Page 1
1
FINAL JEE –MAIN EXAMINATION – JULY, 2022
(Held On Friday 29
th
July, 2022) TIME : 3 : 00 PM to 06 : 00 PM
PHYSICS
TEST PAPER WITH SOLUTION
SECTION-A
1. Two identical metallic spheres A and B when
placed at certain distance in air repel each other
with a force of F. Another identical uncharged
sphere C is first placed in contact with A and then
in contact with B and finally placed at midpoint
between spheres A and B. The force experienced
by sphere C will be :
(A) 3F/2 (B) 3F/4
(C) F (D) 2F
Official Ans. by NTA (B)
Sol. Let q
A
= q
B
= q
A B
r
2
2
Kq
F
r
?
When C is placed in contact with A, charge on A
& C will be =
q
2
Now C is placed in contact with B, charge on B &
C will be =
q
q
3q
2
24
?
?
Now,
A B
F
1
C
F
2
r
2
r
2
3q
4
3q
4
q
2
21
2
3q q
KK
42
F' F F
r
4
??
?
??
??
? ? ? .
3q
4
2
2
3Kq 3F
4 4r
?? (B)
2. Match List I with List II.
List I List II
A. Torque I. Nms
–1
B. Stress II. J kg
–1
C.
Latent
Heat III. Nm
D. Power IV. Nm
–2
Choose the correct answer from the options given
below:
(A) A-III, B-II, C-I, D-IV
(B) A-III, B-IV, C-II, D-I
(C) A-IV, B-I, C-III, D-II
(D) A-II, B-III, C-I, D-IV
Official Ans. by NTA (B)
Sol. Torque = Fr
?
? Nm
Stress =
Force
Area
N/m
2
Latent heat =
Energy
Mass
J Kg
–1
Power =
Work
Time
N ms
–1
A-III, B-IV, C-II, D-I
3. Two identical thin metal plates has charge q
1
and q
2
respectively such that q
1
> q
2
. The plates were
brought close to each other to form a parallel plate
capacitor of capacitance C. The potential
difference between them is :
(A)
? ?
12
qq
C
?
(B)
? ?
12
qq
C
?
(C)
? ?
12
qq
2C
?
(D)
? ?
12
2 q q
C
?
Official Ans. by NTA (C)
Sol. Electric field between plates
12
0
qq
E
2A
?
?
?
V = Ed =
12
0
qq
d
2A
?
?
V =
12
qq
2C
?
Page 2
1
FINAL JEE –MAIN EXAMINATION – JULY, 2022
(Held On Friday 29
th
July, 2022) TIME : 3 : 00 PM to 06 : 00 PM
PHYSICS
TEST PAPER WITH SOLUTION
SECTION-A
1. Two identical metallic spheres A and B when
placed at certain distance in air repel each other
with a force of F. Another identical uncharged
sphere C is first placed in contact with A and then
in contact with B and finally placed at midpoint
between spheres A and B. The force experienced
by sphere C will be :
(A) 3F/2 (B) 3F/4
(C) F (D) 2F
Official Ans. by NTA (B)
Sol. Let q
A
= q
B
= q
A B
r
2
2
Kq
F
r
?
When C is placed in contact with A, charge on A
& C will be =
q
2
Now C is placed in contact with B, charge on B &
C will be =
q
q
3q
2
24
?
?
Now,
A B
F
1
C
F
2
r
2
r
2
3q
4
3q
4
q
2
21
2
3q q
KK
42
F' F F
r
4
??
?
??
??
? ? ? .
3q
4
2
2
3Kq 3F
4 4r
?? (B)
2. Match List I with List II.
List I List II
A. Torque I. Nms
–1
B. Stress II. J kg
–1
C.
Latent
Heat III. Nm
D. Power IV. Nm
–2
Choose the correct answer from the options given
below:
(A) A-III, B-II, C-I, D-IV
(B) A-III, B-IV, C-II, D-I
(C) A-IV, B-I, C-III, D-II
(D) A-II, B-III, C-I, D-IV
Official Ans. by NTA (B)
Sol. Torque = Fr
?
? Nm
Stress =
Force
Area
N/m
2
Latent heat =
Energy
Mass
J Kg
–1
Power =
Work
Time
N ms
–1
A-III, B-IV, C-II, D-I
3. Two identical thin metal plates has charge q
1
and q
2
respectively such that q
1
> q
2
. The plates were
brought close to each other to form a parallel plate
capacitor of capacitance C. The potential
difference between them is :
(A)
? ?
12
qq
C
?
(B)
? ?
12
qq
C
?
(C)
? ?
12
qq
2C
?
(D)
? ?
12
2 q q
C
?
Official Ans. by NTA (C)
Sol. Electric field between plates
12
0
qq
E
2A
?
?
?
V = Ed =
12
0
qq
d
2A
?
?
V =
12
qq
2C
?
2
4. Given below are two statements: one is labelled as
Assertion A and the other is labelled as Reason R.
Assertion A: Alloys such as constantan and
manganin are used in making standard resistance
coils.
Reason R: Constantan and manganin have very
small value of temperature coefficient of
resistance.
In the light of the above statements, choose the
correct answer from the options given below.
(A) Both A and R are true and R is the correct
explanation of A.
(B) Both A and R are true but R is NOT the correct
explanation of A.
(C) A is true but R is false.
(D) A is false but R is true.
Official Ans. by NTA (A)
Sol. Theory based
5. A 1 m long wire is broken into two unequal parts
X and Y The X part of the wire is streched into
another wire W. Length of W is twice the length of
X and the resistance of W is twice that of Y. Find
the ratio of length of X and Y.
(A) 1 : 4 (B) 1 : 2
(C) 4 :1 (D) 2 : 1
Official Ans. by NTA (B)
Sol.
Y X
? 1– ?
W
2 ?
XX
YY
R
R
?
When wire is stretched to double of its length, then
resistance becomes 4 times
R
W
= 4R
X
= 2R
Y
X
Y
R 1
R2
?
X
y
1
So.
2
?
6. A wire X of length 50 cm carrying a current of 2 A
is placed parallel to a long wire Y of length 5 m.
The wire Y carries a current of 3 A. The distance
between two wires is 5 cm and currents flow in the
same direction. The force acting on the wire Y is :
X
2A 3A
5cm
Y
(A) 1.2 × 10
–5
N directed towards wire X.
(B) 1.2 × 10
–4
N directed away from wire X.
(C) 1.2 × 10
–4
N directed towards wire X.
(D) 2.4 × 10
–5
N directed towards wire X.
Official Ans. by NTA (A)
Sol. Force of interaction = I
1
?
1
B
12
0 1 2
1
II
2r
?
?
?
7
2
4 10 6 0.5
2 5 10
?
?
? ? ? ?
?
? ? ?
= 1.2 × 10
–5
towards X
7. A juggler throws balls vertically upwards with
same initial velocity in air. When the first ball
reaches its highest position, he throws the next
ball. Assuming the juggler throws n balls per
second, the maximum height the balls can reach is
(A) g/2n (B) g/n
(C) 2gn (D) g/2n
2
Official Ans. by NTA (D)
Sol. Time taken by ball to reach highest point =
u
g
Frequency of throw =
g
n
u
?
g
u
n
??
2
2
max
g
u n
H
2g 2g
??
??
??
??
2
g
2n
Page 3
1
FINAL JEE –MAIN EXAMINATION – JULY, 2022
(Held On Friday 29
th
July, 2022) TIME : 3 : 00 PM to 06 : 00 PM
PHYSICS
TEST PAPER WITH SOLUTION
SECTION-A
1. Two identical metallic spheres A and B when
placed at certain distance in air repel each other
with a force of F. Another identical uncharged
sphere C is first placed in contact with A and then
in contact with B and finally placed at midpoint
between spheres A and B. The force experienced
by sphere C will be :
(A) 3F/2 (B) 3F/4
(C) F (D) 2F
Official Ans. by NTA (B)
Sol. Let q
A
= q
B
= q
A B
r
2
2
Kq
F
r
?
When C is placed in contact with A, charge on A
& C will be =
q
2
Now C is placed in contact with B, charge on B &
C will be =
q
q
3q
2
24
?
?
Now,
A B
F
1
C
F
2
r
2
r
2
3q
4
3q
4
q
2
21
2
3q q
KK
42
F' F F
r
4
??
?
??
??
? ? ? .
3q
4
2
2
3Kq 3F
4 4r
?? (B)
2. Match List I with List II.
List I List II
A. Torque I. Nms
–1
B. Stress II. J kg
–1
C.
Latent
Heat III. Nm
D. Power IV. Nm
–2
Choose the correct answer from the options given
below:
(A) A-III, B-II, C-I, D-IV
(B) A-III, B-IV, C-II, D-I
(C) A-IV, B-I, C-III, D-II
(D) A-II, B-III, C-I, D-IV
Official Ans. by NTA (B)
Sol. Torque = Fr
?
? Nm
Stress =
Force
Area
N/m
2
Latent heat =
Energy
Mass
J Kg
–1
Power =
Work
Time
N ms
–1
A-III, B-IV, C-II, D-I
3. Two identical thin metal plates has charge q
1
and q
2
respectively such that q
1
> q
2
. The plates were
brought close to each other to form a parallel plate
capacitor of capacitance C. The potential
difference between them is :
(A)
? ?
12
qq
C
?
(B)
? ?
12
qq
C
?
(C)
? ?
12
qq
2C
?
(D)
? ?
12
2 q q
C
?
Official Ans. by NTA (C)
Sol. Electric field between plates
12
0
qq
E
2A
?
?
?
V = Ed =
12
0
qq
d
2A
?
?
V =
12
qq
2C
?
2
4. Given below are two statements: one is labelled as
Assertion A and the other is labelled as Reason R.
Assertion A: Alloys such as constantan and
manganin are used in making standard resistance
coils.
Reason R: Constantan and manganin have very
small value of temperature coefficient of
resistance.
In the light of the above statements, choose the
correct answer from the options given below.
(A) Both A and R are true and R is the correct
explanation of A.
(B) Both A and R are true but R is NOT the correct
explanation of A.
(C) A is true but R is false.
(D) A is false but R is true.
Official Ans. by NTA (A)
Sol. Theory based
5. A 1 m long wire is broken into two unequal parts
X and Y The X part of the wire is streched into
another wire W. Length of W is twice the length of
X and the resistance of W is twice that of Y. Find
the ratio of length of X and Y.
(A) 1 : 4 (B) 1 : 2
(C) 4 :1 (D) 2 : 1
Official Ans. by NTA (B)
Sol.
Y X
? 1– ?
W
2 ?
XX
YY
R
R
?
When wire is stretched to double of its length, then
resistance becomes 4 times
R
W
= 4R
X
= 2R
Y
X
Y
R 1
R2
?
X
y
1
So.
2
?
6. A wire X of length 50 cm carrying a current of 2 A
is placed parallel to a long wire Y of length 5 m.
The wire Y carries a current of 3 A. The distance
between two wires is 5 cm and currents flow in the
same direction. The force acting on the wire Y is :
X
2A 3A
5cm
Y
(A) 1.2 × 10
–5
N directed towards wire X.
(B) 1.2 × 10
–4
N directed away from wire X.
(C) 1.2 × 10
–4
N directed towards wire X.
(D) 2.4 × 10
–5
N directed towards wire X.
Official Ans. by NTA (A)
Sol. Force of interaction = I
1
?
1
B
12
0 1 2
1
II
2r
?
?
?
7
2
4 10 6 0.5
2 5 10
?
?
? ? ? ?
?
? ? ?
= 1.2 × 10
–5
towards X
7. A juggler throws balls vertically upwards with
same initial velocity in air. When the first ball
reaches its highest position, he throws the next
ball. Assuming the juggler throws n balls per
second, the maximum height the balls can reach is
(A) g/2n (B) g/n
(C) 2gn (D) g/2n
2
Official Ans. by NTA (D)
Sol. Time taken by ball to reach highest point =
u
g
Frequency of throw =
g
n
u
?
g
u
n
??
2
2
max
g
u n
H
2g 2g
??
??
??
??
2
g
2n
3
8. A circuit element X when connected to an a.c.
supply of peak voltage 100 V gives a peak current
of 5 A which is in phase with the voltage. A
second element Y when connected to the same a.c.
supply also gives the same value of peak current
which lags behind the voltage by
2
?
. If X and Y
are connected in series to the same supply, what
will be the rms value of the current in ampere ?
(A)
10
2
(B)
5
2
(C) 52 (D)
5
2
Official Ans. by NTA (D)
Sol. Element X should be resistive with R = 20 ?
Element Y should be inductive with X
L
= 20 ? ?
When X and Y are connector in series
22
L
Z X R 20 2 ? ? ?
0
0
E 100 5
IA
Z 20 2 2
? ? ?
0
rms
I 5
IA
2 2
??
9. An unpolarised light beam of intensity 2I
0
is
passed through a polaroid P and then through
another polaroid Q which is oriented in such a way
that its passing axis makes an angle of 30° relative
to that of P. The intensity of the emergent light is
(A)
0
I
4
(B)
0
I
2
(C)
0
3I
4
(D)
0
3I
2
Official Ans. by NTA (C)
Sol.
I
1
I
2
2I
0
? ?
1 0 0
1
I 2I I
2
??
I
2
= I
1
cos
2
30º
0
0
3I 3
I.
44
??
10. An ? particle and a proton are accelerated from
rest through the same potential difference. The
ratio of linear momenta acquired by above two
particals will be :
(A) 2 :1 (B) 2 2 :1
(C) 4 2 : 1 (D) 8 : 1
Official Ans. by NTA (B)
Sol. p 2mE 2mqV ??
p p p
p m q 42
p m q 1 1
? ? ?
? ? ?
22
1
?
11. Read the following statements:
(A) Volume of the nucleus is directly proportional
to the mass number.
(B) Volume of the nucleus is independent of mass
number.
(C) Density of the nucleus is directly proportional
to the mass number.
(D) Density of the nucleus is directly proportional
to the cube root of the mass number.
(E) Density of the nucleus is independent of the
mass number.
Choose the correct option from the following
options.
(A) (A) and (D) only. (B) (A) and (E) only.
(C) (B) and (E) only. (D) (A) and (C) only
Official Ans. by NTA (B)
Sol. R ? A
1/3
3
4
V R A
3
? ? ?
Mass ? A
So density is independent of A.
Page 4
1
FINAL JEE –MAIN EXAMINATION – JULY, 2022
(Held On Friday 29
th
July, 2022) TIME : 3 : 00 PM to 06 : 00 PM
PHYSICS
TEST PAPER WITH SOLUTION
SECTION-A
1. Two identical metallic spheres A and B when
placed at certain distance in air repel each other
with a force of F. Another identical uncharged
sphere C is first placed in contact with A and then
in contact with B and finally placed at midpoint
between spheres A and B. The force experienced
by sphere C will be :
(A) 3F/2 (B) 3F/4
(C) F (D) 2F
Official Ans. by NTA (B)
Sol. Let q
A
= q
B
= q
A B
r
2
2
Kq
F
r
?
When C is placed in contact with A, charge on A
& C will be =
q
2
Now C is placed in contact with B, charge on B &
C will be =
q
q
3q
2
24
?
?
Now,
A B
F
1
C
F
2
r
2
r
2
3q
4
3q
4
q
2
21
2
3q q
KK
42
F' F F
r
4
??
?
??
??
? ? ? .
3q
4
2
2
3Kq 3F
4 4r
?? (B)
2. Match List I with List II.
List I List II
A. Torque I. Nms
–1
B. Stress II. J kg
–1
C.
Latent
Heat III. Nm
D. Power IV. Nm
–2
Choose the correct answer from the options given
below:
(A) A-III, B-II, C-I, D-IV
(B) A-III, B-IV, C-II, D-I
(C) A-IV, B-I, C-III, D-II
(D) A-II, B-III, C-I, D-IV
Official Ans. by NTA (B)
Sol. Torque = Fr
?
? Nm
Stress =
Force
Area
N/m
2
Latent heat =
Energy
Mass
J Kg
–1
Power =
Work
Time
N ms
–1
A-III, B-IV, C-II, D-I
3. Two identical thin metal plates has charge q
1
and q
2
respectively such that q
1
> q
2
. The plates were
brought close to each other to form a parallel plate
capacitor of capacitance C. The potential
difference between them is :
(A)
? ?
12
qq
C
?
(B)
? ?
12
qq
C
?
(C)
? ?
12
qq
2C
?
(D)
? ?
12
2 q q
C
?
Official Ans. by NTA (C)
Sol. Electric field between plates
12
0
qq
E
2A
?
?
?
V = Ed =
12
0
qq
d
2A
?
?
V =
12
qq
2C
?
2
4. Given below are two statements: one is labelled as
Assertion A and the other is labelled as Reason R.
Assertion A: Alloys such as constantan and
manganin are used in making standard resistance
coils.
Reason R: Constantan and manganin have very
small value of temperature coefficient of
resistance.
In the light of the above statements, choose the
correct answer from the options given below.
(A) Both A and R are true and R is the correct
explanation of A.
(B) Both A and R are true but R is NOT the correct
explanation of A.
(C) A is true but R is false.
(D) A is false but R is true.
Official Ans. by NTA (A)
Sol. Theory based
5. A 1 m long wire is broken into two unequal parts
X and Y The X part of the wire is streched into
another wire W. Length of W is twice the length of
X and the resistance of W is twice that of Y. Find
the ratio of length of X and Y.
(A) 1 : 4 (B) 1 : 2
(C) 4 :1 (D) 2 : 1
Official Ans. by NTA (B)
Sol.
Y X
? 1– ?
W
2 ?
XX
YY
R
R
?
When wire is stretched to double of its length, then
resistance becomes 4 times
R
W
= 4R
X
= 2R
Y
X
Y
R 1
R2
?
X
y
1
So.
2
?
6. A wire X of length 50 cm carrying a current of 2 A
is placed parallel to a long wire Y of length 5 m.
The wire Y carries a current of 3 A. The distance
between two wires is 5 cm and currents flow in the
same direction. The force acting on the wire Y is :
X
2A 3A
5cm
Y
(A) 1.2 × 10
–5
N directed towards wire X.
(B) 1.2 × 10
–4
N directed away from wire X.
(C) 1.2 × 10
–4
N directed towards wire X.
(D) 2.4 × 10
–5
N directed towards wire X.
Official Ans. by NTA (A)
Sol. Force of interaction = I
1
?
1
B
12
0 1 2
1
II
2r
?
?
?
7
2
4 10 6 0.5
2 5 10
?
?
? ? ? ?
?
? ? ?
= 1.2 × 10
–5
towards X
7. A juggler throws balls vertically upwards with
same initial velocity in air. When the first ball
reaches its highest position, he throws the next
ball. Assuming the juggler throws n balls per
second, the maximum height the balls can reach is
(A) g/2n (B) g/n
(C) 2gn (D) g/2n
2
Official Ans. by NTA (D)
Sol. Time taken by ball to reach highest point =
u
g
Frequency of throw =
g
n
u
?
g
u
n
??
2
2
max
g
u n
H
2g 2g
??
??
??
??
2
g
2n
3
8. A circuit element X when connected to an a.c.
supply of peak voltage 100 V gives a peak current
of 5 A which is in phase with the voltage. A
second element Y when connected to the same a.c.
supply also gives the same value of peak current
which lags behind the voltage by
2
?
. If X and Y
are connected in series to the same supply, what
will be the rms value of the current in ampere ?
(A)
10
2
(B)
5
2
(C) 52 (D)
5
2
Official Ans. by NTA (D)
Sol. Element X should be resistive with R = 20 ?
Element Y should be inductive with X
L
= 20 ? ?
When X and Y are connector in series
22
L
Z X R 20 2 ? ? ?
0
0
E 100 5
IA
Z 20 2 2
? ? ?
0
rms
I 5
IA
2 2
??
9. An unpolarised light beam of intensity 2I
0
is
passed through a polaroid P and then through
another polaroid Q which is oriented in such a way
that its passing axis makes an angle of 30° relative
to that of P. The intensity of the emergent light is
(A)
0
I
4
(B)
0
I
2
(C)
0
3I
4
(D)
0
3I
2
Official Ans. by NTA (C)
Sol.
I
1
I
2
2I
0
? ?
1 0 0
1
I 2I I
2
??
I
2
= I
1
cos
2
30º
0
0
3I 3
I.
44
??
10. An ? particle and a proton are accelerated from
rest through the same potential difference. The
ratio of linear momenta acquired by above two
particals will be :
(A) 2 :1 (B) 2 2 :1
(C) 4 2 : 1 (D) 8 : 1
Official Ans. by NTA (B)
Sol. p 2mE 2mqV ??
p p p
p m q 42
p m q 1 1
? ? ?
? ? ?
22
1
?
11. Read the following statements:
(A) Volume of the nucleus is directly proportional
to the mass number.
(B) Volume of the nucleus is independent of mass
number.
(C) Density of the nucleus is directly proportional
to the mass number.
(D) Density of the nucleus is directly proportional
to the cube root of the mass number.
(E) Density of the nucleus is independent of the
mass number.
Choose the correct option from the following
options.
(A) (A) and (D) only. (B) (A) and (E) only.
(C) (B) and (E) only. (D) (A) and (C) only
Official Ans. by NTA (B)
Sol. R ? A
1/3
3
4
V R A
3
? ? ?
Mass ? A
So density is independent of A.
4
12. An object of mass 1 kg is taken to a height from
the surface of earth which is equal to three times
the radius of earth. The gain in potential energy of
the object will be
[If, g=10ms
–2
and radius of earth = 6400 km]
(A) 48 MJ (B) 24 MJ
(C) 36 MJ (D) 12 MJ
Official Ans. by NTA (A)
Sol.
i
GMm
U
R
?
?
f
GMm
U
4R
??
fi
3GMm
U U U
4R
? ? ? ?
3
mgR
4
?
5
3
1 10 64 10
4
? ? ? ? ?
= 48 MJ
13. A ball is released from a height h. If t
1
and t
2
be the
time required to complete first half and second half
of the distance respectively. Then, choose the
correct relation between t
1
and t
2
.
(A)
? ?
12
t 2 t ? (B)
? ?
12
t 2 1 t ??
(C)
? ?
21
t 2 1 t ?? (D)
? ?
21
t 2 1 t ??
Official Ans. by NTA (D)
Sol. For first
h
2
2
1
h1
gt
22
?
For total height h
? ?
2
12
1
h g t t
2
??
1
12
t 1
tt 2
?
?
2
1
t
12
t
??
1
2
t 1
t 21
?
?
? ? 21
t 2 1 t ??
14. Two bodies of masses m
1
= 5 kg and m
2
= 3 kg are
connected by a light string going over a smooth
light pulley on a smooth inclined plane as shown in
the figure. The system is at rest. The force exerted
by the inclined plane on the body of mass m
1
will
be :[Take g = 10 ms
–2
]
?
m
1
m
2
(A) 30 N (B) 40 N
(C) 50 N (D) 60 N
Official Ans. by NTA (B)
Sol. For equilibrium m
2
g = m
1
g sin ?
2
1
m 3
sin
m5
? ? ?
4
cos
5
??
Normal force on m
1
= 5g cos ?
4
5 10 40 N
5
? ? ? ?
15. If momentum of a body is increased by 20%, then
its kinetic energy increases by :
(A) 36% (B) 40%
(C) 44% (D) 48%
Official Ans. by NTA (C)
Sol.
20
P' P P 1.2 P
100
? ? ?
% change in KE =
K' K
100
K
?
?
22
2
P' P
2m 2m
100
P
2m
??
?
??
?? ??
??
??
??
= [(1.2)
2
– 1] × 100
= 44 %
Page 5
1
FINAL JEE –MAIN EXAMINATION – JULY, 2022
(Held On Friday 29
th
July, 2022) TIME : 3 : 00 PM to 06 : 00 PM
PHYSICS
TEST PAPER WITH SOLUTION
SECTION-A
1. Two identical metallic spheres A and B when
placed at certain distance in air repel each other
with a force of F. Another identical uncharged
sphere C is first placed in contact with A and then
in contact with B and finally placed at midpoint
between spheres A and B. The force experienced
by sphere C will be :
(A) 3F/2 (B) 3F/4
(C) F (D) 2F
Official Ans. by NTA (B)
Sol. Let q
A
= q
B
= q
A B
r
2
2
Kq
F
r
?
When C is placed in contact with A, charge on A
& C will be =
q
2
Now C is placed in contact with B, charge on B &
C will be =
q
q
3q
2
24
?
?
Now,
A B
F
1
C
F
2
r
2
r
2
3q
4
3q
4
q
2
21
2
3q q
KK
42
F' F F
r
4
??
?
??
??
? ? ? .
3q
4
2
2
3Kq 3F
4 4r
?? (B)
2. Match List I with List II.
List I List II
A. Torque I. Nms
–1
B. Stress II. J kg
–1
C.
Latent
Heat III. Nm
D. Power IV. Nm
–2
Choose the correct answer from the options given
below:
(A) A-III, B-II, C-I, D-IV
(B) A-III, B-IV, C-II, D-I
(C) A-IV, B-I, C-III, D-II
(D) A-II, B-III, C-I, D-IV
Official Ans. by NTA (B)
Sol. Torque = Fr
?
? Nm
Stress =
Force
Area
N/m
2
Latent heat =
Energy
Mass
J Kg
–1
Power =
Work
Time
N ms
–1
A-III, B-IV, C-II, D-I
3. Two identical thin metal plates has charge q
1
and q
2
respectively such that q
1
> q
2
. The plates were
brought close to each other to form a parallel plate
capacitor of capacitance C. The potential
difference between them is :
(A)
? ?
12
qq
C
?
(B)
? ?
12
qq
C
?
(C)
? ?
12
qq
2C
?
(D)
? ?
12
2 q q
C
?
Official Ans. by NTA (C)
Sol. Electric field between plates
12
0
qq
E
2A
?
?
?
V = Ed =
12
0
qq
d
2A
?
?
V =
12
qq
2C
?
2
4. Given below are two statements: one is labelled as
Assertion A and the other is labelled as Reason R.
Assertion A: Alloys such as constantan and
manganin are used in making standard resistance
coils.
Reason R: Constantan and manganin have very
small value of temperature coefficient of
resistance.
In the light of the above statements, choose the
correct answer from the options given below.
(A) Both A and R are true and R is the correct
explanation of A.
(B) Both A and R are true but R is NOT the correct
explanation of A.
(C) A is true but R is false.
(D) A is false but R is true.
Official Ans. by NTA (A)
Sol. Theory based
5. A 1 m long wire is broken into two unequal parts
X and Y The X part of the wire is streched into
another wire W. Length of W is twice the length of
X and the resistance of W is twice that of Y. Find
the ratio of length of X and Y.
(A) 1 : 4 (B) 1 : 2
(C) 4 :1 (D) 2 : 1
Official Ans. by NTA (B)
Sol.
Y X
? 1– ?
W
2 ?
XX
YY
R
R
?
When wire is stretched to double of its length, then
resistance becomes 4 times
R
W
= 4R
X
= 2R
Y
X
Y
R 1
R2
?
X
y
1
So.
2
?
6. A wire X of length 50 cm carrying a current of 2 A
is placed parallel to a long wire Y of length 5 m.
The wire Y carries a current of 3 A. The distance
between two wires is 5 cm and currents flow in the
same direction. The force acting on the wire Y is :
X
2A 3A
5cm
Y
(A) 1.2 × 10
–5
N directed towards wire X.
(B) 1.2 × 10
–4
N directed away from wire X.
(C) 1.2 × 10
–4
N directed towards wire X.
(D) 2.4 × 10
–5
N directed towards wire X.
Official Ans. by NTA (A)
Sol. Force of interaction = I
1
?
1
B
12
0 1 2
1
II
2r
?
?
?
7
2
4 10 6 0.5
2 5 10
?
?
? ? ? ?
?
? ? ?
= 1.2 × 10
–5
towards X
7. A juggler throws balls vertically upwards with
same initial velocity in air. When the first ball
reaches its highest position, he throws the next
ball. Assuming the juggler throws n balls per
second, the maximum height the balls can reach is
(A) g/2n (B) g/n
(C) 2gn (D) g/2n
2
Official Ans. by NTA (D)
Sol. Time taken by ball to reach highest point =
u
g
Frequency of throw =
g
n
u
?
g
u
n
??
2
2
max
g
u n
H
2g 2g
??
??
??
??
2
g
2n
3
8. A circuit element X when connected to an a.c.
supply of peak voltage 100 V gives a peak current
of 5 A which is in phase with the voltage. A
second element Y when connected to the same a.c.
supply also gives the same value of peak current
which lags behind the voltage by
2
?
. If X and Y
are connected in series to the same supply, what
will be the rms value of the current in ampere ?
(A)
10
2
(B)
5
2
(C) 52 (D)
5
2
Official Ans. by NTA (D)
Sol. Element X should be resistive with R = 20 ?
Element Y should be inductive with X
L
= 20 ? ?
When X and Y are connector in series
22
L
Z X R 20 2 ? ? ?
0
0
E 100 5
IA
Z 20 2 2
? ? ?
0
rms
I 5
IA
2 2
??
9. An unpolarised light beam of intensity 2I
0
is
passed through a polaroid P and then through
another polaroid Q which is oriented in such a way
that its passing axis makes an angle of 30° relative
to that of P. The intensity of the emergent light is
(A)
0
I
4
(B)
0
I
2
(C)
0
3I
4
(D)
0
3I
2
Official Ans. by NTA (C)
Sol.
I
1
I
2
2I
0
? ?
1 0 0
1
I 2I I
2
??
I
2
= I
1
cos
2
30º
0
0
3I 3
I.
44
??
10. An ? particle and a proton are accelerated from
rest through the same potential difference. The
ratio of linear momenta acquired by above two
particals will be :
(A) 2 :1 (B) 2 2 :1
(C) 4 2 : 1 (D) 8 : 1
Official Ans. by NTA (B)
Sol. p 2mE 2mqV ??
p p p
p m q 42
p m q 1 1
? ? ?
? ? ?
22
1
?
11. Read the following statements:
(A) Volume of the nucleus is directly proportional
to the mass number.
(B) Volume of the nucleus is independent of mass
number.
(C) Density of the nucleus is directly proportional
to the mass number.
(D) Density of the nucleus is directly proportional
to the cube root of the mass number.
(E) Density of the nucleus is independent of the
mass number.
Choose the correct option from the following
options.
(A) (A) and (D) only. (B) (A) and (E) only.
(C) (B) and (E) only. (D) (A) and (C) only
Official Ans. by NTA (B)
Sol. R ? A
1/3
3
4
V R A
3
? ? ?
Mass ? A
So density is independent of A.
4
12. An object of mass 1 kg is taken to a height from
the surface of earth which is equal to three times
the radius of earth. The gain in potential energy of
the object will be
[If, g=10ms
–2
and radius of earth = 6400 km]
(A) 48 MJ (B) 24 MJ
(C) 36 MJ (D) 12 MJ
Official Ans. by NTA (A)
Sol.
i
GMm
U
R
?
?
f
GMm
U
4R
??
fi
3GMm
U U U
4R
? ? ? ?
3
mgR
4
?
5
3
1 10 64 10
4
? ? ? ? ?
= 48 MJ
13. A ball is released from a height h. If t
1
and t
2
be the
time required to complete first half and second half
of the distance respectively. Then, choose the
correct relation between t
1
and t
2
.
(A)
? ?
12
t 2 t ? (B)
? ?
12
t 2 1 t ??
(C)
? ?
21
t 2 1 t ?? (D)
? ?
21
t 2 1 t ??
Official Ans. by NTA (D)
Sol. For first
h
2
2
1
h1
gt
22
?
For total height h
? ?
2
12
1
h g t t
2
??
1
12
t 1
tt 2
?
?
2
1
t
12
t
??
1
2
t 1
t 21
?
?
? ? 21
t 2 1 t ??
14. Two bodies of masses m
1
= 5 kg and m
2
= 3 kg are
connected by a light string going over a smooth
light pulley on a smooth inclined plane as shown in
the figure. The system is at rest. The force exerted
by the inclined plane on the body of mass m
1
will
be :[Take g = 10 ms
–2
]
?
m
1
m
2
(A) 30 N (B) 40 N
(C) 50 N (D) 60 N
Official Ans. by NTA (B)
Sol. For equilibrium m
2
g = m
1
g sin ?
2
1
m 3
sin
m5
? ? ?
4
cos
5
??
Normal force on m
1
= 5g cos ?
4
5 10 40 N
5
? ? ? ?
15. If momentum of a body is increased by 20%, then
its kinetic energy increases by :
(A) 36% (B) 40%
(C) 44% (D) 48%
Official Ans. by NTA (C)
Sol.
20
P' P P 1.2 P
100
? ? ?
% change in KE =
K' K
100
K
?
?
22
2
P' P
2m 2m
100
P
2m
??
?
??
?? ??
??
??
??
= [(1.2)
2
– 1] × 100
= 44 %
5
16. The torque of a force
ˆˆ ˆ
5i 3j 7k ?? about the origin
is ?. If the force acts on a particle whose position
vector is
ˆˆ ˆ
2i 2j k ?? , then the value of ? will be :
(A)
ˆˆ ˆ
11i 19j 4k ?? (B)
ˆˆ ˆ
11i 9j 16k ? ? ?
(C)
ˆˆ ˆ
17i 19j 4k ? ? ? (D)
ˆˆ ˆ
17i 9j 16k ??
Official Ans. by NTA (C)
Sol.
i j k
r F 2 2 1
5 3 7
? ? ? ?
?
? ? ? ? ? ?
ˆ
i 14 3 j 14 5 k 6 10 ? ? ? ? ? ? ? ?
ˆ ˆ ˆ
17i 19j 4k ? ? ? ?
17. A thermodynamic system is taken from an original
state D to an intermediate state E by the linear
process shown in the figure. Its volume is then
reduced to the original volume from E to F by an
isobaric process. The total work done by the gas
from D to E to F will be
E
F
300
0 2.0 5.0
D
600
Volume V,(m )
3
Pressure-P(N/m )
2
(A) –450 J (B) 450 J
(C) 900 J (D) 1350 J
Official Ans. by NTA (B)
Sol. ? ?
DE
1
W 600 300 3
2
?? J
= 1350 J
EF
W 3 0 0 3 – 9 0 0 J ? ? ? ?
DEF
W 450J ?
18. The vertical component of the earth's magnetic
field is 6 × 10
–5
T at any place where the angle of
dip is 37º. The earth's resultant magnetic field at
that place will be (Given tan 37º =
3
4
)
(A) 8 × 10
–5
T (B) 6 × 10
–5
T
(C) 5 × 10
–4
T (D) 1 × 10
–4
T
Official Ans. by NTA (D)
Sol.
B
?
( ? = 37°)
B
V
= B sin ?
6 × 10
–5
=
3
B
5
B = 10 × 10
–5
T
= 10
–4
T
19. The root mean square speed of smoke particles of
mass 5 × 10
–17
kg in their Brownian motion in air at
NTP is approximately. [Given k = 1.38 × 10
–23
JK
–1
]
(A) 60 mm s
–1
(B) 12 mm s
–1
(C) 15 mm s
–1
(D) 36 mm s
–1
Official Ans. by NTA (C)
Sol.
23
rms
17
3kT 3 1.38 10 293
V
m 5 10
?
?
? ? ?
??
?
15mm / s ?
20. Light enters from air into a given medium at an
angle of 45° with interface of the air-medium
surface. After refraction, the light ray is deviated
through an angle of 15° from its original direction.
The refractive index of the medium is :
(A) 1.732 (B) 1.333
(C) 1.414 (D) 2.732
Official Ans. by NTA (C)
Read More