KEAM 2021 Question Paper Physics Chemistry

Any malpractice or atry attempt to commit any kind of malpractice in
WARNING
the Examination will DISQUALIFY TIIE CANDIDATE.

PAPER_I PHYSICS & CHEMISTRY - 2021
Version Questio[ Booklet
Code A3 Serial Number : 6323741s
Time: 150 Minutes Number of Questions : 120 Maximum Marks : 480

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PRINTED PAGES 32

l. When two sound waves of slightly different ftequencies .fi and .fz are sounded
together, thed the tjme iDterval between successive maxima is

rA) I ,s,]*] icr I ro) I (E)f -f
I'L f, f, ' f,-f, f,"f, t "f,
2. The electric pote[tial at a point at a distance r due to afl elechic dipole is proportional
to

(A) @)r (L)r' (u) r- :lE),r
|--,
"'
An air capacitor and identical capacitor filled with dielectric medium of dielectric
constant 5 are connected in series to a voltage source of 12V. The fall of potential
across Ct and C2 are respectively \.

(A)2Vandl0V ' (B) l0Vand2V (C)6Vand6V
(D)4Vand8V (E)8Vand4V
work
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Phy-Chy-l-A3/2021 ,, rl ,
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4. The ratio of the magnitudes of electrostatic force between two prctons at a distarce
r alart to that between two glechons at the same distance of separation is

,/
{a2,l,r @) 2:t (c) t:2 @) 4:1 (E) t:4

When two charges are kept in air medium, at certain distance d apart, the force
betwee[ them is R Whetr they arc kept in a dielectric medium at the same distatrce of
separation, the force between them becomes F/2. Thef, the dielectric constant ofthe
medium is
,".\
(A) 5 I (By2 (c) 4 (D) 3 (E) 8
\/
The magnitude of tfie drift velocity per unit electric field is defined as

(B) rcsistivity
@-"0r," (C) conductivity
(D) cunent density (E) impedance

Space for rough work

1,, . t= F-q14L
?- -

{,
--n
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ylL"
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"r\) 6i
7_
7u'
V.r*
vi l\'.','-b;1 [ Bc, .F4

IE -\
.v,o -- W s," l\i L J' 14.

Phy-Chy-l-A312021 4

7. A Wheatstone network is balanced with respective resisto$ 5 O. l0 O. 20 O and
40 O in tbe P. 0. R and S arms. Ifa 40 C) resisror is connecred across .t alm. lhen rhe
bddge is again balarced by connecting

(A) 10O across R (B) l0O across p (C) 20O across 0
(D) 20Q across P (E) 10O across Q

If one cell is connected wrongly in a series combination of four cells each of e.m.f.
1.5 V and internal resistance of 0.5 C), then the equivalent intemal resistance of the
combination is

(A) 0.5 o (B) 1 o (c) l.5o , (D)2o (E) 2.5 o

o A carbon resistor is marked with the rings coloured blue, black, rcd and silver. lts
is
rcsistance in ohm , , ., 1* i .. , I

(A) 60x101 rto% (B)txto5 irc% n :.xrc6 {%
(D)3.2x101 !5% (E) 45xt01+s%

10. A conductor of length 20 cm carrying a curent of 5A' is placed at an angle of 30o to
the extemal magnetic field of0.5 T. The.force acting on it is

(A) 0.5 N (B) 5 N (c) 0.25 N (D) 2.5 N (E) 0.125 N

Space for rough work

6f
9 ,/,tl]/l\I -'\\ /rl - .')
ltlrtsr-
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_lr ,: ah 11'
\'ta,
.?--l'f , ts
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ri'
pf F-

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- _; 1 '.-
-'z\ )r 1";yQ't1
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Phy-Chy-I-A3/202 I
lP.r.o.

11. A cunetrt calr).ing coil placed in a magnetic field B experiences a torque r. Ifo is the
angle between the rormal trothe plane of the coil and field B and q is the nux
[nked
with rhe coil, then

(A) t is minimum for d: 9Qo @) t and q are maximum fo( d = 0.
(C) 9 is maximum for 0= 90" @) t and g are zero for d=9Q.
fJE))t is zero and q is maximum for g = 0.
\-/

12. In Cyclotron, the frequency of revolution ofthe charged particle in a magnetic field is
independent of

(A) ismass
c enerS,
((B) its (C) oscillatory frequency
fD) magneric field [) its charge
13. The hard ferromagnetic material among the following is
(A) gadolinium (B) iron (C) cobalt (E) trickel

Spac for rough work
@"^*

Phy-Chy-l-A3/2021

14. If B" is the magnetic induction at the ceflte ofa circular coit carrying curreflt, then
the magnetic induction at a poitrt oo the axis of the coil at a dista[ce equal to the
radius of the coil is

(u)&
') Gt lL Dt+ (E) A
. // 2,12 4 J2 8

15. If air core is replaced by an iron core in an inductor, its self-inductance is increased
tom 0.02 mH to 4p$. The relative permeabiliry of iron is
(A) 5000 (92000 (c) 200 (D) 500 (E) 400

16, Among vadous circuits coDstructed with rcsistor _R, inductor _L and capacitor C, the
cicuit that gives maximum power dissipation is
(A) purely inductive circuit (B) puely capacitive circilit

/ (C) purely resistive circuit @) l-C series circuit
(E) C-X sedes circuit

17. Eddy curreots are not used in the applicalion of
(A) itrduction tumace
fA thermal generators
(C) electoma$etic damping (D) electric power meters
(E) ma$etic bmking in hains

18. The total intensity of earth's magnetic field at the poles is 7 units. Its value at the I
equator is t2

(A) 7J2 units (B) 15 units (C) 7 unirs 1
aD):= units (E) 14 mits

Space for rough work

Phy-ChyJ-Al/202 I fP.T.O.

19. Electlomagtretic waves against their detection devices are matched below. The
mismatch is
(A) Gamma Iays Ionization chamber

(B) Miclowaves Poi t cootact diode
(C) X - rays @) Ph6to$aphic fiLr
tJltraviolet rays
Themopiles
(E) Inf:ared mys
Bolometer

20. In an electromagnetic wave, the oscillatiug electric aoil'magnetic field vectors
oriented in
(A) mutuauy peryetrdicular directions with a phase difference of z/2

(B) the same direction and in the same phase
(C) mutually peryendicular directions with a phase difference of z
@) the same direction with a phase difference of z/2

phase
@) mutually peryendicular directions- and are in

21. Frcstrel distatrce for an aperturo of size a illuminated by a parallel beam of light of
@)* @) ).a (c) a21, @+
wavelength zl deciding the validity ofruy optics is (E) o'1'

cm- Ifwater is
22. The apparctrt depth ofa needle lying in a water beaker is found to be 9 of
replaced by a liquid of refractive index 1.5, then the appareDt depth needle will

be 1p ofwater is 4/3)
(C) 12 cm (D) 7 cm (E) 8 cm
(A) 10 cm @)9cm
space for rough wo*

Phy-Chy-I-A3/202 I

An object is placed at l0 cm iI ftont of a concave mirror. If the image is at 20 cm
,,1

from the mifior otr the same side of the object, then the magnification ploduced by the
lnllror 15
(A) 3 (B) -0.5 (c) -2 (D) 0.33 (E) -1

24. In Yourg's double-slit experiment, two different lightp,beamsp2ofrespectively.
wavelengths
If
,,1, and 12 produce interfereoce pattem with batrd widths and

the tio between B, and p, is 3 : 2, then the ratio between ,! and 22 is
(A)3:1 @) l:3 (c)2:3 @)3:2 (E)4:5

25. If d, is the polarizing angle for a glass plate of refractive index p and critical angle
0",thelr

(A) 0p = 0c (B)tan0r.sin0" =l (c) epec =r

P) tanqp = sinec (E) tanep sin0c = p

26. Two mate.ials I and B having respective work fluctions 3 eV and 4 eV are emitting
photoelectrons of same maximum kinetic energy of 1eV. 1f the wavelength of i'cident
light otr I is 500 trm, then that of light incident on B is

(A) a00 nm (B) 300 nm (C) 3s0 nm (D) 600 nm (E) 250 nm
Space for rough work

Q.=utt 1 e:i
-
\ I( f- 'u,\./
,a
4, ,7oN \
4"
I
t I

v$
-14 -

\,1,1 , -lL - -tt) - t
t li/

Phy-Chy-I-A3/202 1 lP.T.O.

27. If the mometrtum of atr a -particle is Italf that of a prcton, then the Etio berween the
wavelengths oftheir de-Brcglie waves is

(A)1:2 (B)4:l (C)l:4 @)l:l (E)2: I

28. Dwing p- decay of a 14@qri$! element therc is an increase in its

(A) massnumber '": (B) neutron rumber (C) electron number
(D) proton numbei ' @) atomic weight

,o 1018 fissions per secood is required for producing power of 300 MW in a nuclear
power station. To increaie the power outi?ut to 360 MW the additional lumber of
fissions required per second is

(A)2x10'3 (B) 5x10'3 (C) 5xi0'7 @) 6xl0r? @)2x10'?

30. The ratio ofthe total eflergy E oftle elecron to its khetic eoergy ,( in hydrogen atom
is

(A) I {B)
'2 I (c)2 (D) -1 (") -i
Space for rough work

r
l' q/
fw '4f"{an.4
I hrJ
l-\
l( 7,
rJ ?-
i(,?
-T'//r.+"
1
1,'

Phy-Chyl-A3/2021 10

31, If the mass numbers oftwo nuclei are in the mtio 3 : 2, then the mtio oftheir nuclear
densities is :

(A) 3V3:2V3 (B)213 )13 (C)2:3 (D)t:t (E)3:2
32. ln p-t)?e semiconducrors
(A) holes are minority carriers
(B) the vacancy of electron is a hole with negative charge
(C) the impudty element added is donor q?e

(D) for every petrtavalent impurity atom added aII extra hole is geated

(E) the electron will move Aom otre hole to another hole constituting a flow of current

33. In a CB mode of a tr-aosistor the curent through the emitter is 6 mA. If the current
gain ofthe traDsistor is 0.95 thetr its base curent is

(A) 0.2 mA
(B) 0.3 mA (C) 0.5 mA (D) 0.4 mA (E) 0.8 mA

34. The compound semiconductor used for making LEDS ofdiffercnt colours is
(A) Gallium Arsenide Phosphide (B) Indium Arseride Phosphide
(C) Indium Arsenide - Selenide (D) Gallium Arsenide - Setenide
(E) Scandiwn Arsenide Phosphide

Space for rough work

Phy-Chy-I-A3/2021 ll [P.T.O.

35. A tlansistor amplifier along with a tank'circuit with positive feedback $rill act as

(A) power amplifier @) voltage amplifier (C) firll wave rectifier
(D) hallwave rcctifier @) oscillator

36. Irt a transmifter the audio signal of frequeacy ar- is modulated by the carier
ar. and the band pass frlter in it rejects the frequeocies

(A) a"atda^ (B) a" - at^and- o4 + al^ (C) co^and,2@"
P) @. - co- a'].d, ac (E) co. + at^atda.

37. Pick out the INCORRECT statement from the.following

(A) Speech signal requires a bandwidth of2800 Hz
(B) The approxtnate bandwidth to transmit music is 20 kIIz
(C) The bandwidrh ofvideo signals required to hammit pictures is 4.2 Mliz

(D) The bandwidth usually allocated to transmit TV signals is 6 MIIz
(E) Digital signals arc usual[y in the folm of sine waves space for mugh work

i

I
I

I
I
I Phy-Ciy-I-A3l202t t2

t\
l
i

38. A physical quantity I on multiplication with velocity results in another quantiq/ B. If
the quantity B is energy, then the quantity,4 is

(A) mass (B) momentum (C) force @) acceleration (E) power
39. Ifthe percentage erro6 in the measuements of mass, length ard tlrne are lVo,2%o aILd,
3% respectively, then the maximum permissible erlor in the measurement of the
accelemtion ofa particle is
(A) 8% (B) e% (c) 60/0 (D) 10o/o (E) 2%

The radius ofa circular plate is 1.05 m. Its area (in m2) up to cor:rect significant
figures is
(A) 3.4',7 (B) 3.47s (C) 3.46'7. (D) 3.82 (E) 3.825

41. The velocity ofa moving particle at afly instant is ;+j. The magnitude and direction
ofthe velocity ofthe particle are

(A) 2 uois and 45'with fie r-axis
(B) 2 units and 30' with rhe z-axis

(C) V2 units and 45o wirh the x-axis
{D) \E units and 60'with they-axis
(E) 2 units and 60' with rhe r-axis

a' tv1

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--'''' 1.ut+ 2_4 ! o-+- )-
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1 +-l{-{
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Phy-Chy-I-A3/2021 ,..{j( t3 Yrll - V.r.O.
'! - t
t2

-&t

A hammer is dropped itrto a mine. Its velocities at deptbs d, 2d and 3d are in the ratio
(A) 1:2:3 @)r:Jf:JJ (C)l:4:9 @)6:3:2 @)l:l:
&,
43. The stopping distance ofa moving vehicle is proportioml to the

F',*:( (A) initial velocity ' (B) cube ofthe initial velocity
(C) square of the initid{b'leily (D) cube root ofthe initial velocity
[l' (E) square root ofthe initial velocity

agr When a body starts ftom rcst and moves wiih a constant acceleration, the velocity-
tirne gaph for its motioo is

(A) (B)

I.-
(c)

vl
i1
N
l\
A
(D)

>-
(E)
I

I

t
45. A wooden block of mass 10 kg isis moving with an acceleratioa of 3ms-'ol a rough
0.3r then the applied force on it is (e f Ons"
floor. Ifthe coelficient of friction = )
(A) l0 N
(B) 30 N (c) 80 N (D) 60 N (E) 65 N

SDace for rough work
vur4 a- \A
. ) w,lo\
V' <"?lr " ^^,'"r^, ^, 3,r?
lL"^uL1?Lro, tr9, ,3
L M. u.3
u,,. q- z.a - &,tb
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Phy-Chy-l-13D02l ttz'L
- '4i'

F'z?L ,'/ , c# 114
zl1{ Y 1 r\.

{6. Which one ofthe following statement is INCORRECT?

(A) The state of rest or uniform linear motion both imply zero acceleration.

(B) A net force is needed to keep a body in uniform motion.
(C) Inertia means resistance to chaflge.

(D) The rate ofchange ofmomentum is proportional to the applied force.

(E) Momentum is a vector quantity.

47. on,^\ -(4!\ (B)mu
'\dt belt moving
' a' conveyor \cl+11,
'-'\at,, )l
p\,(+)
)
lalls at a constant
I .* (E) rf+l
' , *n.."
[4]
\drm\dr
) with a speed sand dt
) )
required to maintain the speed ofthe belt is
48. aArea
is the mass of sand. The extra force
uoder the force-time gaph gives the change in 'O ,,
(A) velocity (B) acceleratioo 'X
(C) linear momertum (D) angular momeltum

{ E) impulsive force

49. When a metal spring is elongated within its elastic limit ,-1

(A) rvork is done by the spring (B) potertial erergy is storcd in it
(C) its potertial energy is lost (D) its total eneryy rcmains constant

@) its kinetic energy is increased

50. The instantatreous power in terms of force F and instantaneous velocity v is
(A) P=F.t (B) P=F.v (C) P=F.v-' (D) P=F.v-'z @)P=F.v'r-'
. Space for rough worU . r
-,

?=rt 'l'"'*.
Y.r, I r" l,
t'tN"'

Phy-ChyJ-A3/2021 t5 lP.T.O.

51. A ball with 103J ofkinetio.ener,gy coflides with a.hodzontally mounted spring. If
maximum compression gf;ttie. spring is 50 cm, then the spring constatrt ofthe spring
(A) 2 x 103 Nm-r "rij: ill.r (B) 6 x 10r Nm-t (c)8x 103 Nm-'
(D)5 x lorNm' (g):x lo3Ntror
. ,1: or la^n :
52. An object released ftofii'C-eirthin heightl, fioo the ground rebounds to a height
after striking the ground. Tho ftaction ofthe enerry lost by it is

,o'
'4 ! ''4:
rB) (cl'2! @)+ rrl;
53. A solid metal ring rind a disc of same radius and mass are rotating about
diameters with same angular frequency. The ratio of their
respective
kinetic energy values is

(A) l: I (B)1:2 (c)2: 1 @) 1:4 (E)4: I

54. The X and Y coordinates of the three particles of masses ,1, 2m ard 3m
respectively (0,0), 0,0)and (-2,0). The x-coorditrate of the centre ofmass of

system is

,o,! rB)? (o-: @)-1 G)lt,
J3
55. Radius of gyration of a solid cylinder of radius R and length Z about its long axis
slmmety is
(A) x .,# G){2R '2 J:
.D) E\ 2R

Space for mugh work

o, \,'t
^,*i449
-|A 2w\ 1p <\\(? 2/t 3.4
|ryt:y"'
A"a s^
6.,or

"\ Z,

Phy-Chy-I-A3/202 I ^
(u\2
^/)
16

5q.,\ When no extemal torque acts on a rotating system,
(A) angular momentum ofthe system is not conserved
(B) its rotational kinetic energr is conserved
(C) its rotational kinetic eoei.ry i{ indepetrdent ofmoment offuIertia
(D) irs rotational kjnetic eoergy is directly proponional to momeot of inenia

(E) its rotational kinetic energy is inve$ely proportional to moment of inertia

If 7 be the time period of a planet around the Sun and d is its mean distalce from
the Sun, then accorditrg to Kepler's thfud law
@)T ct d1 (CST? ,r d\ P) T'2 a d (E) T2 ct d-3

(A) T cLd
Ifthe earth shrinks to half of its present size and its mass reduces to halfofits actual
mass, then the acceleratiotr due to gravityG) on its surface will be

(A) 4c (B) g (c) 2s ror (E) 3e
2

59. When two idetrtical spheres each ofradius r are kept iA contact with each othet thetr
tbe force of attractiotr between the two spheres is proportional to
(A) (B),' (c) ,u (D),-, (E),-
" ry

Wilt tLe increase of tempemture t
F
(A) surface tension ofliquid increases i:

@) viscosity ofgases decreases l
(C) viscosity ofliquids increases
(D) both the surface tension and viscosity of liquids increase
(E) both the surface tension and viscosity of liquid decrease
Spac for rough work

t
1L c-*
r{t\,
z
. Gu
-.7
llr 4-
?_
't
f. Gvly .y'?-
G\ .-,' A1r,\-'-
-z- I
L-nL
Phy-Chy-I-A3/2021 17 [P.r.o.

t

61- The TRUE statement is
(A) Young's modulus of a wire depends on its length
(B) The uoit ofYoung's modulus is Nm-r
(C) DimensioMl foflfifilfi tifstress is same as that offorce
(D) The unit of straii id fim-2
(E) Compressibitity is the reciprocal ofbulk modulus

Wtren a body is strained enrgl stored per unit volume is (F = Youtrg's modulus)

(saess) Yxstrain (c) {' sr'e.!s I
(A) (B)
Y 2 )Y
1/,srres,s\
{D1 Y x(srrain)z (E) -t_l
2lY )
Accoding to equation of continuity when a liquid flows thrcugh a tube of variable
cross section a with variable velocif v, the quafltity that remains coNtant is
a'
(A) av2 (B) a2tt (c)av (r>); 1B)

II
(
64. Two thermally insulated identical vessels I a1ld.B are connected through a stopcock'
I
I contains a gas at STP and B is completely evacuated. If the stopcock is suddeoly
opened then
C
I (A) tempe.ature is halved

. (B) intemal energy ofthe gas is halved
(C) intemal energy ofth gas and prcssure are halved

@) temperahre and intemal energy of the gas remain the same
(E) pressure alld internal energy ofthe gas remain the same
Space for rough work

r!;' u- c ,.q'1
ncL+tu
Xr'l1JrL1-Y'
El --- itl 4" t\r
L'G r!4P V, st:Y4*n
W ftqr- ' <^'
d\'
Nt o.\n r '-
- 4/r lo

Phy-Chy-I-A312021 t8

65. A prccess in which therc is no flow of heat betweeo the systeii and surrouudirgs is
a/at
(A) adiabatic process @) cyclic process
(C) isobaricprocess @) isochoic process
(E) isothermal process,

66. Wllen the tempetature of the source ofa Camot etrgine is at 400 Iq its ef6ciency tois
25%. The requircd increase in temperature of the source to increase the elficiency
50% is

(A) 8o0K (B) 600K (c) l00K (D) 400 K (E)200K
.
67. When an ideal diatomic gas is heated at constaat pressue, ftaction of heat enerry
supplied that increases the internal energy ofthe gas is

.1',t51 (D);
(A)
; @)
, rc); (E);

68. The ratio ofthe kinetic energ)r values of4g ofhydrogen (92) to 7g ofnitrogen (N2) at
room temprature is NO Answer
(A)4: I @)l:4 (c)4:7 @)7:a G)l:l
ff
space for rough work
/r4 n, n
4

-1^t. ?

PLy-Chy-I-13/2021 19 [P.T.O.

;

-
69.
1!M d3:4rr rt arrd acceleration due to $avity g, will have armosphere only.if
r.z.s. speed of air molecules is less tha[

(A) 1.414,[sR
e 2.[A 1o) 3.14\Gi @z:75\[sR
70.
llP^trl":,9:-::lryon
surface-of the moon is 6:1, then d:" to.graviry on the surface of earth to rM on the
the ratii of th" p".ioa. of u
surfaces is
.,,1'.i'
ffif"-;#Or_*;it:;
(A)l:l (B)l:6 :3
(C) I @) t:..6 6) l:16
71. The velocity ofa harsverse_wave propagating
on a saetched stdng reFGscGd by the
equadon, , = O.ssinl ar +1, I i. r*t-ere r,and;z are in mehes artd / ia mds)
\2 3)
(A)0.5ms.l (B) 1.0 Es-r (C)2ms-r (D) 3ms-r @ lsnsj
The kinetic energy of a particle of mass z executing
linear simple hrr i. Eotion
with angutar velocity a and amplitude a is mara,
.! at a d.jstance of
bom the mean positioo. '
a
(A)
o Bt!
'2 (c)
i (D) a G';
Space for rough work

3, **i !- s

3*\ @ W,
It'

Phy-Chy-I-A3/2021

. t (a.l)
73, The reagelt that is used to coovert but-2-)'ne to'tans but-2-ene is
(A) HrlPd/C (B) NaBHI (C) SnfiCl

(D) Naniquid NH3 (E) Zn-HelHCl

14. Compound 'l'is obtained by the reaction ofbeltyl chloride with magnesium metal
in dry ether followed by heatment with wate. What is the compound
"4'?
(A) Toluene (B) Benzyl alcohol (C) Phenol

(D) Benzene @) Benzaldehyde

The correct ircreasing order ofboililg points of the following compounds is
(A) CH,Br, < CHrBr < CHBq < CH,CI
(B) CH,BI, < CHBq < CH3Br < CHrCI
(C) CH,CI < CH,Br < CH,Br, < CHBI.
(D) CH,CI < CHBr, < CH,Br < CH,Br,
(E) CHBi, < CH,B!, < CH,BI < CH,CI
76. Compoutrds 'A','B' and 'C' have the same molecular formula CrHtO Compound
'A' and 'B' liberate hydrogen gas with sodium metal. When teated with sodium
hydroxide, compound 'B' alone dissolves. Compound 'C' is inert towards both
sodium metal and sodium hydroxide. Compounds 'l',
'B' and 'C' are rcspectively
(A) Cresol, benzyl alcohol and anisole
(B) Benzyl alcohol, cresol and anisole
(C) Benzyl alcohol, arisole and cresol

(D) Cresol, anisole and benzyl alcohol
(E) Anisole, cresol and ben-zyl alcohol
Space for rough wotk 9D
d-L
't)

Phy-Chy-l-A3D02l 2t [P.T.O.

77. The suitable Grignard reagent used fdr the preparatioo
of2_methylpropal-l_ot using
methanal is
(A) CHj-CHr-CH,MgBr (B) CH,-CH,{H,-CH,MgBT
(c) crr3 -cH (crt ) -cH,tvfgBr (D) (cr,),c-r,rgrr
@) cI!-cH(cII3)aviBH:: .,
.::,
78. Isgyrol/benzene (cunene) is oxidized in the presence of
air to give compowd
which on hydrolysis in the presence of acids gives .f _d
Compounds .-I, , I. and .? are rcspectively "o_poiod"
(A) benzyt atcohol beozal.dehyde, ethanol
@) cumene hydroperoxide, phetrol, acetaldehyde
(C) cumerc hydroperoxide, benzaldehyde, acetone
(D) cumene hy&operoxide, phenol, acetofle
(E) cumerc hydroperoxide, benzaldehyde, acetaldehyde
Space for rougL work

Phy-Chy-I-A3/202 I 22

I
L

I

A research scholar retumed to the laboratory after the lock down due to Covid_19.
He kept acetone, benzaldehyde, acetaldehyde and diethyl ketone irl four
different
bottles. The bottles cortained only the label as p,
e, i and S. He forgot which bottle
contained which compound. Compounds p and _R orry underwent iodoform
test.
Compound R alone gave reddish brown piecipitate with Fehling,s reagent.
Compounds Q and R alone underwent Tollen,s test. Compound S did not
ans*er any
ofthe above tests.
Identiry the compounds P, Q, rt and S.
(A) P-diethyl ketone; Q-benzaldehyde; it-acetaldehyde; S-acetore
(B) P-acetone; O-benzaldehyde; R-acetaldehyde; S-diethyl ketone
(C) P-acetone; Q-acetaldehyde: R-benzaldehyde;
^S-diethyl ketone
(D) P-acetaldehyde; O-acetone; R-diethyl ketone;,S-benzaldehyde
(E) P-berualdehyde; O-diethyl ketone; R-acetonej,s_acetaldehyde

80. The increasing order ofacid strength ofthe following carboxylic acids is
(A) ClcH,-cH,-cooH < clcH,cooH < Nc_CH,COOH <CHCI,COOH
(B) ClcH,-cooH < NC - CH2COOH < CICH,CH,COOH < CHC12COOH
(c) clcH, -cH,-cooH < cHCt,_COOH < CICH,-COOH < NC-CH,-COOH
(D) NC-CH,-COOH < Cl_CH,COOH < CH_CI,COOH < CI_CHTCH,COOH
(E) CICH,CH,-COOH < CHCITCOOH < CICH,COOH < NC-CH,COOH

81. Which one ofthe following is not correct with respect to properties ofamines?
(A) pK6 ofaniline is more than that ofmethylamine.
(B) Ethylamine is soluble ir water whereas aniline is not.
(C) Ethanamide on reaction with Br2 ard NaOH gives ethylamine.
(D) Ethylamine reacts with nihous acid to give ethanol.
(E) Aniline does not undergo Friedel-Cmfts reaction.
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Phy-Chy-I-A3/202 I 23
[P.r.o.

82, The iocreashg order of exteut of H-bonding of the alkyl ammonium
ions, RNHI,
R2\'Hr, R.NH* in water is
(A) R3NH+ < RrNH; < RNfii (B) R3NH+ < RNHI <RrNH;
(c) RrNH; < RNHi < R3NH+ (D) RNHI < RrNH; < R3NH*
(E) RNHi < R3N'H* < RrNH;

The conversion of benzene diazonium chloride l.o bromobenzeDe bv trearins
HBr ir the preseoce ofcopper powder is called
(A) Sandrneyer reaction (B) Gattermann rcaction
(C) Wultz rcactior (D) Hoftnann reaction
@) Gabriel qrnthesis

84. Which one ofthe following statemeots is TRUE with regard to glucose?

(A) It gives Schif,s test
(B) It forms additiotr product with NaHSO3
(C) Its pentaacetate does not react v/ith NH2OH
(D) It does not undergo mutarotation
(E) p- form ofglucose is obtained by crystallisation from conc. solution of glucose
at 303K

Fibrous
(A) protein preseot in muscles is
keratin
@) albumin (C) insutin (D) myositr @) hisidine
The drug used to inhibit the erzynes which catalyse the degadation of
noradrenaline is
(A) phenelzine (B) prcntosil (C) cimetidine
(D) terfetradine @) chloramphenicot

87. The gas which is the major contributor to globat warming is
(A) No, (B) COz (c) so, (D) o, (E) N,o

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Phy-Chy-[-1J/2021

88. A cooking gas conuins ca$on aod hy&ogen only. A volume of ll.2 L oftbis gas
is
found to weigh 22 g at STp. Then the molecular formula ofthe gas
is
(A) CaHs @)crH, (C) CrH4 @) c:H" (E)crHr
89- The number of electrons in an atom tbat rnay have the quanhrm numbers
,=3aod
ms=+/1ts

(A) 32 (B) e (c) 18 @) 16 (E) 8

'No two electrotrs itr an atom can have the same set of four quantum numbers.,,This
is known as

(A) Hund's rule @) pauli,s exclusion principle (C) Aufbau principle
(D) Heisenberg's principle (E) Fajar,s rule

9l- The first ionisation enthalpy is the least in

(A) Germanium (B) Antimory (C) Tellurium
(D) Arsenic (E) Bismuth

92, Predict in which of the following, enhopy decreases:
(A) A liquid crystallizes into a solid.
(B) Temperatue ofa crystaltine solid is raised from OK to 115K.
(C) 2NaHCOr(s) -,, Na2COr(s)
- CO;(g) - H2O(g )
(D) Hr(s) + 2H(c)
(E) 2SOr(g) + 2SOr(s)+O2(c)

93. In which one ofthe following, .!p, hybridisation is itrvolved in the
central atom?
(A) NH: (B) BC13 (C) ClFr (D pcl3 (E) pH3

.
': t"
Space for rough wo.k

_t + A?c,H ,-,--s rr.z.
\23-w1.-ar
"5-I
.\
,.,
'tt
1- -g- j
lt=3
l- 1, z,-t o , *fu,w lo
4'.k.1,
Phy-Chy-I-A312021 25 {v^ t tF.r,d.

94, I[ which one ofthe following molecules, the centBl atom has
expanded octet?
(A) Sulphur dichloride (B) Boror trichloride
(C) Nitrogen dioxide
(D) Ozone (E) Sulphuric acid

95- A cycle tube will burst ifthe volume ofair inside exceeds
lL at the
Ifat I bar presswe the air occupies 500 mL, tt ,p to *f,ut pr"i.*"room temDerature.
*
expanded at the same tempemture? """'j""rU" U"
(A) 2 bar (B) 1.5 bar (C) 0.s bar (D) 0.002 bar (E) 1.2 bar
96. The ratio of the actual molar volume ofa gas to the ideal molar volume is
the gas.
(A) co-volume (B) van dbr Waals factor ,a,
(C) critical volume (D) molax gas constant
(E) compressibility factor

97. Enthalpy change is always negative for which one
ofthe following processes?
(A) Enthalpy of ionisation (B) Enthalpy of sublimation
(C) Enthalpy of vapourisation (D) Enthalpy of tusion
(E) Enthalpy of combustion

98. The enthalpy change for the eyaporatioil of a liquid
at its boiling point 127oC is
+40.32 kJmol-' . What is the value of internal energy
change for the above process at
127oC? (R = 8.3 JKhorr)
(A) -37.0 kJmol ' (B) +43.0 kJmol 1

(C) +37.0 kJrnol-' (D) -43.0 kJmol-l
(E) +43.64 kJmol-'

99. In which one ofthe following equilibriaAn* value is zero?
(A) 2Noc(s) 2No(e) + Cl:(g) (B) NiG) + 4co(g) e N(Co)a(g)
=
(C) Cor(s) + cG) + 2co(g) (D) Hr(g)+B1(g) 2HB(g)
(E) NrO(g) + 2NOr(g) =
Space for rough work

61

J aL Bt J0 I.. l/rl Icl-
\r
+ hrt
v{ :\:a 'ut,
,0" , ,_ l6.@z:It)' ?

Phy-Chy-I-A312021 'vb '; i, (ht,L)'

ll ,:n'
r?,*
l?Z'-; ,.,{:1

105. For the reaction2p + e C pre , the rate of fomation of pre is 0.24 mol dm-rar
Then the rates ofdisappearance of p and
e respectively are
(A) - 0.48 mol dm-3s and - 0.48 mol dm 3sr
I

(B) - 0.24 mol dm-3tr and 3s-l
- 0.48 mol dm
(C) 0.48 mol dm-rs t and - 0.24 mol dm rs @) - 0,12 mol I
I 3s I
dm-3s and - 0.24 mol dm
(E) 0.24 mol dm 3s rand 0.12 mol dm 3s-l
106. Choose the co[ect set ofrcactions which follow first order kinetics:
(i) Thermal decomposition ofHI on gold surface.
(ii) Themal decomposition ofN2o5(g).at constant volume.
(iii) Hydrogenation of ethene.
(iv) Decomposition ofNH3 on a hot pt surface.
(v) Thermal decomposition of SOrCl2(g) at constrant volume.

(A) i, ii, iii (B) i, iii, iv

107. Which one ofthe following is true?
(A) Chemisorption is not specific in nature
(B) Physisorption is ireyeNible
I
(C) Both physisorption and chemisorption depend on the nahre of the gas
(D) Enthalpy of adsorytion is high in physisorption
@) Chemisorption inqeases with surface arca of adsorbent while iII physisorption it
' is not
Space for rough work

hi ,J

, 'i,,\0 2'
h.\0.1

Phy-ChyJ-A3/2021 28

108. W1len zinc metal is reacted with aqueous sodium hydroxide, the products fomed arc
(A) zinc hy&oxide ard oxygen only
(B) sodium zincate and oxygel o y
(C) sodium zincate, hydrogen and oxygen
(D) sodium zincate and hydrogen only
(E) sodium zincate and hydrogen oxide only

109. 'Syngas' produced from sewage is a gaseous mixture of
(A) CHr and CrH6 @) CO and H, (C) CO and CHa
(D) CS, and CO (E) CS, and CHr

110. Choose the correct choice containing true statements regaxding pcl5.
----1q PCl5 is prepared by the reaction ofwhite phosphorus with excess ofdry chlorine.
(ii) The complete hydrolysis ofpcl5gives phosphoric acid.
(iii) PC15 has square pyramidal structure in gaseous phase.
(iv) All the five bonds in pCl5 molecule are equiyalent.
(A) ii and iii (B) i and iii (C) iii and iv (D) ii and iv @) i and ii
111. Match the substances and their uses.
a) Silicones (i) Cracking of hydrccaxborc
b) Zeolites (ii) Light composite material for aircraft
c) Quartz (iii) Flux for soldering metals
d) Borax (iv) Waterproofing of fabrics
e) Boron fibres (v) Piezoelectric material
(A) a)-(iv); b)-(ii); c)-(i); d)-(v); e)-(iii)
(a) a)-(i); b)-(ii); c)-(iv); d)-(iii); e)-(v)
(C) a)-(iv); b)-(i); c)-(iii); d)-(ii); e)-(v)
(D) a)-(iii); b)-(ii); c)-(i); d)-(iv); e)-(v)
@) a)-(iv); b)-(i); c)-(v); d)-(iii); e)-(ii)
' Space for rcugh work
o
\\./
L$ #.y GrS=+ {-lqLz\DLtY-
4 <' ',,.c t

\'r*
-a
Phy-Chy-l-A3/2021 29 ati
[P.r.o.

112. Choose the wrong statemeat in the following with regard ro orthoboric acid:
(A) It can be prepared by the hydrolysis ofboroo tihalide

(B) It is not a protonic asid but acts as a Lewis acid
(C) It has a layer stsucture
fD) It is freely soluble in cold water
(E) On heatiry above 370K it forms first metabodc acid which on futher heating
yields B2O3

ll3. The magrctic momeot ofa trivalent ion ofa metal v/ith Z= 24 in aqueous solution is
(A) 3.87 BM (B) 2.84 BM (C)1.73BM (D)4.90BM (E) s.92 BM 114.
In the first rolv transitioD metals, the element that exhibits only +3 oxidation state is
(A) zitrc (B) scardium (C) nickel @) titanium @) irotr

115. The metal that has the highest melting poitrt in the first sedes oftransitiotr elements is
(A) titaniuE (B) vanadium (C) cbromium (D) non (E) manganese

116. In which one of the following complexes, the conductivity coresponds to 1:2
electrolfs in aqueous solutioE?
(A) Hexaamminecobatt(IlD chloride

@) TetraamminedichlorocobaltQtr) chloride
(C) Pentaanminechtorocobalt(ItD chlodde
(D) Triamminetriaquachromium(Ill) cbloride

@) Diammiaesilve(D dicyarcargentate(I)
Space for rough work

,\^-#!t z-zl Gqs

Phy-Chy-t-A312021 30

ll7. The complex ion formed when the film developed itr black
ard white photography
is washed with hypo solution is,

(A) [Agr(SrO3),]3- @) [Ag(sro3)rJ3- (C) tAg(Sro),13.
@) [Agz(s:o:)z]3* @) [Ag(suor):1]-.

118. Which one of the following is an ore of aluminium?
(A) Kaolinite (B) Siderite (C) Malachite (D) Calamine (E)
Haematire
\-
11S- In the estimation irf nitrogen present in an organic compound, Kjeldahl,s method
cannot be applied to
(A) aniline (B) totuidine (C) urea (D) plaidine (E) benzylamine

120. Among the following, the alkele that exhibits optical isomerism is
(A) 3-merhyl-2-pertene @) 4_inethyl 1_pentene (C)
3-methyl l_pentene
@) 2-methyl-2-pentene @) 2, 3_dimethyl 2_butere

Space for rough work

Vt^ov t\"kY$t

a ,C:U <a 'C C
n\
z: )n3t".* ( l+z
\-
-=('

2

Phy-Chy-I-A3/202t 3l