will be least,  and wavelength of violet is minimum and the temperature of P TP​  will be highest, and temperature of green TR​ light will lie between P and Q

TP > TR > TQ

QUESTION: 116

If energy (E), velocity (V) and time (T) are chosen as the fundamental quantities, the dimensional
formula of surface tension will be :

Solution:

QUESTION: 117

A Carnot engine, having an efficiency of η = 1/10 as heat engine, is used as a refrigerator. If the work
done on the system is 10 J, the amount of energy absorbed from the reservoir at lower temperature is :

Solution:

QUESTION: 118

A mass m moves in a circle on a smooth horizontal plane with velocity v0 at a radius R0. The mass is
attached to a string which passes through a smooth hole in the plane as shown.

The tension in the string is increased gradually and finally m moves in a circle of radius R0/2. The
final value of the kinetic energy is :

Solution:

When a mass moves in a circle of radius R0 with velocity v0, its kinetic energy is given by

The tension in the string is gradually increased and the radius of the circle decreased to R0/2

When the radius of the circle is R   the tension in the string is the same as the centripetal force.

where L = mRv is the angular momentum which is conserved.
Work done in reducing the radius of the circle from R0 to R0/2 is

QUESTION: 119

For a parallel beam of monochromatic light of wavelength 'λ‘, diffraction is produced by a single slit
whose width 'a‘ is of the order of the wavelength of the light. If 'D‘ is the distance of the screen from
the slit, the width of the central maxima will be :

Solution:

For a parallel beam of monochromatic light of wavelength λ, diffraction is produced by a single slit whose width 'a' is of the order of the wavelength we have

where θ is the angle subtended by the first minima and the central maxima at the slit.

If x is the width of the central maxima, we have

where D is the distance of the screen from the slit

QUESTION: 120

A wind with speed 40 m/s blows parallel to the roof of a house. The area of the roof is
250 m2. Assuming that the pressure inside the house is atmospheric pressure, the force exerted by the
wind on the roof and the direction of the force will be :

(Pair = 1.2 kg/m3)

Solution:

QUESTION: 121

The ratio of the specific heats  in terms of degrees of freedom (n) is given by :

Solution:

This fits into the pattern    , where n is the number of the degrees of freedom

QUESTION: 122

If radius of the   nucleus is taken to be RAl, then the radius of  nucleus is nearly :

Solution:

Radius of the nucleus goes as

  where A is the atomic mass.
If RTe is the radius of the nucleus of telurium atom and RAl is the radius of the nucleus of aluminium atom we have

QUESTION: 123

Figure below shows two paths that may be taken by a gas to go from a state A to a state C.

In process AB, 400 J of heat is added to the system and in process BC, 100 J of heat is added to the
system. The heat absorbed by the system in the process AC will be :

Solution:

See figure alongside
Process AB is isochoric so no work is done.
Heat added to be system is Q = 400 J.
Q = ΔU + ΔW
where ΔU is the change in internal energy
ΔW is the work done.
Since ΔW = 0
ΔU = Q = 400 J
Change in internal energy is 400 J.
Process BC is isobaric and the work done is given by
ΔW = P(V2 -V1) = 6 x 104(4 x 10-3 - 2 x 10-3)
= 6 x 104 x 2 x 10-3 = 120 J
Heat added to be system is Q = 100 J.
Since Q = ΔU + ΔW
ΔU = Q- ΔW = (100 - 120) J = -20 J
Change in internal energy is - 20 J.

Total increase in internal energy is going from state A to state C is 400 - 20 = 380 J
Work done in process AC is the area under the curve

Area of the trapezium = 

Since Q = ΔU + ΔW
and ΔU the change in internal energy in process AC, we have
ΔU = 380 J and ΔW = 80 J
Q = ΔU + ΔU = 380 + 80 = 460 J

QUESTION: 124

A block of mass 10 kg, moving in x direction with a constant speed of 10 ms-1, is subjected to a
retarding force F = 0.1 x J/m during its travel from x = 20 m to 30 m. Its final KE will be :

Solution:

The block of mass M = 10 kg is moving in the x - direction with a speed v = 10 m/s.
Its initial kinetic energy is

It is subjected to a retarding force F = 0.1 x J/m during its travel from x = 20 m to 30 m.
Work done is given by

Final kinetic energy is, KEf = KEi + W = 500 - 25 = 475 J

QUESTION: 125

A conducting square frame of side 'a‘ and a long straight wire carrying current I are located in the
same plane as shown in the figure. The frame moves to the right with a constant velocity 'V‘. The emf
induced in the frame will be proportional to :

Solution:

See figure alongside.
Let x be the distance of the centre of the frame from the long
straight wire carrying current I.
Consider the point P at a distance y from the long straight wire
carrying current I.
Strength of magnetic induction at point P is given by

Integrating over y from y = (x - a/2) to y = (x + a/2)
We get

QUESTION: 126

Three identical spherical shells, each of mass m and radius r are placed as shown in figure. Consider
an axis XX' which is touching to two shells and passing through diameter of third shell.
Moment of inertia of the system consisting of these three spherical shells about XX' axis is :

Solution:

Similarly the moment of inertia of the spherical shell C about the XX' axis is

 

QUESTION: 127

Which logic gate is represented by the following combination of logic gates ?

Solution:


Truth table

This correspond to AND gate

QUESTION: 128

A block A of mass m1 rests on a horizontal table. A lights string connected to it passes over a frictionless pulley at the edge of table and from its other end another block B of mass m2 is suspended.
The coefficient of kinetic friction between the block and the table is μk. When the block A is sliding
on the table, the tension in the string is :

Solution:

See figure alongside
Let T be the tension in the string.
Let a be the acceleration of the combination


From Equation (2) and (3) we get,

 

 

QUESTION: 129

A certain metallic surface is illuminated with monochromatic light of wavelength,λ. The stopping potential for photo-electric current for this light is 3V0. If the same surface is illuminated with light of wavelength 2 λ, the stopping potential is V0. The threshold wavelength for this surface for photoelectric effect is :

Solution:

We have,

where W is the work function and (3V0) is the stopping potential when monochromatic light of
wavelength λ is used.

where V0 is the stopping potential when monochromatic light of wavelength 2λ is used. Subtracting equation (2) from equation (1)

QUESTION: 130

When two displacements represented by y1 = a sin(ωt) and y2 = b cos(ωt) are superimposed the
motion is :

Solution:

QUESTION: 131

A potentiometer wire has length 4 m and resistance 8 . The resistance that must be connected in
series with the wire and an accumulator of e.m.f. 2V, so as to get a potential gradient 1 mV per cm on
the wire is :

Solution:

Figure alongside shows
a potentiometer wire of
length L = 4m and resistance RAB = 8.
Resistance connected in series is R.
When an accumulator of emf ε = 2V is used, we have current I given by,

The resistance per unit length of the potentiometer wire is given by,

QUESTION: 132

Two spherical bodies of mass M and 5 M and radii R and 2 R are released in free space with initial
separation between their centres equal to 12 R. If they attract each other due to gravitational force
only, then the distance covered by the smaller body before collision is :

Solution:

Let centre of mass C at a distance x1 from m1 and x2 from m2

Since the masses are moving under mutual attraction the position of centre of mass remains constant.
When the masses are in contact, let x'1 and x'2 be the distance of their centres from the centre of mass.

QUESTION: 133

A resistance 'R‘ draws power 'P‘ when connected to an AC source. If an inductance is now placed in
series with the resistance, such that the impedance of the circuit becomes 'Z‘, the power drawn will be :

Solution:

A resistance R draws power P when connected to an AC source.
The magnitude of voltage of the AC source is

V2= RP

 V= 

An inductor of inductance L and reactance ωL is now placed in series with the resistance

QUESTION: 134

Across a metallic conductor of non-uniform cross section a constant potential difference is applied.
The quantity which remains constant along the conductor is :

Solution:

As the cross-sectional area of the conductor is non-uniform so current density will be different. 
As, I = JA
It is clear from Eq. (i) when an area increases the current density decreases so the number of the flow of electrons will be same and thus the current will be constant.

QUESTION: 135

A parallel plate air capacitor of capacitance C is connected to a cell of emf V and then disconnected
from it. A dielectric slab of dielectric constant K, which can just fill the air gap of the capacitor, is
now inserted in it. Which of the following is incorrect ?

Solution:

A parallel plate air capacitor of capacitance C is connected to a cell of emf V and then disconnected
from it.
The charge on the capacitor is given by
Q = CV
The energy stored in the capacitor is

 E= 1/2 CV2

When a dielectric slab of dielectric constant K is inserted in it, the charge Q is conserved. The capacitance becomes K times the original capacitance. (C'  = KC)

The voltage becomes 1/K time the original voltage

QUESTION: 136

Q. No. 136 - 180 carry 4 marks each and 1 mark is deducted for every wrong answer.

Q.

Treatment of cyclopentanone  with methyl lithium gives which of the following species ?

Solution:

QUESTION: 137

The enolic form of ethyl acetoacetate as below has :

Solution:

QUESTION: 138

Biodegradable polymer which can be produced from glycine and aminocaproic acid is :

Solution:

Nylon-2-nylon-6 or Nylon-2,6 is an alternating polyamide co-polymer of glycine and amino caproic acid.

QUESTION: 139

Consider the following compounds

Hyperconjugation occurs in :

Solution:

Hyperconjugation occurs through the H- atoms present on the carbon atom next to the double bond i.e alpha hydrogen atoms. There is no alpha -H in the structure I and II.
So, hyperconjugation occurs in structure III only ie.

QUESTION: 140

Which of the following species contain equal number of σ - and π - bonds ?

Solution:

QUESTION: 141

The correct bond order in the following species is :

Solution:

QUESTION: 142

The function of 'sodium pump' is a biological process operating in each and every cell of all animal. Which of the following biologically important ions is also a constituent of this pump?

Solution:

The sodium pump is also known as a sodium Potassium pump. This pump is important contributor to action potential produced by nerve cells. The process of moving sodium potassium ions across the cell membranes is active transport process involving the hydrolysis of ATP to provide the necessary energy.

QUESTION: 143

Which of these statements about [Co(CN)6]3- is true ?

Solution:

[Co(CN)6]3- has no unpaired electrons and will be in a low-spin configuration

QUESTION: 144

The activation energy of a reaction can be determined from the slope of which of the following graphs ?

Solution:

 

QUESTION: 145

The reaction   

Solution:

The reaction is called Williamson synthesis

QUESTION: 146

Which one is not equal to zero for an ideal solution ?

Solution:

For ideal solution, ΔSmix = 0.

QUESTION: 147

"Metals are usually not found as nitrates in their ores".
Out of the following two (a and b) reasons which is / are true for the above observation ?
(a) Metal nitrates are highly unstable
(b) Metal nitrates are highly soluble in water.

Solution:

Metal nitrates are usually not found as nitrates in their ores because they are highly soluble in water :

QUESTION: 148

An organic compound X having molecular formula C5H10O yields phenyl hydrazone and gives negative response to the iodoform test and tollen test. It produces n -pentane on reduction X could be

Solution:

Compound 'X' yields phenylhydrazone


Negative Tollens' test ⇒ ketone
Hence, the compound is 3-pentanone

QUESTION: 149

Cobalt(III) chloride forms several octahedral complexes with ammonia. Which of the following will not
give test for chloride ions with silver nitrate at 250C ?

Solution:

a) [Co(NH3)3Cl3] → [Co(NH3)2Cl3]
b) [Co(NH3)4Cl2]Cl → [Co(NH3)4Cl2]+ +Cl-
c) [Co(NH3)5Cl]Cl2  → [Co(NH3)5Cl]+ +2Cl-
d) [Co(NH3)6Cl]Cl2  → [Co(NH3)6]+ +3Cl-
In the compound (a) does not ionise so does not give test for chloride ions.

QUESTION: 150

A mixture of gases contains H2 and O2 gases in the ratio of 1 : 4 (w/w). What is the molar ratio of the two
gases in the mixture ?

Solution:

QUESTION: 151

Which of the following is the most correct electron displacement for a nucleophilic reaction to take
place ?

Solution:

Nucleophile will attack a stable carbocation (SN1 reaction).

QUESTION: 152

The electrolytic reduction of nitrobenzene in strongly acidic medium produces :

Solution:

Electrolytic reduction of nitrobenzene in weakly acidic medium gives aniline but in strongly acidic medium, it gives para-amino phenol obviously through the acid catalysed rearrangement of initially formed phenyl hydroxyl amine.

QUESTION: 153

Nitrogen dioxide and sulphur dioxide have some properties in common. Which property is shown by one
of these compounds, but not by the other ?

Solution:

NaHSO3 is used as food preservative as it produces SO2 on decomposition which checks the oxidation of food.

QUESTION: 154

Which of the following statements is correct for a reversible process in a state of equilibrium ?

Solution:

ΔG=ΔGo + 2.303 RT log K
0 = ΔGo + 2.303 RT log K
ΔGo = -2.303 RT log K

QUESTION: 155

Which of the following pairs of ions are isoelectronic and isostructural ?

Solution:

QUESTION: 156

The angular momentum of electron in 'd‘ orbital is equal to :

Solution:

Angular momentum of electron in 'd‘ orbital =

QUESTION: 157

Which of the following options represents the correct bond order ?

Solution:

QUESTION: 158

Magnetic moment 2.84 B.M. is given by : (At. Nos., Ni = 28, Ti = 22, Cr = 24, Co = 27)

Solution:

Magnetic moment =

 = 2.84 i.e., n = 2

Ni+2 i.e., 3d8 contains two unpaired electrons

QUESTION: 159

Given

The enthalpy of hydrogenation of these compounds will be in the order as :

Solution:

Higher is the stability, lower is the enthalpy of hydrogenation.
(I) is most stable due to aromatic character. Hence it has lowest enthalpy of hydrogenation.
(III) is least stable as no resonance is present. Hence, it has highest enthalpy of hydrogenation.
Thus, the decreasing order of the enthalpy of hydrogenation is III > II > I.

QUESTION: 160

A single compound of the structure

is obtainable from ozonolysis of which of the following cyclic compounds ?

Solution:

QUESTION: 161

The total number of π -bond electrons in the following structure is :

Solution:

QUESTION: 162

The Ksp of Ag2CrO4, AgCl, AgBr and AgI are respectively, 1.1 x 10-12, 1.8 x 10-10, 5.0 x 10-13,
8.3 x 10-17. Which one of the following salts will precipitate last if AgNO3 solution is added to the
solution containing equal moles of NaCl, NaBr, NaI and Na2CrO4 ?

Solution:

 

QUESTION: 163

When initial concentration of a reactant is doubled in a reaction, its half-life period is not affected. The
order of the reaction is :

Solution:

For first order reaction, half-life period is not depends upon initial concentration

QUESTION: 164

Which of the following processes does not involve oxidation of iron ?

Solution:

QUESTION: 165

Bithional is generally added to the soaps as an additive to function as a/an :

Solution:

Bithional functions as antiseptic

QUESTION: 166

In which of the following compounds, the C - Cl bond ionisation shall give most stable carbonium ion ?

Solution:

3o carbocation are more stable than benzylic carbocation

QUESTION: 167

A given metal crystallizes out with a cubic structure having edge length of 361 pm. If there are four
metal atoms in one unit cell, what is the radius of one atom ?

Solution:

It is a fcc structure

QUESTION: 168

The boiling point of 0.2 mol kg-1 solution of X in water is greater than equimolal solution of Y in
water. Which one of the following statements is true in this case ?

Solution:

Molality of solution of x = molality of solution of y = 0.2 mol/kg
By elevation in boiling point relation

QUESTION: 169

In Duma‘s method for estimation of nitrogen, 0.25 g of an organic compound gave 40 mL of nitrogen
collected at 300 K temperature and 725 mm pressure. If the aqueous tension at 300K is 25mm, the
percentage of nitrogen in the compound is :

Solution:

0.25 g 40 mL N2 at 300K, 725 mm pressure
Aq. tension at 300 K is 25 mm
725 - 25 = 700 mm
Temp. 300 K , Mass of the sub 0.25 g , Vol. of moist nitrogen = 40 mL

QUESTION: 170

The species Ar, K+ and Ca2+ contain the same number of electrons. In which order do their radii
increase ?

Solution:

Ca2+ < K+ < Ar
 Ar, K+ and Ca2+ are isoelectronic i.e with the same number of electrons, 18. For isoelectronic species, ionic radii decrease with increases in effective (relative) positive charge. Also Ar, K and Ca belong to the same period.

QUESTION: 171

Because of lanthanoid contraction, which of the following pairs of elements have nearly same atomic
radii ? (Numbers in the parenthesis are atomic numbers).

Solution:

QUESTION: 172

The number of d-electrons in Fe2+ (Z = 26) is not equal to the number of electrons in which one of the
following ?

Solution:

QUESTION: 173

Given :


Which of the given compounds can exhibit tautormerism ?

Solution:

In keto-enol tautomerism,

QUESTION: 174

Which one of the following electrolytes has the same value of van‘t Hoff‘s factor (i) as that of
Al2(SO4)3 (if all are 100% ionised)

Solution:

QUESTION: 175

Maximum bond angle at nitrogen is present in which of the following ?

Solution:

In all of the four molecules NO2- and NO2 have one lone pair thus bond angle is less 120 in the case of NO2- and more than 120 in the case of NO2 but in the NO3- there is no lone pair hence all are bonding pairs leading to an ideal bond angle of 120.
In NO2+, the is no lone pair only bond pair exist thus leading a bond angle is 180.

QUESTION: 176

The reaction of C6H5CH = CHCH3 with HBr produces :

Solution:

QUESTION: 177

Which property of colloidal solution is independent of charge on the colloidal particles ?