Work, Energy and Power: JEE Mains Previous Year Questions (2021-2024) | Physics for JEE Main & Advanced PDF Download

 Page 1


JEE Mains Previous Year Questions 
(2021-2024): Work, Energy & Power 
2024 
Q1: A body of mass ?? ???? begins to move under the action of a time dependent force given by 
?? ? ? 
= (?? ?? ??ˆ + ?? ?? ?? ??ˆ)?? . The power developed by the force at the time ?? is given by: 
A. (?? ?? ?? + ?? ?? ?? )?? 
B. (?? ?? ?? + ?? ?? ?? )?? 
C. (?? ?? ?? + ?? ?? ?? )?? 
D. (?? ?? ?? + ?? ?? ?? )??       [JEE Main 2024 (Online) 31st January Evening Shift] 
Ans: (d) 
?? 
= (6?? ??ˆ + 6?? 2
??ˆ)?? ?? 
= ?? ?? = (6?? ??ˆ + 6?? 2
??ˆ)
?? =
?? 
?? = (3?? ??ˆ + 3?? 2
??ˆ)
?? = ?
0
?? ??? ???? =
3?? 2
2
??ˆ + ?? 3
??ˆ
?? = ?? 
· ?? = (9?? 3
+ 6?? 5
)?? 
Q2: A block of mass ?? ???? is pushed up a surface inclined to horizontal at an angle of ????
°
 by a force of 
???? ?? parallel to the inclined surface as shown in figure. When the block is pushed up by ???? ?? along 
inclined surface, the work done against frictional force is : 
[?? = ???? ?? /?? ?? ] 
 
A. ?? v?? ?? 
B. ?? ?? 
C. ?? × ????
?? ?? 
Page 2


JEE Mains Previous Year Questions 
(2021-2024): Work, Energy & Power 
2024 
Q1: A body of mass ?? ???? begins to move under the action of a time dependent force given by 
?? ? ? 
= (?? ?? ??ˆ + ?? ?? ?? ??ˆ)?? . The power developed by the force at the time ?? is given by: 
A. (?? ?? ?? + ?? ?? ?? )?? 
B. (?? ?? ?? + ?? ?? ?? )?? 
C. (?? ?? ?? + ?? ?? ?? )?? 
D. (?? ?? ?? + ?? ?? ?? )??       [JEE Main 2024 (Online) 31st January Evening Shift] 
Ans: (d) 
?? 
= (6?? ??ˆ + 6?? 2
??ˆ)?? ?? 
= ?? ?? = (6?? ??ˆ + 6?? 2
??ˆ)
?? =
?? 
?? = (3?? ??ˆ + 3?? 2
??ˆ)
?? = ?
0
?? ??? ???? =
3?? 2
2
??ˆ + ?? 3
??ˆ
?? = ?? 
· ?? = (9?? 3
+ 6?? 5
)?? 
Q2: A block of mass ?? ???? is pushed up a surface inclined to horizontal at an angle of ????
°
 by a force of 
???? ?? parallel to the inclined surface as shown in figure. When the block is pushed up by ???? ?? along 
inclined surface, the work done against frictional force is : 
[?? = ???? ?? /?? ?? ] 
 
A. ?? v?? ?? 
B. ?? ?? 
C. ?? × ????
?? ?? 
D. ???? ??      [JEE Main 2024 (Online) 30th January Evening Shift] 
Ans: (b) 
Work done again frictional force 
 = ?? N × 10
 = 0.1 × 5 × 10 = 5 J
 
Q3: A particle is placed at the point ?? of a frictionless track ?????? as shown in figure. It is gently pushed 
towards right. The speed of the particle when it reaches the point ?? is: 
(Take ?? = ???? ?? /?? ?? ). 
 
A. ?? v???? ?? /?? 
B. ???? ?? /?? 
C. v???? ?? /?? 
D. ???? ?? /??     [JEE Main 2024 (Online) 30th January Morning Shift] 
Ans: (c) 
By COME 
KE
A
+ U
A
= KE
B
+ U
B
0 + mg(1) =
1
2
mv
2
+ mg × 0.5
?? = v?? = v10 m/s
 
 
Q4: A bob of mass ' ?? ' is suspended by a light string of length ' ?? '. It is imparted a minimum 
horizontal velocity at the lowest point ?? such that it just completes half circle reaching the top most 
position ?? . The ratio of kinetic energies 
(?? .?? )
?? (?? .?? )
?? is : 
 
 
Page 3


JEE Mains Previous Year Questions 
(2021-2024): Work, Energy & Power 
2024 
Q1: A body of mass ?? ???? begins to move under the action of a time dependent force given by 
?? ? ? 
= (?? ?? ??ˆ + ?? ?? ?? ??ˆ)?? . The power developed by the force at the time ?? is given by: 
A. (?? ?? ?? + ?? ?? ?? )?? 
B. (?? ?? ?? + ?? ?? ?? )?? 
C. (?? ?? ?? + ?? ?? ?? )?? 
D. (?? ?? ?? + ?? ?? ?? )??       [JEE Main 2024 (Online) 31st January Evening Shift] 
Ans: (d) 
?? 
= (6?? ??ˆ + 6?? 2
??ˆ)?? ?? 
= ?? ?? = (6?? ??ˆ + 6?? 2
??ˆ)
?? =
?? 
?? = (3?? ??ˆ + 3?? 2
??ˆ)
?? = ?
0
?? ??? ???? =
3?? 2
2
??ˆ + ?? 3
??ˆ
?? = ?? 
· ?? = (9?? 3
+ 6?? 5
)?? 
Q2: A block of mass ?? ???? is pushed up a surface inclined to horizontal at an angle of ????
°
 by a force of 
???? ?? parallel to the inclined surface as shown in figure. When the block is pushed up by ???? ?? along 
inclined surface, the work done against frictional force is : 
[?? = ???? ?? /?? ?? ] 
 
A. ?? v?? ?? 
B. ?? ?? 
C. ?? × ????
?? ?? 
D. ???? ??      [JEE Main 2024 (Online) 30th January Evening Shift] 
Ans: (b) 
Work done again frictional force 
 = ?? N × 10
 = 0.1 × 5 × 10 = 5 J
 
Q3: A particle is placed at the point ?? of a frictionless track ?????? as shown in figure. It is gently pushed 
towards right. The speed of the particle when it reaches the point ?? is: 
(Take ?? = ???? ?? /?? ?? ). 
 
A. ?? v???? ?? /?? 
B. ???? ?? /?? 
C. v???? ?? /?? 
D. ???? ?? /??     [JEE Main 2024 (Online) 30th January Morning Shift] 
Ans: (c) 
By COME 
KE
A
+ U
A
= KE
B
+ U
B
0 + mg(1) =
1
2
mv
2
+ mg × 0.5
?? = v?? = v10 m/s
 
 
Q4: A bob of mass ' ?? ' is suspended by a light string of length ' ?? '. It is imparted a minimum 
horizontal velocity at the lowest point ?? such that it just completes half circle reaching the top most 
position ?? . The ratio of kinetic energies 
(?? .?? )
?? (?? .?? )
?? is : 
 
 
 
 
 
 
A. ?? :?? 
B. ?? :?? 
C. ?? :?? 
D. ?? :??     [JEE Main 2024 (Online) 29th January Evening Shift] 
Ans: (a) 
Apply energy conservation between A & B 
1
2
mV
L
2
=
1
2
mV
H
2
+ mg(2 L)
 ? V
L
= v5gL
 
So, ?? ?? = v???? 
(K.E)
A
(K.E)
B
=
1
2
 m(vsgL)
2
1
2
 m(vgL)
2
=
5
1
 
Q5: A block of mass ?????? ???? slides over a distance of ???? ?? on a horizontal surface. If the co-efficient 
of friction between the surfaces is 0.4 , then the work done against friction (in ?? ) is : 
A. 3900 
B. 4500 
C. 4200 
D. 4000     [JEE Main 2024 (Online) 29th January Morning Shift] 
Ans: (d) 
 
Q6: The potential energy function (in ?? ) of a particle in a region of space is given as ?? = (?? ?? ?? +
?? ?? ?? + ?? ?? ). Here ?? ,?? and ?? are in meter. The magnitude of ?? component of force (in ?? ) acting on the 
particle at point ?? (?? ,?? ,?? )?? is : 
A. 4 
B. 2 
C. 8 
Page 4


JEE Mains Previous Year Questions 
(2021-2024): Work, Energy & Power 
2024 
Q1: A body of mass ?? ???? begins to move under the action of a time dependent force given by 
?? ? ? 
= (?? ?? ??ˆ + ?? ?? ?? ??ˆ)?? . The power developed by the force at the time ?? is given by: 
A. (?? ?? ?? + ?? ?? ?? )?? 
B. (?? ?? ?? + ?? ?? ?? )?? 
C. (?? ?? ?? + ?? ?? ?? )?? 
D. (?? ?? ?? + ?? ?? ?? )??       [JEE Main 2024 (Online) 31st January Evening Shift] 
Ans: (d) 
?? 
= (6?? ??ˆ + 6?? 2
??ˆ)?? ?? 
= ?? ?? = (6?? ??ˆ + 6?? 2
??ˆ)
?? =
?? 
?? = (3?? ??ˆ + 3?? 2
??ˆ)
?? = ?
0
?? ??? ???? =
3?? 2
2
??ˆ + ?? 3
??ˆ
?? = ?? 
· ?? = (9?? 3
+ 6?? 5
)?? 
Q2: A block of mass ?? ???? is pushed up a surface inclined to horizontal at an angle of ????
°
 by a force of 
???? ?? parallel to the inclined surface as shown in figure. When the block is pushed up by ???? ?? along 
inclined surface, the work done against frictional force is : 
[?? = ???? ?? /?? ?? ] 
 
A. ?? v?? ?? 
B. ?? ?? 
C. ?? × ????
?? ?? 
D. ???? ??      [JEE Main 2024 (Online) 30th January Evening Shift] 
Ans: (b) 
Work done again frictional force 
 = ?? N × 10
 = 0.1 × 5 × 10 = 5 J
 
Q3: A particle is placed at the point ?? of a frictionless track ?????? as shown in figure. It is gently pushed 
towards right. The speed of the particle when it reaches the point ?? is: 
(Take ?? = ???? ?? /?? ?? ). 
 
A. ?? v???? ?? /?? 
B. ???? ?? /?? 
C. v???? ?? /?? 
D. ???? ?? /??     [JEE Main 2024 (Online) 30th January Morning Shift] 
Ans: (c) 
By COME 
KE
A
+ U
A
= KE
B
+ U
B
0 + mg(1) =
1
2
mv
2
+ mg × 0.5
?? = v?? = v10 m/s
 
 
Q4: A bob of mass ' ?? ' is suspended by a light string of length ' ?? '. It is imparted a minimum 
horizontal velocity at the lowest point ?? such that it just completes half circle reaching the top most 
position ?? . The ratio of kinetic energies 
(?? .?? )
?? (?? .?? )
?? is : 
 
 
 
 
 
 
A. ?? :?? 
B. ?? :?? 
C. ?? :?? 
D. ?? :??     [JEE Main 2024 (Online) 29th January Evening Shift] 
Ans: (a) 
Apply energy conservation between A & B 
1
2
mV
L
2
=
1
2
mV
H
2
+ mg(2 L)
 ? V
L
= v5gL
 
So, ?? ?? = v???? 
(K.E)
A
(K.E)
B
=
1
2
 m(vsgL)
2
1
2
 m(vgL)
2
=
5
1
 
Q5: A block of mass ?????? ???? slides over a distance of ???? ?? on a horizontal surface. If the co-efficient 
of friction between the surfaces is 0.4 , then the work done against friction (in ?? ) is : 
A. 3900 
B. 4500 
C. 4200 
D. 4000     [JEE Main 2024 (Online) 29th January Morning Shift] 
Ans: (d) 
 
Q6: The potential energy function (in ?? ) of a particle in a region of space is given as ?? = (?? ?? ?? +
?? ?? ?? + ?? ?? ). Here ?? ,?? and ?? are in meter. The magnitude of ?? component of force (in ?? ) acting on the 
particle at point ?? (?? ,?? ,?? )?? is : 
A. 4 
B. 2 
C. 8 
D. 6      [JEE Main 2024 (Online) 29th January Morning Shift] 
Ans: (a) 
Q7: A bullet is fired into a fixed target looses one third of its velocity after travelling ?? ???? . It 
penetrates further ?? × ????
-?? ?? before coming to rest. The value of ?? is : 
A. 23 
B. 32 
C. 42 
D. 52     [JEE Main 2024 (Online) 27th January Evening Shift] 
Ans: (b) 
 
 
 
Page 5


JEE Mains Previous Year Questions 
(2021-2024): Work, Energy & Power 
2024 
Q1: A body of mass ?? ???? begins to move under the action of a time dependent force given by 
?? ? ? 
= (?? ?? ??ˆ + ?? ?? ?? ??ˆ)?? . The power developed by the force at the time ?? is given by: 
A. (?? ?? ?? + ?? ?? ?? )?? 
B. (?? ?? ?? + ?? ?? ?? )?? 
C. (?? ?? ?? + ?? ?? ?? )?? 
D. (?? ?? ?? + ?? ?? ?? )??       [JEE Main 2024 (Online) 31st January Evening Shift] 
Ans: (d) 
?? 
= (6?? ??ˆ + 6?? 2
??ˆ)?? ?? 
= ?? ?? = (6?? ??ˆ + 6?? 2
??ˆ)
?? =
?? 
?? = (3?? ??ˆ + 3?? 2
??ˆ)
?? = ?
0
?? ??? ???? =
3?? 2
2
??ˆ + ?? 3
??ˆ
?? = ?? 
· ?? = (9?? 3
+ 6?? 5
)?? 
Q2: A block of mass ?? ???? is pushed up a surface inclined to horizontal at an angle of ????
°
 by a force of 
???? ?? parallel to the inclined surface as shown in figure. When the block is pushed up by ???? ?? along 
inclined surface, the work done against frictional force is : 
[?? = ???? ?? /?? ?? ] 
 
A. ?? v?? ?? 
B. ?? ?? 
C. ?? × ????
?? ?? 
D. ???? ??      [JEE Main 2024 (Online) 30th January Evening Shift] 
Ans: (b) 
Work done again frictional force 
 = ?? N × 10
 = 0.1 × 5 × 10 = 5 J
 
Q3: A particle is placed at the point ?? of a frictionless track ?????? as shown in figure. It is gently pushed 
towards right. The speed of the particle when it reaches the point ?? is: 
(Take ?? = ???? ?? /?? ?? ). 
 
A. ?? v???? ?? /?? 
B. ???? ?? /?? 
C. v???? ?? /?? 
D. ???? ?? /??     [JEE Main 2024 (Online) 30th January Morning Shift] 
Ans: (c) 
By COME 
KE
A
+ U
A
= KE
B
+ U
B
0 + mg(1) =
1
2
mv
2
+ mg × 0.5
?? = v?? = v10 m/s
 
 
Q4: A bob of mass ' ?? ' is suspended by a light string of length ' ?? '. It is imparted a minimum 
horizontal velocity at the lowest point ?? such that it just completes half circle reaching the top most 
position ?? . The ratio of kinetic energies 
(?? .?? )
?? (?? .?? )
?? is : 
 
 
 
 
 
 
A. ?? :?? 
B. ?? :?? 
C. ?? :?? 
D. ?? :??     [JEE Main 2024 (Online) 29th January Evening Shift] 
Ans: (a) 
Apply energy conservation between A & B 
1
2
mV
L
2
=
1
2
mV
H
2
+ mg(2 L)
 ? V
L
= v5gL
 
So, ?? ?? = v???? 
(K.E)
A
(K.E)
B
=
1
2
 m(vsgL)
2
1
2
 m(vgL)
2
=
5
1
 
Q5: A block of mass ?????? ???? slides over a distance of ???? ?? on a horizontal surface. If the co-efficient 
of friction between the surfaces is 0.4 , then the work done against friction (in ?? ) is : 
A. 3900 
B. 4500 
C. 4200 
D. 4000     [JEE Main 2024 (Online) 29th January Morning Shift] 
Ans: (d) 
 
Q6: The potential energy function (in ?? ) of a particle in a region of space is given as ?? = (?? ?? ?? +
?? ?? ?? + ?? ?? ). Here ?? ,?? and ?? are in meter. The magnitude of ?? component of force (in ?? ) acting on the 
particle at point ?? (?? ,?? ,?? )?? is : 
A. 4 
B. 2 
C. 8 
D. 6      [JEE Main 2024 (Online) 29th January Morning Shift] 
Ans: (a) 
Q7: A bullet is fired into a fixed target looses one third of its velocity after travelling ?? ???? . It 
penetrates further ?? × ????
-?? ?? before coming to rest. The value of ?? is : 
A. 23 
B. 32 
C. 42 
D. 52     [JEE Main 2024 (Online) 27th January Evening Shift] 
Ans: (b) 
 
 
 
Numerical 
 
Q.1. A block of mass 10 kg is moving along x-axis under the 
action of force F=5x N. The work done by the force in moving the 
block from x=2m to 4m will be __________ J. 
JEE Main 2023 (Online) 15th April Morning Shift 
Q.2. A car accelerates from rest to  u m/s. The energy spent in 
this process is E J. The energy required to accelerate the car 
from  u m/s to 2um/s is  nE J. The value of n is ____________. 
JEE Main 2023 (Online) 13th April Evening Shift 
Q.3. To maintain a speed of 80 km/h by a bus of mass 500 kg on 
a plane rough road for 4 km distance, the work done by the 
engine of the bus will be ____________ KJ. [The coeffi cient of 
friction between tyre of bus and road is 0.04.] 
JEE Main 2023 (Online) 12th April Morning Shift 
Q.4. A block of mass  5 kg starting from rest pulled up on a 
smooth incline plane making an angle of 30 ° with horizontal with 
an affective acceleration of  1 ms-2. The power delivered by the 
pulling force at  t=10 s from the start is ___________ W. 
[use  g=10 ms-2 ] 
(calculate the nearest integer value) 
 
JEE Main 2023 (Online) 11th April Evening Shift