Page 1
SECTION - A
1. A child stands on the edge of the cliff 10 m above the ground and throws a stone horizontally with an
initial speed of 5 ms
-1
. Neglecting the air resistance, the speed with which the stone hits the ground
will be __ ms
-1
(given, ?? = 10 ms
-2
).
(1) 15 (2) 20 (3) 30 (4) 25
Sol. (1)
Along vertical direction
sy = 10 m
= 15 m/s
2. Let ?? be the uniform surface charge density of two infinite thin plane sheets shown in figure. Then the
electric fields in three different region ?? ?? ,?? ????
and ?? ??????
are:
(1) ?? ?
?? =
2?? ?? 0
?? ˆ,?? ?
????
= 0,?? ?
??????
=
2?? ?? 0
?? ˆ (2) ?? ?
?? =
?? 2?? 0
?? ˆ,?? ?
????
= 0,?? ?
??????
=
?? 2?? 0
?? ˆ
(3) ?? ?
?? = -
?? ?? 0
?? ˆ,?? ?
????
= 0,?? ?
??????
=
?? ?? 0
?? ˆ (4) ?? ?
?? = 0,?? ?
????
=
?? ?? 0
?? ˆ,?? ??????
= 0
5m/s
v
g
10m
= 25 200 ? = 225
??
xy
v v v ?
22
y
v 200 ?
2
y
v 200 ?
y
v ? ?
2
?? =
2
(0) 2 10 10 ? ? ? ag
y
??
y y y y
v u 2a g u0 ?
22
y
JEE –MAIN EXAMINATION – JANUARY, 2023
(Held On Thursday 1st February, 2023) TIME : 9 : 00 AM to 12 : 00 NOON
Page 2
SECTION - A
1. A child stands on the edge of the cliff 10 m above the ground and throws a stone horizontally with an
initial speed of 5 ms
-1
. Neglecting the air resistance, the speed with which the stone hits the ground
will be __ ms
-1
(given, ?? = 10 ms
-2
).
(1) 15 (2) 20 (3) 30 (4) 25
Sol. (1)
Along vertical direction
sy = 10 m
= 15 m/s
2. Let ?? be the uniform surface charge density of two infinite thin plane sheets shown in figure. Then the
electric fields in three different region ?? ?? ,?? ????
and ?? ??????
are:
(1) ?? ?
?? =
2?? ?? 0
?? ˆ,?? ?
????
= 0,?? ?
??????
=
2?? ?? 0
?? ˆ (2) ?? ?
?? =
?? 2?? 0
?? ˆ,?? ?
????
= 0,?? ?
??????
=
?? 2?? 0
?? ˆ
(3) ?? ?
?? = -
?? ?? 0
?? ˆ,?? ?
????
= 0,?? ?
??????
=
?? ?? 0
?? ˆ (4) ?? ?
?? = 0,?? ?
????
=
?? ?? 0
?? ˆ,?? ??????
= 0
5m/s
v
g
10m
= 25 200 ? = 225
??
xy
v v v ?
22
y
v 200 ?
2
y
v 200 ?
y
v ? ?
2
?? =
2
(0) 2 10 10 ? ? ? ag
y
??
y y y y
v u 2a g u0 ?
22
y
JEE –MAIN EXAMINATION – JANUARY, 2023
(Held On Thursday 1st February, 2023) TIME : 9 : 00 AM to 12 : 00 NOON
Sol. (3)
I
0
ˆ En
E
?
? ? ?
II
E0 ??
III
0
ˆ En
E
?
? ? ?
3. A mercury drop of radius 10
-3
m is broken into 125 equal size droplets.
Surface tension of mercury is 0.45Nm
-1
. The gain in surface energy is:
(1) 28× 10
-5
J (2) 17.5 × 10
-5
J (3) 5 × 10
-5
J (4) 2.26× 10
-5
J
Sol. (4)
[Volume of bigger drop] = [volume of smaller drop] × 125
33
44
R 125 r
33
? ? ? ?
33
R 125r ?
R 5 r ? ? ?
? Gain in sinface energy = TdA
? ?
21
0.45 A A ? ? ?
22
0.45 125 4 r 4 R ?? ? ? ? ? ? ?
??
2
2
R
0.45 125 4 4 R
5
??
??
? ? ? ? ? ?
??
??
??
??
??
22
0.45 20 R 4 R ?? ? ? ? ? ?
??
2
0.45 16 R ? ? ?
? ?
2
3
0.45 16 3.14 10
?
? ? ? ?
5
2.26 10 J
?
??
4. If earth has a mass nine times and radius twice to that of a planet P. Then
?? ?? 3
v?? ms
-1
will be the
minimum velocity required by a rocket to pull out of gravitational force of P, where ?? ?? is escape
velocity on earth. The value of ?? is
(1) 1 (2) 3 (3) 18 (4) 2
E 1
(I)
(II)
(III)
E 1
E 2
E 2
E 1
E 2
E 1
d
+ ?
+ ?
Page 3
SECTION - A
1. A child stands on the edge of the cliff 10 m above the ground and throws a stone horizontally with an
initial speed of 5 ms
-1
. Neglecting the air resistance, the speed with which the stone hits the ground
will be __ ms
-1
(given, ?? = 10 ms
-2
).
(1) 15 (2) 20 (3) 30 (4) 25
Sol. (1)
Along vertical direction
sy = 10 m
= 15 m/s
2. Let ?? be the uniform surface charge density of two infinite thin plane sheets shown in figure. Then the
electric fields in three different region ?? ?? ,?? ????
and ?? ??????
are:
(1) ?? ?
?? =
2?? ?? 0
?? ˆ,?? ?
????
= 0,?? ?
??????
=
2?? ?? 0
?? ˆ (2) ?? ?
?? =
?? 2?? 0
?? ˆ,?? ?
????
= 0,?? ?
??????
=
?? 2?? 0
?? ˆ
(3) ?? ?
?? = -
?? ?? 0
?? ˆ,?? ?
????
= 0,?? ?
??????
=
?? ?? 0
?? ˆ (4) ?? ?
?? = 0,?? ?
????
=
?? ?? 0
?? ˆ,?? ??????
= 0
5m/s
v
g
10m
= 25 200 ? = 225
??
xy
v v v ?
22
y
v 200 ?
2
y
v 200 ?
y
v ? ?
2
?? =
2
(0) 2 10 10 ? ? ? ag
y
??
y y y y
v u 2a g u0 ?
22
y
JEE –MAIN EXAMINATION – JANUARY, 2023
(Held On Thursday 1st February, 2023) TIME : 9 : 00 AM to 12 : 00 NOON
Sol. (3)
I
0
ˆ En
E
?
? ? ?
II
E0 ??
III
0
ˆ En
E
?
? ? ?
3. A mercury drop of radius 10
-3
m is broken into 125 equal size droplets.
Surface tension of mercury is 0.45Nm
-1
. The gain in surface energy is:
(1) 28× 10
-5
J (2) 17.5 × 10
-5
J (3) 5 × 10
-5
J (4) 2.26× 10
-5
J
Sol. (4)
[Volume of bigger drop] = [volume of smaller drop] × 125
33
44
R 125 r
33
? ? ? ?
33
R 125r ?
R 5 r ? ? ?
? Gain in sinface energy = TdA
? ?
21
0.45 A A ? ? ?
22
0.45 125 4 r 4 R ?? ? ? ? ? ? ?
??
2
2
R
0.45 125 4 4 R
5
??
??
? ? ? ? ? ?
??
??
??
??
??
22
0.45 20 R 4 R ?? ? ? ? ? ?
??
2
0.45 16 R ? ? ?
? ?
2
3
0.45 16 3.14 10
?
? ? ? ?
5
2.26 10 J
?
??
4. If earth has a mass nine times and radius twice to that of a planet P. Then
?? ?? 3
v?? ms
-1
will be the
minimum velocity required by a rocket to pull out of gravitational force of P, where ?? ?? is escape
velocity on earth. The value of ?? is
(1) 1 (2) 3 (3) 18 (4) 2
E 1
(I)
(II)
(III)
E 1
E 2
E 2
E 1
E 2
E 1
d
+ ?
+ ?
Sol. (4)
EP
M 9M ?
EP
R 2R ?
E
1 P
c
E
P
M
2G
2GM
9
V
R
R
2
??
E
E
2GM 2
R9
??
1 e
c
V
V2
3
?
5. A sample of gas at temperature ?? is adiabatically expanded to double its volume. The work done by
the gas in the process is
3
given, ?
2
:
(1) ?? =
?? ?? [v2- 2] (2) ?? = ???? [2- v2] (3) ?? = ???? [v2- 2] (4) ?? =
?? ?? [2- v2]
Sol. (2)
Work done in the process is given by
12
R
W (T T )
1
??
??
For adiabatic process:
11
1 1 2 2
T V T V
? ? ? ?
?
33
11
22
2
TV T (2V)
??
?
11
22
2
TV T (2V) ?
22
2
T V T 2V ??
2
T
T
2
??
RT
WT
1 2
??
? ? ? ?
??
??
??
=
1
2RT 1
2
??
?
??
??
=
2
RT 2
2
??
?
??
??
= RT[2 2] ?
W RT 2 2
??
??
??
Page 4
SECTION - A
1. A child stands on the edge of the cliff 10 m above the ground and throws a stone horizontally with an
initial speed of 5 ms
-1
. Neglecting the air resistance, the speed with which the stone hits the ground
will be __ ms
-1
(given, ?? = 10 ms
-2
).
(1) 15 (2) 20 (3) 30 (4) 25
Sol. (1)
Along vertical direction
sy = 10 m
= 15 m/s
2. Let ?? be the uniform surface charge density of two infinite thin plane sheets shown in figure. Then the
electric fields in three different region ?? ?? ,?? ????
and ?? ??????
are:
(1) ?? ?
?? =
2?? ?? 0
?? ˆ,?? ?
????
= 0,?? ?
??????
=
2?? ?? 0
?? ˆ (2) ?? ?
?? =
?? 2?? 0
?? ˆ,?? ?
????
= 0,?? ?
??????
=
?? 2?? 0
?? ˆ
(3) ?? ?
?? = -
?? ?? 0
?? ˆ,?? ?
????
= 0,?? ?
??????
=
?? ?? 0
?? ˆ (4) ?? ?
?? = 0,?? ?
????
=
?? ?? 0
?? ˆ,?? ??????
= 0
5m/s
v
g
10m
= 25 200 ? = 225
??
xy
v v v ?
22
y
v 200 ?
2
y
v 200 ?
y
v ? ?
2
?? =
2
(0) 2 10 10 ? ? ? ag
y
??
y y y y
v u 2a g u0 ?
22
y
JEE –MAIN EXAMINATION – JANUARY, 2023
(Held On Thursday 1st February, 2023) TIME : 9 : 00 AM to 12 : 00 NOON
Sol. (3)
I
0
ˆ En
E
?
? ? ?
II
E0 ??
III
0
ˆ En
E
?
? ? ?
3. A mercury drop of radius 10
-3
m is broken into 125 equal size droplets.
Surface tension of mercury is 0.45Nm
-1
. The gain in surface energy is:
(1) 28× 10
-5
J (2) 17.5 × 10
-5
J (3) 5 × 10
-5
J (4) 2.26× 10
-5
J
Sol. (4)
[Volume of bigger drop] = [volume of smaller drop] × 125
33
44
R 125 r
33
? ? ? ?
33
R 125r ?
R 5 r ? ? ?
? Gain in sinface energy = TdA
? ?
21
0.45 A A ? ? ?
22
0.45 125 4 r 4 R ?? ? ? ? ? ? ?
??
2
2
R
0.45 125 4 4 R
5
??
??
? ? ? ? ? ?
??
??
??
??
??
22
0.45 20 R 4 R ?? ? ? ? ? ?
??
2
0.45 16 R ? ? ?
? ?
2
3
0.45 16 3.14 10
?
? ? ? ?
5
2.26 10 J
?
??
4. If earth has a mass nine times and radius twice to that of a planet P. Then
?? ?? 3
v?? ms
-1
will be the
minimum velocity required by a rocket to pull out of gravitational force of P, where ?? ?? is escape
velocity on earth. The value of ?? is
(1) 1 (2) 3 (3) 18 (4) 2
E 1
(I)
(II)
(III)
E 1
E 2
E 2
E 1
E 2
E 1
d
+ ?
+ ?
Sol. (4)
EP
M 9M ?
EP
R 2R ?
E
1 P
c
E
P
M
2G
2GM
9
V
R
R
2
??
E
E
2GM 2
R9
??
1 e
c
V
V2
3
?
5. A sample of gas at temperature ?? is adiabatically expanded to double its volume. The work done by
the gas in the process is
3
given, ?
2
:
(1) ?? =
?? ?? [v2- 2] (2) ?? = ???? [2- v2] (3) ?? = ???? [v2- 2] (4) ?? =
?? ?? [2- v2]
Sol. (2)
Work done in the process is given by
12
R
W (T T )
1
??
??
For adiabatic process:
11
1 1 2 2
T V T V
? ? ? ?
?
33
11
22
2
TV T (2V)
??
?
11
22
2
TV T (2V) ?
22
2
T V T 2V ??
2
T
T
2
??
RT
WT
1 2
??
? ? ? ?
??
??
??
=
1
2RT 1
2
??
?
??
??
=
2
RT 2
2
??
?
??
??
= RT[2 2] ?
W RT 2 2
??
??
??
6.
2
a
P (V– b) RT
V
represents the equation of state of some gases. Where P is the pressure, ?? is the
volume, ?? is the temperature and ?? ,?? ,?? are the constants. The physical quantity, which has
dimensional formula as that of
?? 2
?? , will be:
(1) Compressibility (2) Energy density
(3) Modulus of rigidity (4) Bulk modulus
Sol. (1)
? ?
3
bL ?? ?
??
? ?
2
a PV ?? ?
??
=
1 2 6
ML T L
??
? ? ? ?
? ? ? ?
=
52
ML T
?
??
??
? ?
26
1 1 2
52
bL
M L T
a ML T
?
?
? ? ? ?
? ? ? ?
?? ??
??
??
??
7. The equivalent resistance between ?? and ?? of the network shown in figure:
(1)
8
3
R (2) 21R (3) 14R (4) 11
2
3
R
Sol. (1)
The given network is wheat-stone network
?
eq
4R 8R
R
4R 8R
?
?
?
4R 8R
12R
?
?
eq
8
RR
3
?
R
2R
6R
3R
Page 5
SECTION - A
1. A child stands on the edge of the cliff 10 m above the ground and throws a stone horizontally with an
initial speed of 5 ms
-1
. Neglecting the air resistance, the speed with which the stone hits the ground
will be __ ms
-1
(given, ?? = 10 ms
-2
).
(1) 15 (2) 20 (3) 30 (4) 25
Sol. (1)
Along vertical direction
sy = 10 m
= 15 m/s
2. Let ?? be the uniform surface charge density of two infinite thin plane sheets shown in figure. Then the
electric fields in three different region ?? ?? ,?? ????
and ?? ??????
are:
(1) ?? ?
?? =
2?? ?? 0
?? ˆ,?? ?
????
= 0,?? ?
??????
=
2?? ?? 0
?? ˆ (2) ?? ?
?? =
?? 2?? 0
?? ˆ,?? ?
????
= 0,?? ?
??????
=
?? 2?? 0
?? ˆ
(3) ?? ?
?? = -
?? ?? 0
?? ˆ,?? ?
????
= 0,?? ?
??????
=
?? ?? 0
?? ˆ (4) ?? ?
?? = 0,?? ?
????
=
?? ?? 0
?? ˆ,?? ??????
= 0
5m/s
v
g
10m
= 25 200 ? = 225
??
xy
v v v ?
22
y
v 200 ?
2
y
v 200 ?
y
v ? ?
2
?? =
2
(0) 2 10 10 ? ? ? ag
y
??
y y y y
v u 2a g u0 ?
22
y
JEE –MAIN EXAMINATION – JANUARY, 2023
(Held On Thursday 1st February, 2023) TIME : 9 : 00 AM to 12 : 00 NOON
Sol. (3)
I
0
ˆ En
E
?
? ? ?
II
E0 ??
III
0
ˆ En
E
?
? ? ?
3. A mercury drop of radius 10
-3
m is broken into 125 equal size droplets.
Surface tension of mercury is 0.45Nm
-1
. The gain in surface energy is:
(1) 28× 10
-5
J (2) 17.5 × 10
-5
J (3) 5 × 10
-5
J (4) 2.26× 10
-5
J
Sol. (4)
[Volume of bigger drop] = [volume of smaller drop] × 125
33
44
R 125 r
33
? ? ? ?
33
R 125r ?
R 5 r ? ? ?
? Gain in sinface energy = TdA
? ?
21
0.45 A A ? ? ?
22
0.45 125 4 r 4 R ?? ? ? ? ? ? ?
??
2
2
R
0.45 125 4 4 R
5
??
??
? ? ? ? ? ?
??
??
??
??
??
22
0.45 20 R 4 R ?? ? ? ? ? ?
??
2
0.45 16 R ? ? ?
? ?
2
3
0.45 16 3.14 10
?
? ? ? ?
5
2.26 10 J
?
??
4. If earth has a mass nine times and radius twice to that of a planet P. Then
?? ?? 3
v?? ms
-1
will be the
minimum velocity required by a rocket to pull out of gravitational force of P, where ?? ?? is escape
velocity on earth. The value of ?? is
(1) 1 (2) 3 (3) 18 (4) 2
E 1
(I)
(II)
(III)
E 1
E 2
E 2
E 1
E 2
E 1
d
+ ?
+ ?
Sol. (4)
EP
M 9M ?
EP
R 2R ?
E
1 P
c
E
P
M
2G
2GM
9
V
R
R
2
??
E
E
2GM 2
R9
??
1 e
c
V
V2
3
?
5. A sample of gas at temperature ?? is adiabatically expanded to double its volume. The work done by
the gas in the process is
3
given, ?
2
:
(1) ?? =
?? ?? [v2- 2] (2) ?? = ???? [2- v2] (3) ?? = ???? [v2- 2] (4) ?? =
?? ?? [2- v2]
Sol. (2)
Work done in the process is given by
12
R
W (T T )
1
??
??
For adiabatic process:
11
1 1 2 2
T V T V
? ? ? ?
?
33
11
22
2
TV T (2V)
??
?
11
22
2
TV T (2V) ?
22
2
T V T 2V ??
2
T
T
2
??
RT
WT
1 2
??
? ? ? ?
??
??
??
=
1
2RT 1
2
??
?
??
??
=
2
RT 2
2
??
?
??
??
= RT[2 2] ?
W RT 2 2
??
??
??
6.
2
a
P (V– b) RT
V
represents the equation of state of some gases. Where P is the pressure, ?? is the
volume, ?? is the temperature and ?? ,?? ,?? are the constants. The physical quantity, which has
dimensional formula as that of
?? 2
?? , will be:
(1) Compressibility (2) Energy density
(3) Modulus of rigidity (4) Bulk modulus
Sol. (1)
? ?
3
bL ?? ?
??
? ?
2
a PV ?? ?
??
=
1 2 6
ML T L
??
? ? ? ?
? ? ? ?
=
52
ML T
?
??
??
? ?
26
1 1 2
52
bL
M L T
a ML T
?
?
? ? ? ?
? ? ? ?
?? ??
??
??
??
7. The equivalent resistance between ?? and ?? of the network shown in figure:
(1)
8
3
R (2) 21R (3) 14R (4) 11
2
3
R
Sol. (1)
The given network is wheat-stone network
?
eq
4R 8R
R
4R 8R
?
?
?
4R 8R
12R
?
?
eq
8
RR
3
?
R
2R
6R
3R
8. Match List I with List II:
List I List II
A. AC generator I. Presence of both L and C
B. Transformer II. Electromagnetic Induction
C. Resonance phenomenon to occur III. Quality factor
D. Sharpness of resonance IV. Mutual Induction
Choose the correct answer from the options given below:
(1) A-IV, B-III, C-I, D-II (2) A-IV, B-II, C-I, D-III
(3) A-II, B-IV, C-I, D-III (4) A-II, B-I, C-III, D-IV
Sol. (3)
(A) A.C. generator ? II. Electro-magnetic induction
(B) transformer ? IV Mutual induction
(C) Resonance phenomenon to occur ? (I) presence of both L and C
(D) Sharpness of resonance ? (III) Quality factor
9. An object moves with speed ?? 1
,?? 2
and ?? 3
along a line segment AB,BC and CD respectively as shown
in figure. Where AB = BC and AD = 3AB, then average speed of the object will be:
(1)
(?? 1
+?? 2
+?? 3
)
3?? 1
?? 2
?? 3
(2)
(?? 1
+?? 2
+?? 3
)
3
(3)
3?? 1
?? 2
?? 3
(?? 1
?? 2
+?? 2
?? 3
+?? 3
?? 1
)
(4)
?? 1
?? 2
?? 3
3(?? 1
?? 2
+?? 2
?? 3
+?? 3
?? 1
)
Sol. (3)
<v> =
Total distance
Total time
1 2 3
3x
x x x
v v v
?
??
2 3 1 3 1 2
1 2 3 1 2 3
33
v v v v v v 1 1 1
v v v v v v
??
? ? ? ? ??
??
? ? ? ?
? ? ? ?
<v> =
? ?
1 2 3
3 2 1 2 1 2
3v v v
v v v v v v ??
x
A
v 1 v 2
v 3 B C D
x x
Read More