12th NEET 21st May Test Paper - Solution - YLC Academyeducation.ylc.co.in/wp-content/uploads/2013/08/12th-NEET-21st-May... · Q1 The dimensional formula of a real velocity is ] ...

12th NEET 21st May Test Paper Solution

101, Blue Diamond Complex, Fatehgunj, Vadodara-02 .Tel. No. 2787268 / 2750018 / 2782232

2

Subject-PHYSICS Part : 1

SECTION-A

(NEXT FOURTY FIVE QUESTIONS: SINGLE CHOICE – ONLY ONE CORRECT ANSWER)

Q1 The dimensional formula of a real velocity is

(a.) ]TL[M 120 (b.) ]TL[M 120 (c.) ]TL[M 120 (d.) ]TL[M 120

Sol. (c)

timeareavelocityAreal

Q2 What is the fractional error in g calculated from ?/2 gT Given fraction errors in T and l are x

and y respectively.

(a.) yx (b.) yx (c.) yx 2 (d.) yx 2

Sol. (c)

From 224;2

Tg

gT

)2(2 xyT

Tgg

Q3 A particle starting from rest falls from a certain height. Assuming that the acceleration due to gravity remain the

same throughout the motion, its displacements in three successive half second intervals are 21 , SS and 3S then

(a.) 9:5:1:: 321 SSS (b.) 5:3:1:: 321 SSS (c.) 3:2:9:: 321 SSS (d.) 1:1:1:: 321 SSS

Sol. (b)

221

2

1 )1(21,

21

21 gSSgS

321

2

23

21 SSSg

By solving we get

5:3:1:: 321 SSS

Q4 A particle moves in a circle of radius cm25 at two revolutions per second. The acceleration of the particle in

2secondpermeter is



3

(a.) (b.) 8 (c.) 4 (d.) 2

Sol. (c)

Here sec21

T the required centripetal acceleration for moving in a circle is

2222

)/2()( Trrr

rr

vaC

So 222 0.425.16)5.0/2(25.0 Ca

Q5 The velocity of a projectile at the initial point A is )ˆ3ˆ2( ji m/s. It’s velocity (in m/s) at point B is

(a.) ji ˆ3ˆ2 (b.) ji ˆ3ˆ2 (c.) ji ˆ3ˆ2 (d.) ji ˆ3ˆ2

Sol. (b)

At point B the direction of velocity component of the projectile along Y -axis reverses.

Hence, jiVBˆ3ˆ2

Q6 The coordinates of a moving particle at any time t are given by 2tax and .2tby The speed of the

particle is

(a.) )(2 bat (b.) )(2 22 bat (c.) )(2 22 bat (d.) )( 22 ba

Sol. (b)

,22 tbta jir tbatdtd 22 jirv

Magnitude of )44( 2222 tbta v

)(2 22 bat

Q7 The elevator shown in fig. is descending with an acceleration of .m/s2 2 The mass of the block 5.0A kg.

The force exerted by the block A on block B is



4

(a.) N2 (b.) N4 (c.) N6 (d.) N8

Sol. (b)

N41525.0105.0 mamgR

Q8 A 40 kg slab rests on frictionless floor as shown in fig. A 10 kg block rests on the top of the slab. The static

coefficient of friction between the block and slab is 0.60 while the kinetic friction is .40.0 The 10 kg block is

acted upon by a horizontal force of 100 N. If ,m/s9.8 2g the resulting acceleration of the slab will be:

(a.) 2m/s0.98 (b.) 2m/s1.47 (c.) 2m/s1.52 (d.) 2m/s6.1

Sol. (a)

Force on the slab kg)40(m reaction of frictional force on the upper block

ga k 1040 or 2m/sec0.98a

Q9 A uniform chain of length 2 m is kept on a table such that a length of 60 cm hangs freely from the edge of the

table. The total mass of the chain is 4 kg. What is the work done in pulling the entire chain on the table?

(a.) J12 (b.) J6.3 (c.) J2.7 (d.) J1200

Sol. (b)

Mass of over hanging chain kg)6.0(24' m

Let at the surface 0PE

C.M. of hanging part m3.0 below the table

30.0106.024' gxmU i

J6.3' gxmU Work done in putting the entire chain on the table

Q10 The work done in stretching a spring of force constant k from length 1 and 2 is

(a.) )( 21

22 k (b.)

)(21 2

122 k

(c.) )( 12 k (d.) )(

2 12 k

Sol. (b)



5

)(21

21

21 2

122

21

22 kkkW

Q11 When the kinetic energy of a body is increased to three times, then the momentum increases

(a.) 6 times (b.) 732.1 times (c.) 2 times (d.) 2 times

Sol. (b)

If P momentum, K kinetic energy, then

22

212

1 2,2 mKPmKP

33

1

1

1

2

2

1

2

KK

KK

PP

732.113

1

2 PP

Q12 Force F on a particle moving in a straight line varies with distance d as shown in the figure. The work done

on the particle during its displacement of 12 m is

(a.) J18 (b.) J21 (c.) J26 (d.) J13

Sol. (d)

Work done = area under F - d graph

)712(221)]37(2[

J.1358

Q13 A stick of length L and mass M lies on a frictionless horizontal surface on which it is free to move in any

way. A ball of mass m moving with speed v collides elastically with the stick as shown in fig.

If after the collision ball comes to rest, then what should be the mass of the ball?

(a.) Mm 2 (b.) Mm (c.) 2/Mm (d.) 4/Mm

Sol. (d)

Applying the law of conservation of momentum

VMvm … (1)

By conservation of angular momentum



6

12)2/(

2MLLvm … (2)

As the collision is elastic, we have

222

21

21

21 IVMvm … (3)

Substituting the values, we get 4/Mm

Q14 A solid cylinder of mass m & radius R rolls down inclined plane without slipping. The speed of its C.M.

when it reaches the bottom is

(a.) gh2 (b.) 3/4gh (c.) gh4/3 (d.) gh4

Sol. (b)

Q15 A rod PQ of mass M and length L is hinged at end .P The rod is kept horizontal by a massless string tied to

point Q as shown in figure. When string is cut, the initial angular acceleration of the rod is

(a.) Lg / (b.) Lg /2 (c.)

Lg

32

(d.)

Lg

23

Sol. (d)

Weight of the rod will produce the torque



7

2

2mLILmg

3

2

rodMLI

Hence, angular acceleration Lg

23

Q16 A solid cylinder of mass kg20 rotates about its axis with angular speed 100 rad/s. The radius of the cylinder

is 0.25 m. The K.E. associated with the rotation of the cylinder is

(a.) J3025 (b.) J3225 (c.) J3250 (d.) J3125

Sol. (d)

Q17 A steel rod of radius mm10R and length cm100L is stretched along its length by a force

N.1028.6 4F If the Young’s modulus of steel is ,N/m102 211Y the percentage elongation in the

length of the rod is:

(a.) 100.0 (b.) 314.0 (c.) 015.2 (d.) 549.1

Sol. (a)

Percentage elongation in the wireAYF

10001

102)01.0()1(1028.6

112

4

Q18 The density of ice is x gram/litre and that of water is y gram/litre. What is the change in volume when m

gram of ice melts?

(a.) )( yxymx (b.) )/( xym (c.)

xym 11

(d.) xxy /)(

Sol. (c)

Volume of m g ice xm / and volume of m g of water ./ ym So change in volume

xym

xm

ym 11

Q19 8 mercury drops coalesce to form one mercury drop, the energy changes by a factor of

(a.) 1 (b.) 2 (c.) 4 (d.) 6

Sol. (c)



8

Q20 In the figure, the velocity 3V will be

(a.) Zero (b.) 1ms4 (c.) 1ms1 (d.) 1ms3

Sol. (c)

Q21 The fraction of a floating object of volume 0V and density 0d above the surface of liquid of density d will be

(a.)

0

0

ddd

(b.)

ddd 0

(c.)

dd0

(d.)

0

0

dddd

Sol. (b)

Let x be the fraction of volume of object floating above the surface of the liquid.

As weight of liquid displaced = weight of object

Q22 A particle moves such that its acceleration ''a is given by bxa where x is the displacement from

equilibrium position and b is constant. The period of oscillation is

(a.) b/2 (b.) b/2 (c.) b/2 (d.) b/2

Sol. (b)



9

bxb

xT /22onacceleratintdisplaceme2

Q23 An instantaneous displacement of a simple harmonic oscillator is ).4/(cos tAx Its speed will be

maximum at time (a.) 4/ (b.) 2/ (c.) / (d.) /2

Sol. (a)

Q24 In the fig. 1S and 2S are identical springs. The oscillation frequency of the mass m is .f If one spring is

removed, the frequency will become

(a.) f (b.) 2f (c.) 2f (d.) 2/f

Sol. (d)

Q25 The displacement of a S.H.M. doing particle when K.E. = P.E. (amplitude 4 cm) is

(a.) cm22 (b.) cm2 (c.) cm

21

(d.) cm2

Sol. (a)



10

Q26 A uniform pole of length L2 is laid on smooth horizontal table as shown in figure. The mass of pole is

M and it is connected to a frictionless axis at .O A spring with force constant k is connected to the other end.

The pole is displaced by a small angle from equilibrium position and released such that it performs small

oscillations. Then

(a.)

kM30

(b.)

Mk

30 (c.)

Mk3

0 (d.)

Mk

20

Sol. (c)

Q27 If the speed of a transverse wave on a stretched string of length 1 m is 60 m/s, what is the fundamental

frequency of vibration?

(a.) Hz10 (b.) Hz30 (c.) Hz40 (d.) Hz70

Sol. (b)

Hz3012

602

l

vv

Q28 A whistle of frequency 1000 Hz is sounded on a car travelling towards a cliff with velocity of 1sm18

normal to the cliff. If ,sm303 1c then the apparent frequency of the echo as heard by the car driver is

nearly

(a.) Hz1115 (b.) Hz115 (c.) Hz67 (d.) Hz2.47

Sol. (a)

By the concept of accoustic, the observer and source are moving towards each other, each with a velocity of



11

.sm18 1

Hz111510001833018330'

v

Q29 A source X of unknown frequency produces 8 beats per second with a source of Hz250 and 12 beats per

second with a source of Hz.270 The frequency of the source X is

(a.) Hz242 (b.) Hz258 (c.) Hz282 (d.) Hz262

Sol. (b)

The total momentum will be zero and hence velocity will be zero just after collision. The pull of earth will

make it fall down.

Q30 A fork of unknown frequency gives four beats/sec when sounded with another of frequency 256. The fork is

now loaded with a piece of wax and again four beats/sec are heard. Then the frequency of the unknown fork is

(a.) Hz256 (b.) Hz252 (c.) Hz264 (d.) Hz260

Sol. (d)

Freq. of unknown fork 2604256 or 252

As frequency decreases on loading, therefore, original freq. of unknown fork Hz260

Q31 The electric field strength at a distance r from a charge q is .E What will be electric field strength if the

distance of the observation point is increased to ?2 r

(a.) 2/E (b.) 4/E (c.) 6/E (d.) 3/E

Sol. (b)

As new distance r2 and electric field due to single charge, ,12r

E therefore, new intensity .4/E

Q32 In a region of space having a uniform electric field ,E a hemispherical bowl of radius r is placed. The electric

flux through the bowl is

(a.) RE2 (b.) ER24 (c.) ER22 (d.) ER2

Sol. (c)

.20cos)2(cos)( 22 ErrEdsE

Q33 An electric dipole when placed in a uniform electric field E will have minimum potential energy if the dipole

moment makes the following angle with .E

(a.) (b.) 2/ (c.) Zero (d.) 2/3

Sol. (c)



12

cosEpEpU p

,)( minimum pEU p when 0

Q34 If a dipole of dipole moment

p is placed in a uniform electric field ,

E then torque acting on it is given by

(a.)

Ep . (b.)

Ep (c.)

Ep (d.)

Ep

Sol. (b)

Given: Dipole moment of the dipole

p and uniform electric field .

E Torque )( Either force

perpendicular distance between the two forces sinqaE or sinpE or

Ep (vector form)

Q35 Two particle of equal mass m and charge q are placed at a distance of 16 cm. They do not experience any

force. The value of mq

is

(a.) 1 (b.)

G0

(c.)

04G

(d.) G04

Sol. (d)

They will not experience any force if |||| eG FF

22

2

022

2

)1016(.

41

)1016(

qmG

G

mq

04

Q36 Two identical thin rings, each of radius a meter, are coaxially placed at a distance R meter apart. If 1Q

coulomb and 2Q coulomb are respectively the charges uniformly spread on the two rings, the work done in

moving a charge q coulomb from the centre of one ring to that of the other is

(a.) Zero (b.)

aQQq

0

21

24)12()(

(c.)

aQQq

0

21

4)(2

(d.)

aQQq

0

21

24)12()(

Sol. (b)

Q37 There exists a non-uniform electric field along x -axis as shown in the figure below. The field increases at a

uniform rate along +ve x -axis. A dipole is placed inside the field as shown. Which one of the following is

correct for the dipole?

(a.) Dipole moves along positive x -axis and undergoes a clockwise rotation



13

(b.) Dipole moves along negative x -axis and undergoes a clockwise rotation

(c.) Dipole moves along positive x -axis and undergoes a anticlockwise rotation

(d.) Dipole moves along negative x -axis and undergoes a anticlockwise rotation

Sol. (d)

The dipole is placed in a non-uniform field, therefore a force as well as a couple

acts on it. The force on the negative charge is more )( EF and is directed

along negative x -axis. Thus the dipole moves along negative x -axis and rotates

in an anticlockwise direction.

Q38 Two conducting spheres of radii 1r and 2r are equally charged. The ratio of their potentials is

(a.) 21 / rr (b.)

12 / rr (c.) 22

21 / rr (d.) 2

12

2 / rr

Sol. (b)

Q39 The electric potential due to a small electric dipole at a large distance r from the centre of the dipole is

proportional to

(a.) r (b.) r/1 (c.) 2/1 r (d.) 3/1 r

Sol. (c)

Due to small dipole, .12r

V

Q40 An electron of mass m and charge e is accelerated from rest through a potential difference V in vacuum. Its

final speed will be

(a.)

mVe2

(b.)

mVe

(c.) meV 2/ (d.) meV /

Sol. (a)

Q41 Two parallel metal plates having charges Q and Q face each other at a certain distance between them. If

the plates are now dipped in kerosene oil tank, the electric field between the plates will

(a.) Remain same (b.) Become zero (c.) Increases (d.) Decrease

Sol. (d)



14

Q42 BA, and C are three points in a uniform electric field. The electric potential is

(a.) maximum at B (b.) maximum at C

(c.) same at all the three points BA, and C (d.) Maximum at A

Sol. (a)

Potential at BVB, is maximum

ACB VVV

Q43 Identical charges q each are placed at 8 corners of a cube of each side .b Electrostatic potential energy of a

charge q which is placed at the centre of cube will be

(a.)

bq

0

224

(b.)

bq

0

228

(c.)

bq

0

2

34

(d.)

bq

0

28

Sol. (c)

Q44 In a hollow spherical shell, potential )(V changes with respect to distance (s) from centre as

(a.)

(b.)

(c.)

(d.)

Sol. (b)

In shell, q charge is uniformly distributed over its surface, it behaves as a conductor.

V potential at surface R

q

04 and inside

RqV

04



15

Q45 Figure shows three circular arcs, each of radius R and total chargé as indicated. The net electric potential at the

centre of curvature is

(a.)

RQ

02

(b.)

RQ

04

(c.)

RQ

0

2

(d.)

RQ

0

Sol. (a)



16

Subject-CHEMISTRY Part : 2

SECTION-A

(NEXT FOURTY FIVE QUESTIONS: SINGLE CHOICE – ONLY ONE CORRECT ANSWER)

Q1 Number of moles in OHg1.8 2 is equal to number of moles in g18:I glucose; g6:II urea; g34.2:III

sucrose

(a.) I, II, III (b.) I, II (c.) I, III (d.) II, III

Sol. (a)

mol0.1181.8OHg1.8 2

g18:I glucose mol0.118018

g6II urea mol0.1606

g34.2III sucrose mol0.134234.2

Q2 Number of atoms in Mgg12 2412 us equal to

(a.) Oxygen atoms in 2COg11 (b.) Hydrogen atoms in 4CHg4

(c.) Nitrogen atoms in 42ONg46 (d.) Sulphur atoms in 322 OSNag79

Sol. (a)

Q3 If Aufbau rule is not used, 19th electron in 21)(ZSc will have

(a.) 0,3 ln (b.) 1,3 lm (c.) 2,3 ln (d.) 0,4 ln

Sol. (c)

Q4 Which is correct order of size of F,O,O 2 and F ?

(a.) FFOO2 (b.) FFOO 2 (c.) OFFO2 (d.) FOFO2

Sol. (a)

FO

FO Thus, FFOO2

FO2



17

Q5 Which of the following have identical bond order?

(I) CN (II) 2O (III) NO (IV) CN

(a.) I, III (b.) II, IV (c.) I, II, III (d.) I, IV

Sol. (a)

Q6 Among the following species, identify the isostructural pairs 33333 HN,OH,BF,NO,NF

(a.) ]NO,[NF 33 and ]OH,[BF 33

(b.) ]HN,[NF 33 and ]BF,[NO 33

(c.) ]OH,[NF 33 and ]BF,[NO 33

(d.) ]OH,[NF 33 and ]BF,[HN 33

Sol. (c)

Q7

2O gas at STP contained in a flask was replaced by 2SO under same conditions. The weight of 2SO will be

(a.) Equal to that of 2O (b.) Half that of 2O (c.) Twice that of 2O (d.) One-fourth of 2O

Sol. (c)

Number of moles remains unchanged. One mole 2SO replaces one mole of ,O2 hence

22 SOg64Og32

Q8 The average molecular speed is greatest in which of the following gas samples?

(a.) 2Nmol1.0 at K560 (b.) mol0.50 of Ne at K500

(c.) 2COmol0.20 at K440 (d.) mol2.0 of He at K140

Sol. (d)



18

MTuav but independent of number of moles

Q9 A L1 flask contains 2Og32 gas at C.27 What mass of 2O must be released to reduce the pressure in the

flask to atm12.315 ?

(a.) g8 (b.) g16 (c.) g42 (d.) g0

Sol. (b)

Q10 Internal energy for one mole of a monoatomic ideal gas is

(a.) RT

23

(b.) RT

25

(c.)

RT27

(d.) RT4

Sol. (a) Q11 For the reaction, (g)Cl2Cl(g) 2

(a.) veΔSve,ΔH (b.) veΔSve,ΔH

(c.) veΔSve,ΔH (d.) veΔSve,ΔH

Sol. (d)

Q12 Given the standard enthalpies at C,25 in ,molkJ 1 for the following two reactions

1.234),(2)(23)(

23)( 232 HsFegCOsCsOFe

5.393),()()( 22 HgCOgOsC

The H value for (s)O2Fe(g)3O4Fe(s) 322 is calculated as

(a.) 1.234)5.393(

23

(b.)

1.234)5.393(23

(c.) 1.2345.393 (d.) 1.234(2)5.393(3

Sol. (d)

Q13 The dissociation energy of 4CH and 62HC to convert them into gaseous atoms are 360 and molkcal620

respectively. The bond energy of CC bond is

(a.) 1molkcal260 (b.) 1molkcal180 (c.) 1molkcal130 (d.) 1molkcal80

Sol. (d)



19

Q14 For the reaction, (s)COONHNH 42 (g)CO(g)2NH 23

The equilibrium constant .atm102.92K 35p

The total pressure of the gaseous products when mole1 of

reactant is heated, will be

(a.) atm0.0194 (b.) atm0388.0 (c.) atm0582.0 (d.) atm0667.0

Sol. (c)

Q15 Equilibrium constant K changes with temperature. At K,300 equilibrium constant is 25 and at K400 it is

.10 Hence, backward reaction will have energy of activation

(a.) Equal to that of forward reaction (b.) Less than that of forward reaction (c.) Greater than that of forward reaction (d.) Given values are not sufficient to explain given statement

Sol. (c)

K decreases with increase in temperature. Thus, forward reaction is exothermic.

aE activation energy of forward reaction

'Ea activation energy of backward reaction



20

Q16 Assuming %100 ionization which will have maximum pH?

(a.) ClNHM0.01 4 (b.) 424 SO)(NHM0.01 (c.)

434 PO)M(NH0.01 (d.) Equal

Sol. (a)

Q17 pH of a mixture of M1 benzoic acid 4.20)(pK a and M1 sodium benzoate is .5.4 In mL300 buffer,

benzoic acid is

(a.) mL200 (b.) mL150 (c.) mL100 (d.) mL50

Sol. (c)

Q18 Out of the following redox reactions

I : O2HONNONH 2234

II : O2HNNONH 22Δ

24

III : 23Δ

5 ClPClPCl

disproportionation is not shown in (a.) I, II (b.) II, III (c.) I, III (d.) I, II and III

Sol. (d)



21

Q19 Which has maximum oxidation number of the underlined atom in the following?

(a.) 24OMn (b.)

5OCr (c.) 22ClOCr (d.) Equal

Sol. (d)

Q20 Which is a source of nascent hydrogen?

I : HCl,dil.Zn II : NaOHCH3

III : Electrolysis of OH2 IV : Silent electric discharge

(a.) I, II (b.) II, III (c.) I, II, III, IV (d.) IV

Sol. (a) Q21

2CO gas along with solid (Y) is obtained when sodium salt (X) is heated. (X) is again obtained when 2CO

gas is passed into aqueous solution (Y). (X) and (Y) are

(a.) ONa,CONa 232 (b.) NaOH,CONa 32 (c.) 323 CONa,NaHCO (d.)

332 NaHCO,CONa

Sol. (c)

Q22 The right order of the solubility of sulphates of alkaline earth metals in water

(a.) Be > Ca > Mg > Ba > Sr (b.) Mg > Be > Ba > Ca > Sr (c.) Be > Mg > Ca > Sr > Ba (d.) Mg > Ca > Ba > Be > Sr

Sol. (c)

Q23 In the reaction, COAClCOB 232 A is

(a.) 2BCl (b.)

22ClB (c.) 2CCl (d.)

3BCl

Sol. (d)



22

Q24 The best oxidizing agent of the following oxides is

(a.) 2SnO (b.)

2PbO (c.) HgO (d.) MgO

Sol. (b)

:PbO2 due to inert pair effect stability of lower state decreases

24 Pb2ePb

24 SnSn

22

2 HfHg

Q25

In the nomenclature of

CH3

OH

priority order is

(a.) CCOHCH3 (b.) CCCHOH 3

(c.) 3CHOHCC (d.) OHCCCH3

Sol. (d)

OH then C)(C and then 3CH

CH3

OH

1 23

Q26

IUPAC name of the following compound is CH2CH3

CH3

(a.) 1-ethyl-2-methylcyclohexane (b.) 1-methyl-2-ethylcyclohexane (c.) 1-methyl-6-ethylcyclohexane (d.) 1-ethyl-6-methylcyclohexane

Sol. (a)

Q27 The compound, whose stereo-chemical formula is written below, exhibits x geometrical isomers and y optical

isomers.

The values of x and y are

(a.) 4 and 4 (b.) 2 and 2 (c.) 2 and 4 (d.) 4 and 2

Sol. (b)

x = cis and trans

y = d and l



23

Q28 What are the type of isomers in following pairs?

(a.) Conformers (b.) Position (c.) Optical (d.) Geometrical

Sol. (a)

Q29 Relative stabilities of the following carbocation will be in order

(a.) I < II < III < IV (b.) IV < III < II < I (c.) IV < II < III < I (d.) II < IV < III < I

Sol. (c)

Benzyl carbocation is more stable thean alkyl )HC(CH 23

OCH3 and 3CH both stabilize benzyl

carbocation O(CH3 is more stabilizing than 3CH )

IV < II < III < I

Q30 Which of the following decolourises 2Br water and also gives colour with 3FeCl solution?

(a.) 23 CHCHCH (b.)

OH

(c.) OH

(d.) CH2Cl

Sol. (b) Q31 Which has maximum boiling point and melting point out of

I II III (a.) I in both case (b.) I, II (c.) I, III (d.) II, I

Sol. (c)

Q32

Alkene



24

A is

(a.)

(b.)

(c.)

(d.)

Sol. (a)

Q33

A is (a.)

(b.)

(c.)

(d.)

Sol. (a)

Q34 Benzene on oxidation with 52OV produce

(a.) Toluene (b.) Benzaldehyde (c.) Benzoic acid (d.) Maleic anhydride

Sol. (d)

Q35 Which one of the following will be aromatic?

(a.)

(b.)

(c.)

(d.)

Sol. (d)

Q36 Consider the following compounds.

I : OCl2 II : 4XeF III : 3BF IV : ClCHCH 23

Which of the above example(s) will have non-zero value of dipole moment?

(a.) I, II, III (b.) II, III, IV (c.) I, IV (d.) II

Sol. (c)

Q37 A salt AB crystallises in the CsC1 structure. The anions at the corners touch each other and the cation in the

centre. Hence, radius ratio rr /

(a.) 225.0 (b.) 441.0 (c.) 625.0 (d.) 732.0

Sol. (d)



25

Q38 A solid has a structure in which W atoms are located at the cube corners of the unit cell, O atoms are located at

the cube edges and the Na atoms at the cube centres. Lattice is of the type with formula

(a.) Simple cubic, 3NaWO (b.) Simple cubic, 32WONa

(c.) Tetrahedral, 3NaWO (d.) Body-centred, 3NaWO

Sol. (a)

Q39 The edge length of the NaCl unit cell is ... if radius of Na is pm97 and radius of Cl is pm.181

(a.) pm556 (b.) pm278 (c.) pm139 (d.) pm120

Sol. (a)

Q40 Consider the following statements.

I : If an 2Fe is missing from its lattice site in FeO, then there must be two 3Fe ions somewhere in the lattice

to balance the electrical charges.

II : Crystals with metal deficiency defects are called super-conductors.

III : Crystals with metal deficiency defects are called semiconductors.

Select the correct alternate.

(a.) I, II (b.) I, III (c.) II only (d.) I only

Sol. (d) Q41 The solubility of (g)N 2 in water exposed to the atmosphere, when the partial pressure is mm,593 is

M.105.3 4 Its solubility at mm760 and at the same temperature is

(a.) M104.1 4 (b.) M108.6 4 (c.) M1500 (d.) M2400

Sol. (b)



26

Q42 All of the water in a M 0.20 solution of NaC1 was evaporated and a mol 0.150 of NaCl was obtained.

What was the original volume of the sample?

(a.) mL30 (b.) mL333 (c.) mL750 (d.) mL1000

Sol. (c)

Q43 In which case van’t Hoff factor is maximum?

(a.) 50%KCl, ionized (b.) 40%,SOK 42 ionized (c.) %30,FeCl3 ionized (d.) 20%,SnCl 4 ionized

Sol. (c)

Q44 Osmotic pressure of insulin solution at K298 is found to be atm.0.0072 Hence, height of water column due

to this pressure is

[given g/mL]13.6d(Hg)

(a.) cm0.76 (b.) cm70.0 (c.) cm4.7 (d.) cm76

Sol. (c)

Q45 Vapour density of (g)PCl5 dissociating into (g)PCl3 and (g)Cl2 is .100 Hence, van’t Hoff factor for the

case

(g)PCl5 (g)Cl(g)PCl 23 is

(a.) 85.1 (b.) 70.3 (c.) 085.1 (d.) 0425.1

Sol. (d)



27



28

Subject-BIOLOGY Part : 3

SECTION-A

(NEXT NINETY QUESTIONS: SINGLE CHOICE – ONLY ONE CORRECT ANSWER)

Q1 What is the time period between DUBB and LUBB sound?

(a.) s0.3 (b.) s0.5 (c.) s0.7 (d.) C0.8

Sol. (b)

Q2 Dental formula of monophyodont teeth in humans?

(a.)

21022102

(b.)

21232123

(c.)

00130013

(d.)

00210021

Sol. (d)

Q3 The voltage of Hyperpolarization is

(a.) Negative (b.) Positive (c.) Neutral (d.) None

Sol. (a)

Q4 Ions necessary for synapse to occur is

(a.) 2Mg (b.) Na (c.) 2Ca (d.) K

Sol. (c)

Q5 Nerves entering into diaphragm is known

(a.) Cardiac (b.) Nervous (c.) Phrenic (d.) Nephric

Sol. (c)

Q6 Serum is equal to

(a.) Blood-clotting factors (b.) Blood-plasma (c.) Plasma-ions (d.) Blood- (plasma + clotting factors)

Sol. (d)

Q7 Can AB Blood group person donate blood to AB blood group person?

(a.) Yes (b.) No (c.) Maybe (d.) Can’t judge

Sol. (b)

Q8 ______ % of population has Rhesus antigen on their RBC membrane

(a.) 60 (b.) 70 (c.) 80 (d.) 90

Sol. (c)



29

Q9 Which of the following will not be absorbed in the absence of carries molecule?

(a.) Monoglyceride (b.) Cholesterol (c.) Fructose (d.) Fatty aud

Sol. (c)

Q10 In which layer of the wall of alimentary canal, secretory glands are presents

(a.) serosa (b.) Mucosa (c.) Muscularis (d.) Submucosa

Sol. (b)

Q11 It is an outcome of irrequalrities in metalolism of the nitrogenous waste

(a.) Osteoporosis (b.) Gouty arthritis (c.) Osteoarthritis (d.) Rheumatoid arthritis

Sol. (b)

Q12 Structurally, what are olfactory nerve cells?

(a.) Multipolar neuron (b.) Unipolar neuron (c.) Neuro chemically specialized neuron (d.) Bipolar neuron

Sol. (d)

Q13 Auerbash’s plexus is present is ______?

(a.) Serosa (b.) Submucosa (c.) muscularis (d.) Mucosa

Sol. (c)

Q14 Fat absorption occurs in ______? (a.) Crypts of Lieberkuln (b.) Stomach (c.) Lacteals (d.) Capillaries

Sol. (c)

Q15 What is Glisson’s capsule?

(a.) Covering of stomach (b.) Covering of diaphragm (c.) Covering of intestine (d.) Covering of liver

Sol. (d)

Q16 Peptic cell secretes ______?

(a.) Mucus (b.) HCl (c.) Pepsinogen (d.) Intrinsic factor

Sol. (c)

Q17 While exercising, a person is breathing additional volume of air. The volume is ______

(a.) 500 ml (b.) 1000-1100 ml (c.) 6000-8000 ml (d.) 2500-3000 ml

Sol. (d)

Q18 Every 100 ml of oxygenated blood can deliver around ______ ml of 2O to the tissues under normal physiological condition.

(a.) 5 (b.) 10 (c.) 20 (d.) 50

Sol. (a)

Q19 Which cells does Basophils secrete?

(a.) Heparin and Dopamine (b.) Histamine, heparin, Dopamine (c.) Epinephrine, Dopamine, Serotonin (d.) Histamine, Serotonin, heparin



30

Sol. (d)

Q20 Flame cells are excretory structured is _______

(a.) Plathelminthes, some annelids and cephalochordate

– Amphious

(b.) Coelentrates, platyhelminthes, some molluse

(c.) Molluscs and echinoderms (d.) Annelids, some platyhelminthes and

cephalochordate – Amphiolyus

Sol. (a)

Q21 ADH is secreted by

(a.) Sdenohypophyses (b.) Neurohypophysis (c.) Hypothalamees (d.) Adrenal gland

Sol. (b)

Q22 Which band retains its length during muscle contraction?

(a.) I band (b.) H zone (c.) A band (d.) A and I band

Sol. (c)

Q23 What is the attachment point of false ribs?

(a.) Vertebral column and sternum (b.) Only vertebral column (c.) Vertebral column and 7th rib cartilage (d.) Vertebral column and 8th rib cartilage

Sol. (c)

Q24 Co-transporter transports …..

(a.) Na3 inwards, 2K outwards (b.) Na3 outwards, 2K inwards

(c.) 3K inwards, Na2 outwards (d.) 3K outwards, Na3 inwards

Sol. (b)

Q25 Diencephalon has this following parts

(a.) Epithalamus only (b.) Epithalamus and Hypothalamus (c.) Amygdala, hippocampus, nucleii accumbence (d.) Epithalamus,Hypothalamus, thalamus

Sol. (d)

Q26 The coloured partion of the eye is

(a.) Iris (b.) Pupil (c.) Lens (d.) cilliary

Sol. (a)

Q27 The pituitary gland is located in a body cavity called ______

(a.) Foramen magnum (b.) Corpus callosum (c.) Ethmoid bone (d.) Sella tursica

Sol. (d)

Q28 The keys are based on the contrasting characters occurs generally in a pairs called

(a.) Couplet (b.) di-plet (c.) Couple (d.) duplicate

Sol. (a)



31

Q29 Keys are generally ______ in nature

(a.) Biochemical (b.) Analytical (c.) Biological (d.) Physical

Sol. (b)

Q30 Which of the following is properly matched?

(a.) Arthropoda – Insecta – Spider (b.) Mollusca – Cephalopoda – Unio (c.) Platyhelminthes – Trematoda – Planaria (d.) Echinodermata – Asteroidea – Starfish

Sol. (d)

Q31 Tissues are absent in the body of

(a.) Sponge (b.) Annelida (c.) Platyhelminthes (d.) arthropoda

Sol. (a)

Q32 Tube feet are locomotary organs of

(a.) Spider (b.) Reptile (c.) Star fish (d.) Cat fish

Sol. (c)

Q33 Match the following list of animals with their level of organization

Division of Labour Animal

A. Organ level i. Pheritima

B. Cellular aggregate level ii. Fasciola

C. Tissue level iii. Spongilla

D. Organ system level iv. Obelia

Choose the correct match showing division of labour with animal example. (a.) i-B, ii-C, iii-D and iv-A (b.) i-B, ii-D, iii-C and iv-A (c.) i-D, ii-A, iii-B and iv-C (d.) i-A, ii-D, iii-C and iv-B

Sol. (c)

Q34 Assertion : Hormones are carried to the target organs by blood.

Reason : Enzyme action quickens with rise in temperatue.

(a.) If both A and R are true and R is the correct explanation of A (b.) If both A and R are true but R is not the correct explanation of A (c.) If A is true but R is false (d.) If both A and R are false

Sol. (a)

Q35 Assertion : Blood is colourless in the insects.

Reason : Insect blood has no role in 2O transport.

(a.) If both A and R are true and R is the correct explanation of A (b.) If both A and R are true but R is not the correct explanation of A (c.) If A is true but R is false



32

(d.) If both A and R are false

Sol. (b)

Q36 Mast cells of connective tissue contain

(a.) Heparin and histamine (b.) Heparin and calcitonin (c.) Serotonin and melanin (d.) Vasopressin and relaxin

Sol. (a)

Q37 Choroids plexus is a network of

(a.) Lymph vessels (b.) Nerves (c.) Muscle fibres (d.) capillaries

Sol. (b)

Q38 Areolar connective tissue joins

(a.) Bones with bones (b.) Fat body with muscles (c.) Integument with muscles (d.) Bones with muscles

Sol. (c)

Q39 Keratinized dead layer of skin is made of

(a.) Stratified squamous (b.) Simple cuboidal (c.) Simple columnar (d.) Stratified columnar

Sol. (a)

Q40 Skin is an accessory organ of respiration in

(a.) Humans (b.) Frogs (c.) Rabbits (d.) lizards

Sol. (b)

Q41 In which one of the following organisms its excretory organs are correctly stated?

(a.) Humans-Kidneys, sebaceous glands and tear glands (b.) Earthworm-pharyngeal, integumentary and septal nephridia (c.) Cockroach-Malpighian tubules and enteric caeca (d.) Frog-Kidneys, skin and buccal epithelium

Sol. (b)

Q42 Heart of cockroach is

(a.) 13 chambered (b.) 29 chambered (c.) 9 chambered (d.) 6 chambered

Sol. (a)

Q43 In meiosis, 4 daughter cells are formed by two successive divisions in which:

(a.) Both divisions are equational (b.) Both are reductional (c.) First is equational and second is reductional (d.) First is reductional and second is equational

Sol. (d)

Q44 Synapsis occurs at:

(a.) Leptotene (b.) Zygotene (c.) Pachytene (d.) Diplotene

Sol. (b)

Q45 Spindle is formed at:

(a.) Early prophase (b.) Late prophase (c.) Late metaphase (d.) Anaphase



33

Sol. (b)

Q46 Function of centriole is:

(a.) Formation of spindle fibres (b.) Formation of nucleolus (c.) Initiation of cell division (d.) Formation of cell plate

Sol. (a)

Q47 Autosome is:

(a.) Acromatic (b.) Sex chromosome (c.) Chromosome other than sex chromosome (d.) Not a chromosome

Sol. (c)

Q48 The oxysomes are made of:

(a.) Glycoproteins (b.) Lipoprotein (c.) Phosphoproteins (d.) None of these

Sol. (b)

Q49 Aleurone grains are:

(a.) Fat (b.) Protein (c.) Carbohydrates (d.) Enzymes

Sol. (b)

Q50 - oxidation of fat takes place in:

(a.) Microsomes (b.) Glyoxysomes (c.) Mitochondria (d.) Ribosomes

Sol. (b)

Q51 The waxy substance associated with cell walls of cork cells is

(a.) Lignin (b.) Hemicellulose (c.) Suberin (d.) Cutin

Sol. (c)

Q52 Bacteria are regarded as primitive organisms because they

(a.) Possess incipient nucleus (b.) Are small, microscopic plants, which are not visible to the naked eyes (c.) Cause serious diseases to human beings, domesticated animals and crop plants (d.) Produce endospores, which are resistant to adverse conditions

Sol. (a)

Q53 Select the correct combination of characteristics for slime moulds.

(a.) Parasitic, spore dispersal by water, Plasmodium with walls (b.) Saprophytic, spore dispersal by aircurrents, Plasmodium without walls (c.) Parasitic, spore dispersal by air currents, Plasmodium without walls (d.) Saprophytic, spore dispersal by water, Plasmodium with walls

Sol. (b)

Q54 Fungal cell wall is composed of

(a.) Chitin (b.) Chitin or cellulose (c.) Hemicellulose (d.) Cellulose



34

Sol. (a)

Q55 Fruits are not found in gymnosperms because

(a.) They are not seedless (b.) They are not pollinated (c.) They have no ovary (d.) Fertilization does not takes place

Sol. (c)

Q56 Which one of the following is correctly matched?

(a.) Onion – Bulb (b.) Ginger - sucker (c.) Chlamydomonas – Conidia (d.) Yeast – Zoospores

Sol. (a)

Q57 Pineapple fruit develops from

(a.) Unilocular polycarpellary flower (b.) Multipistillate syncarpous flower (c.) Multilocular monocarpellary flower (d.) A cluster of compactly born flowers on an axis

Sol. (d)

Q58 Tyloses thickening is seen in

(a.) Collenchyma (b.) Phloem cells (c.) Ray parenchyma only (d.) Ray parenchyma and xylem cells

Sol. (d)

Q59 Passage cells are thin-walled cells found in

(a.) Endodermis of roots facilitating rapid transport of water from cortex to pericycle (b.) Phloem elements that serve as entry points for substances for transport to other plant parts (c.) Testa of seeds of enable emergence of growing embryonic axis during seeds germination (d.) Central region of style through, which the pollen tube grows towards the ovary

Sol. (a)

Q60 A cell placed in a strong salt solution, will shrink because

(a.) The cytoplasm will decompose (b.) Mineral salts will break the cell wall (c.) Salt will enter the cell (d.) Water will leave by exosmosis

Sol. (d)

Q61 A tree girdled up to xylem may survive for sometime but ultimately dies because

(a.) Water does not move upwards (b.) Sugar does not move upwards (c.) Sugar does not move downwards (d.) Water does not move downwards

Sol. (c)

Q62 Manganese is required in

(a.) Nucleic acid synthesis (b.) Plant cell wall formation (c.) Photolysis of water during photosynthesis (d.) Chlorophyll synthesis

Sol. (c)



35

Q63 Match the following and choose the correct combination from the options given.

Column I Column II

A. Sulphur 1. Chlorophyll

B. Zinc 2. Nitrogenase

C. Magnesium 3. Methionine

D. Molybdenum 4. Auxin

(a.) A-1, B-2, C-3, D-4 (b.) A-3, B-4, C-1, D-2 (c.) A-3, B-1, C-2, D-4 (d.) A-2, B-4, C-1, D-3

Sol. (b)

Q64 Carotenes and xanthophylls pigments absorb radiant energy and

(a.) Carry out photosynthesis to produce carbohydrates (b.) Do not take any part in photosynthesis (c.) Loose the energy as heat (d.) Transfer this energy to chlorophyll-a and b where, it is transformed into chemical energy

Sol. (d)

Q65 The correct sequence of cell organelles during photorespiration is

(a.) Chloroplast-Golgi bodies-mitochondria (b.) Chloroplast-rough endoplasmic reticulum-distyosomes (c.) Chloroplast-mitochondria-peroxisome (d.) Chloroplast-vacuole-peroxisome

Sol. (c)

Q66 Photochemical reactions in the chloroplasts are directly involved in

(a.) Fixation of carbon dioxide (b.) Synthesis of glucose and starch (c.) Formation of phosphoglyceric acid (d.) Photolysis of water and phosphorylation of ADP to ATP

Sol. (c)

Q67 Which of these steps in Krebs’ cycle indicated substrate level phosphorylation?

(a.) Conversion of succinyl acid to ketoglutaric acid (b.) Conversion of succinic acid to malic acid

(c.) Conversion of succinly Co-A to succinic acid (d.) Conversion of malic acid to oxaloacetic acid

Sol. (a)

Q68 Which of the following respiratory substrates requires the highest number of oxygen molecules for its complete

oxidation? (a.) Tripalmitin (b.) Triolein (c.) Tartaric acid (d.) Oleic acid

Sol. (b)

Q69 Mitochondrial electron transport chain is

(a.) Cyclic phosphorylation (b.) Oxidative phosphorylation (c.) Non-cyclic phosphorylation (d.) Photo-oxidation

Sol. (b)



36

Q70 Heteroblastic development refers to

(a.) Two types of spores on the same plant (b.) Any adult organ, which is physiologically different from juvenile structure (c.) Male and female sex organs on the same plant (d.) Vegetative growth and flowering in different seasons

Sol. (b)

Q71 Bananas can be prevented from over ripening by

(a.) Maintaining them at room temperature (b.) Refrigeration (c.) Dipping in ascorbic acid solution (d.) Storing in a freezer

Sol. (c)

Q72 Turgor movements occur in response to

(a.) Stimulation of amyloplasts (b.) Activation and deactivation of phytochromes (c.) Circadian rhythm (d.) Changes in K ion concentration

Sol. (d)

Q73 During drought, plants develop hormone

(a.) Indole acetic acid (b.) Naphthalene acetic acid (c.) Indolebutyric acid (d.) Abscisic acid

Sol. (d)

Q74 Antigibberellin is

(a.) Cycocel (b.) Plastoquinone (c.) IAA (d.) ubiquinone

Sol. (a)

Q75 The plant hormone produced by Rhizobium for nodulation is

(a.) IBA (b.) NAA (c.) 2, 4-D (d.) IAA

Sol. (d)

Q76 Which one of the following is the first step of glycolysis?

(a.) Breakdown of glucose (b.) Phosphorylation of glucose (c.) Conversion of glucose into fructose (d.) Dehydrogenation of glucose

Sol. (b)

Q77 What is the correct order of the stage of cellular respiration?

(a.) Krebs’ cycle – Electron transport chain – Glycolysis (b.) Electron transport chain – Krebs’ cycle – Glycolysis (c.) Glycolysis – Krebs’ cycle – Electron transport chain (d.) Glycolysis – Electron transport chain – Krebs’ cycle

Sol. (c)

Q78 Select the wrong statement.

(a.) When tripalmitin is used as a substrate in respiration, the RQ is 0.7 (b.) The intermediate compound which links glycolysis with Krebs’ cycle is malic acid (c.) One glucose molecule yields a net gain of 36 ATP molecules during aerobic respiration



37

(d.) One glucose molecule yields a net gain of 2 ATP molecules during fermentation

Sol. (a)

Q79 How many ATP molecules could maximally be generated from one molecule of glucose, if the complete

oxidation of one mole of glucose to 2CO and OH2 yields kcal686 and the useful chemical energy available

in the high energy phosphate bond of one mole of ATP is kcal12 ?

(a.) Two (b.) Thirty (c.) Fifty-seven (d.) One

Sol. (b)

Q80 At the time of germination of zygospore in spirogyra

(a.) All haploid nuclei are functional (b.) Only one haploid nucleus is functional (c.) Diploid nucleus does not divide (d.) Diploid nucleus divides mitotically

Sol. (d)

Q81 Compensation point is the value of a factor where there is

(a.) Beginning of photosynthesis (b.) Little photosynthesis (c.) Photosynthesis equal to rate of respiration (d.) Neither photosynthesis nor respiration

Sol. (d)

Q82 Which unicellular green alga used in flashing light experiment?

(a.) Chlorella (b.) Chlamydomonas (c.) Vaucheria (d.) oedogonium

Sol. (a)

Q83 The macronutrient, which is an essential component of all organic compounds, yet not obtained by plants from

soil, is

(a.) Nitrogen (b.) Carbon (c.) Phosphorus (d.) Magnesium

Sol. (b)

Q84 The minerals involved in water splitting reaction during photosynthesis are

(a.) Magnesium and chlorine (b.) Potassium and manganese (c.) Manganese and chlorine (d.) Molybdenum and manganese

Sol. (c)

Q85 The continuous excretion of watery substance from stump of a well-watered poted plant after cutting off the

shoot slightly above the base is due to

(a.) Root pressure (b.) Guttation (c.) Transpiration (d.) imbibition

Sol. (a)

Q86 Stoma opens, when

(a.) Guard cells swell due to an increase in water potential (b.) Guard cells swell by endosmosis due to influx of hydrogen ions (protons) (c.) Guard cells swell by endosmosis due to efflux of potassium ions (d.) Guard cells swell due to an decrease in their water potential



38

Sol. (d)

Q87 The length of different internodes in a culm of sugarcane is variable because of

(a.) Shoot apical meristem (b.) Position of axillary buds (c.) Size of leaf lamina at the node below each internode (d.) Intercalary meristem

Sol. (d)

Q88 In an isobilateral (monocot) leaf, the stomata are

(a.) Usually absent or less abundant in upper epidermis (b.) Usually absent or less abundant in lower epidermis (c.) Almost equally distributed in upper and lower epidermis (d.) Numerous in lower epidermis

Sol. (c)

Q89 True fruit differs from the false fruit as it is

(a.) Succulent and more tasty (b.) Capable of producing seeds (c.) Derived from ovary only (d.) Seedless

Sol. (c)

Q90 Who was the fist to give more scientific classification?

(a.) Linnaeus (b.) Aristotle (c.) Whittaker (d.) hooker

Sol. (a)

12th NEET 21st May Test Paper - Solution - YLC Academyeducation.ylc.co.in/wp-content/uploads/2013/08/12th-NEET-21st-May... · Q1 The dimensional formula of a real velocity is ] ...

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