Page 1
JEE Main Previous Year Questions
(2025): Simple Harmonic motion
(SHM) and Oscillations
Q1: Given below are two statements. One is labelled as Assertion (A) and the other is
labelled as Reason (R).
Assertion (A) : A simple pendulum is taken to a planet of mass and radius, 4 times and
2 times, respectively, than the Earth. The time period of the pendulum remains same
on earth and the planet.
Reason ( ?? ) : The mass of the pendulum remains unchanged at Earth and the other
planet.
In the light of the above statements, choose the correct answer from the options
given below :
JEE Main 2025 (Online) 22nd January Evening Shift
Options:
A. Both (A) and (R) are true and (R) is the correct explanation of (A)
B. (A) is false but (R) is true
C. (A) is true but (R) is false
D. Both (A) and (R) are true but (R) is NOT the correct explanation of (A)
Ans: D
Solution:
Assertion (A): A simple pendulum transported to a planet where the mass and radius are 4 times
and 2 times that of the Earth, respectively, has the same time period as it does on Earth.
Reason (R): The mass of the pendulum remains unchanged whether on Earth or the other
planet.
Explanation:
The acceleration due to gravity ?? on a planet is given by the formula:
?? =
????
?? 2
where ?? is the gravitational constant, ?? is the mass of the planet, and ?? is the radius of the
planet.
For the new planet, the gravitational acceleration ?? '
is:
?? '
=
?? ( 4 ?? )
( 2 ?? )
2
=
4 ????
4 ?? 2
=
????
?? 2
= ??
Thus, the gravitational acceleration on this new planet is the same as on Earth, ?? .
The time period ?? of a simple pendulum is determined by:
Page 2
JEE Main Previous Year Questions
(2025): Simple Harmonic motion
(SHM) and Oscillations
Q1: Given below are two statements. One is labelled as Assertion (A) and the other is
labelled as Reason (R).
Assertion (A) : A simple pendulum is taken to a planet of mass and radius, 4 times and
2 times, respectively, than the Earth. The time period of the pendulum remains same
on earth and the planet.
Reason ( ?? ) : The mass of the pendulum remains unchanged at Earth and the other
planet.
In the light of the above statements, choose the correct answer from the options
given below :
JEE Main 2025 (Online) 22nd January Evening Shift
Options:
A. Both (A) and (R) are true and (R) is the correct explanation of (A)
B. (A) is false but (R) is true
C. (A) is true but (R) is false
D. Both (A) and (R) are true but (R) is NOT the correct explanation of (A)
Ans: D
Solution:
Assertion (A): A simple pendulum transported to a planet where the mass and radius are 4 times
and 2 times that of the Earth, respectively, has the same time period as it does on Earth.
Reason (R): The mass of the pendulum remains unchanged whether on Earth or the other
planet.
Explanation:
The acceleration due to gravity ?? on a planet is given by the formula:
?? =
????
?? 2
where ?? is the gravitational constant, ?? is the mass of the planet, and ?? is the radius of the
planet.
For the new planet, the gravitational acceleration ?? '
is:
?? '
=
?? ( 4 ?? )
( 2 ?? )
2
=
4 ????
4 ?? 2
=
????
?? 2
= ??
Thus, the gravitational acceleration on this new planet is the same as on Earth, ?? .
The time period ?? of a simple pendulum is determined by:
?? = 2 ?? v
l
??
where l is the length of the pendulum, which indicates that the time period ?? is independent of
the mass of the pendulum.
Therefore, while Assertion (A) is true and Reason (R) is true, Reason (R) does not correctly
explain Assertion (A) because the time period of the pendulum is also independent of the
pendulum's mass, and the key factor is the unchanged gravitational acceleration.
Q2: A light hollow cube of side length 10 cm and mass 10 g , is floating in water. It is
pushed down and released to execute simple harmonic oscillations. The time period of
oscillations is ???? × ????
- ?? ?? , where the value of ?? is(Acceleration due to gravity, ?? =
???? ?? /?? ?? , density of water = ????
?? ???? /?? ?? )
JEE Main 2025 (Online) 23rd January Morning Shift
Options:
A. 2
B. 4
C. 1
D. 6
Ans: A
Solution:
We can determine the time period of the oscillations by considering that when the cube is
depressed by a small displacement, the additional buoyant force provided by the displaced
water acts as a restoring force. Here's a step-by-step explanation:
Define the given values:
Side length of the cube, ?? = 10 cm = 0 . 1 m.
Mass of the cube, ?? = 10 g = 0 . 01 kg.
Density of water, ?? = 10
3
kg / m
3
.
Acceleration due to gravity, ?? = 10 m / s
2
.
Cross-sectional area of the cube (face area),
?? = ?? 2
= ( 0 . 1 )
2
= 0 . 01 m
2
.
When the cube is depressed by a small distance ?? , the additional volume of water displaced is
? ?? = ???? .
Thus, the additional buoyant force is:
?? ?? = ???? ? ?? = ?????? ?? .
This force acts in the upward (restoring) direction. Notice that the force is proportional to the
displacement ?? , which is the hallmark of simple harmonic motion (SHM).
The effective spring constant, ?? , associated with this SHM is:
Page 3
JEE Main Previous Year Questions
(2025): Simple Harmonic motion
(SHM) and Oscillations
Q1: Given below are two statements. One is labelled as Assertion (A) and the other is
labelled as Reason (R).
Assertion (A) : A simple pendulum is taken to a planet of mass and radius, 4 times and
2 times, respectively, than the Earth. The time period of the pendulum remains same
on earth and the planet.
Reason ( ?? ) : The mass of the pendulum remains unchanged at Earth and the other
planet.
In the light of the above statements, choose the correct answer from the options
given below :
JEE Main 2025 (Online) 22nd January Evening Shift
Options:
A. Both (A) and (R) are true and (R) is the correct explanation of (A)
B. (A) is false but (R) is true
C. (A) is true but (R) is false
D. Both (A) and (R) are true but (R) is NOT the correct explanation of (A)
Ans: D
Solution:
Assertion (A): A simple pendulum transported to a planet where the mass and radius are 4 times
and 2 times that of the Earth, respectively, has the same time period as it does on Earth.
Reason (R): The mass of the pendulum remains unchanged whether on Earth or the other
planet.
Explanation:
The acceleration due to gravity ?? on a planet is given by the formula:
?? =
????
?? 2
where ?? is the gravitational constant, ?? is the mass of the planet, and ?? is the radius of the
planet.
For the new planet, the gravitational acceleration ?? '
is:
?? '
=
?? ( 4 ?? )
( 2 ?? )
2
=
4 ????
4 ?? 2
=
????
?? 2
= ??
Thus, the gravitational acceleration on this new planet is the same as on Earth, ?? .
The time period ?? of a simple pendulum is determined by:
?? = 2 ?? v
l
??
where l is the length of the pendulum, which indicates that the time period ?? is independent of
the mass of the pendulum.
Therefore, while Assertion (A) is true and Reason (R) is true, Reason (R) does not correctly
explain Assertion (A) because the time period of the pendulum is also independent of the
pendulum's mass, and the key factor is the unchanged gravitational acceleration.
Q2: A light hollow cube of side length 10 cm and mass 10 g , is floating in water. It is
pushed down and released to execute simple harmonic oscillations. The time period of
oscillations is ???? × ????
- ?? ?? , where the value of ?? is(Acceleration due to gravity, ?? =
???? ?? /?? ?? , density of water = ????
?? ???? /?? ?? )
JEE Main 2025 (Online) 23rd January Morning Shift
Options:
A. 2
B. 4
C. 1
D. 6
Ans: A
Solution:
We can determine the time period of the oscillations by considering that when the cube is
depressed by a small displacement, the additional buoyant force provided by the displaced
water acts as a restoring force. Here's a step-by-step explanation:
Define the given values:
Side length of the cube, ?? = 10 cm = 0 . 1 m.
Mass of the cube, ?? = 10 g = 0 . 01 kg.
Density of water, ?? = 10
3
kg / m
3
.
Acceleration due to gravity, ?? = 10 m / s
2
.
Cross-sectional area of the cube (face area),
?? = ?? 2
= ( 0 . 1 )
2
= 0 . 01 m
2
.
When the cube is depressed by a small distance ?? , the additional volume of water displaced is
? ?? = ???? .
Thus, the additional buoyant force is:
?? ?? = ???? ? ?? = ?????? ?? .
This force acts in the upward (restoring) direction. Notice that the force is proportional to the
displacement ?? , which is the hallmark of simple harmonic motion (SHM).
The effective spring constant, ?? , associated with this SHM is:
?? = ?????? .
The period of oscillation for SHM is given by:
?? = 2 ?? v
?? ?? ,
which, upon substituting for ?? , becomes:
?? = 2 ?? v
?? ?????? .
Substitute the given values into the expression:
?? = 2 ?? v
0 . 01
1000 × 10 × 0 . 01
.
Calculate the denominator:
1000 × 10 × 0 . 01 = 100 ,
so,
?? = 2 ?? v
0 . 01
100
= 2 ?? v 0 . 0001 .
Since,
v 0 . 0001 = 0 . 01,
we have:
?? = 2 ?? × 0 . 01 = 0 . 02 ?? s.
The problem states that the time period is given by:
???? × 10
- 2
s.
Writing our result in the same form:
0 . 02 ?? s = 2 ?? × 10
- 2
s.
We see that ?? = 2.
Therefore, the correct answer is:
Option A: 2.
Q3: A particle is executing simple harmonic motion with time period 2 s and amplitude
1 cm . If D and d are the total distance and displacement covered by the particle in
12.5 s , then
?? ?? is
JEE Main 2025 (Online) 24th January Morning Shift
Options:
A. 10
B.
16
5
Page 4
JEE Main Previous Year Questions
(2025): Simple Harmonic motion
(SHM) and Oscillations
Q1: Given below are two statements. One is labelled as Assertion (A) and the other is
labelled as Reason (R).
Assertion (A) : A simple pendulum is taken to a planet of mass and radius, 4 times and
2 times, respectively, than the Earth. The time period of the pendulum remains same
on earth and the planet.
Reason ( ?? ) : The mass of the pendulum remains unchanged at Earth and the other
planet.
In the light of the above statements, choose the correct answer from the options
given below :
JEE Main 2025 (Online) 22nd January Evening Shift
Options:
A. Both (A) and (R) are true and (R) is the correct explanation of (A)
B. (A) is false but (R) is true
C. (A) is true but (R) is false
D. Both (A) and (R) are true but (R) is NOT the correct explanation of (A)
Ans: D
Solution:
Assertion (A): A simple pendulum transported to a planet where the mass and radius are 4 times
and 2 times that of the Earth, respectively, has the same time period as it does on Earth.
Reason (R): The mass of the pendulum remains unchanged whether on Earth or the other
planet.
Explanation:
The acceleration due to gravity ?? on a planet is given by the formula:
?? =
????
?? 2
where ?? is the gravitational constant, ?? is the mass of the planet, and ?? is the radius of the
planet.
For the new planet, the gravitational acceleration ?? '
is:
?? '
=
?? ( 4 ?? )
( 2 ?? )
2
=
4 ????
4 ?? 2
=
????
?? 2
= ??
Thus, the gravitational acceleration on this new planet is the same as on Earth, ?? .
The time period ?? of a simple pendulum is determined by:
?? = 2 ?? v
l
??
where l is the length of the pendulum, which indicates that the time period ?? is independent of
the mass of the pendulum.
Therefore, while Assertion (A) is true and Reason (R) is true, Reason (R) does not correctly
explain Assertion (A) because the time period of the pendulum is also independent of the
pendulum's mass, and the key factor is the unchanged gravitational acceleration.
Q2: A light hollow cube of side length 10 cm and mass 10 g , is floating in water. It is
pushed down and released to execute simple harmonic oscillations. The time period of
oscillations is ???? × ????
- ?? ?? , where the value of ?? is(Acceleration due to gravity, ?? =
???? ?? /?? ?? , density of water = ????
?? ???? /?? ?? )
JEE Main 2025 (Online) 23rd January Morning Shift
Options:
A. 2
B. 4
C. 1
D. 6
Ans: A
Solution:
We can determine the time period of the oscillations by considering that when the cube is
depressed by a small displacement, the additional buoyant force provided by the displaced
water acts as a restoring force. Here's a step-by-step explanation:
Define the given values:
Side length of the cube, ?? = 10 cm = 0 . 1 m.
Mass of the cube, ?? = 10 g = 0 . 01 kg.
Density of water, ?? = 10
3
kg / m
3
.
Acceleration due to gravity, ?? = 10 m / s
2
.
Cross-sectional area of the cube (face area),
?? = ?? 2
= ( 0 . 1 )
2
= 0 . 01 m
2
.
When the cube is depressed by a small distance ?? , the additional volume of water displaced is
? ?? = ???? .
Thus, the additional buoyant force is:
?? ?? = ???? ? ?? = ?????? ?? .
This force acts in the upward (restoring) direction. Notice that the force is proportional to the
displacement ?? , which is the hallmark of simple harmonic motion (SHM).
The effective spring constant, ?? , associated with this SHM is:
?? = ?????? .
The period of oscillation for SHM is given by:
?? = 2 ?? v
?? ?? ,
which, upon substituting for ?? , becomes:
?? = 2 ?? v
?? ?????? .
Substitute the given values into the expression:
?? = 2 ?? v
0 . 01
1000 × 10 × 0 . 01
.
Calculate the denominator:
1000 × 10 × 0 . 01 = 100 ,
so,
?? = 2 ?? v
0 . 01
100
= 2 ?? v 0 . 0001 .
Since,
v 0 . 0001 = 0 . 01,
we have:
?? = 2 ?? × 0 . 01 = 0 . 02 ?? s.
The problem states that the time period is given by:
???? × 10
- 2
s.
Writing our result in the same form:
0 . 02 ?? s = 2 ?? × 10
- 2
s.
We see that ?? = 2.
Therefore, the correct answer is:
Option A: 2.
Q3: A particle is executing simple harmonic motion with time period 2 s and amplitude
1 cm . If D and d are the total distance and displacement covered by the particle in
12.5 s , then
?? ?? is
JEE Main 2025 (Online) 24th January Morning Shift
Options:
A. 10
B.
16
5
C. 25
D.
15
4
Ans: C
Solution:
?? ( ?? ) = c os ? ( ???? )
The particle executes simple harmonic motion (SHM) with amplitude ?? = 1 cm and period ?? =
2 s. In one complete cycle ( 2 s ), the motion is as follows:
It starts at ?? = 1 cm.
It moves to ?? = - 1 cm (covering a distance of 2 cm ).
It returns to ?? = 1 cm (covering another 2 cm ).
Thus, the total distance traveled in one complete cycle is:
?? cycle
= 2 + 2 = 4 cm.
In 12.5 s , the number of cycles is:
12 . 5
2
= 6 . 25 cycles.
For the 6 complete cycles ( 12 s ), the distance traveled is:
?? complete
= 6 × 4 = 24 cm.
For the remaining 0.5 s , determine the displacement. At ?? = 12 s, the particle is at:
?? ( 12 ) = c os ? ( 12 ?? ) = 1 cm.
After an extra 0.5 s (i.e., at ?? = 12 . 5 s ), the position becomes:
?? ( 12 . 5 ) = c os ? ( 12 . 5 ?? ) = c os ? ( 12 ?? +
?? 2
) = c os ?
?? 2
= 0 cm.
The distance covered in this interval is:
?? extra
= | 1 - 0 | = 1 cm.
So, the total distance traveled is:
?? = ?? complete
? + ?? extra
= 24 + 1 = 25 cm.
The net displacement, which is the difference between the final and initial positions, is
calculated as follows:
Initial position at ?? = 0 :
?? ( 0 ) = c os ? 0 = 1 cm,
Final position at ?? = 12 . 5 s :
?? ( 12 . 5 ) = 0 cm.
Thus, the displacement is:
?? = | 0 - 1 | = 1 cm.
The ratio of the total distance traveled to the displacement is:
?? ?? =
25
1
= 25.
Therefore, the correct answer is 25 .
Q4: A particle oscillates along the ?? -axis according to the law, ?? ( ?? ) = ?? ?? ?? ???? ?? ? (
?? ?? )
where ?? ?? = ?? ?? . The kinetic energy ( K ) of the particle as a function of ?? is correctly
represented by the graph
JEE Main 2025 (Online) 24th January Evening Shift
Options:
Page 5
JEE Main Previous Year Questions
(2025): Simple Harmonic motion
(SHM) and Oscillations
Q1: Given below are two statements. One is labelled as Assertion (A) and the other is
labelled as Reason (R).
Assertion (A) : A simple pendulum is taken to a planet of mass and radius, 4 times and
2 times, respectively, than the Earth. The time period of the pendulum remains same
on earth and the planet.
Reason ( ?? ) : The mass of the pendulum remains unchanged at Earth and the other
planet.
In the light of the above statements, choose the correct answer from the options
given below :
JEE Main 2025 (Online) 22nd January Evening Shift
Options:
A. Both (A) and (R) are true and (R) is the correct explanation of (A)
B. (A) is false but (R) is true
C. (A) is true but (R) is false
D. Both (A) and (R) are true but (R) is NOT the correct explanation of (A)
Ans: D
Solution:
Assertion (A): A simple pendulum transported to a planet where the mass and radius are 4 times
and 2 times that of the Earth, respectively, has the same time period as it does on Earth.
Reason (R): The mass of the pendulum remains unchanged whether on Earth or the other
planet.
Explanation:
The acceleration due to gravity ?? on a planet is given by the formula:
?? =
????
?? 2
where ?? is the gravitational constant, ?? is the mass of the planet, and ?? is the radius of the
planet.
For the new planet, the gravitational acceleration ?? '
is:
?? '
=
?? ( 4 ?? )
( 2 ?? )
2
=
4 ????
4 ?? 2
=
????
?? 2
= ??
Thus, the gravitational acceleration on this new planet is the same as on Earth, ?? .
The time period ?? of a simple pendulum is determined by:
?? = 2 ?? v
l
??
where l is the length of the pendulum, which indicates that the time period ?? is independent of
the mass of the pendulum.
Therefore, while Assertion (A) is true and Reason (R) is true, Reason (R) does not correctly
explain Assertion (A) because the time period of the pendulum is also independent of the
pendulum's mass, and the key factor is the unchanged gravitational acceleration.
Q2: A light hollow cube of side length 10 cm and mass 10 g , is floating in water. It is
pushed down and released to execute simple harmonic oscillations. The time period of
oscillations is ???? × ????
- ?? ?? , where the value of ?? is(Acceleration due to gravity, ?? =
???? ?? /?? ?? , density of water = ????
?? ???? /?? ?? )
JEE Main 2025 (Online) 23rd January Morning Shift
Options:
A. 2
B. 4
C. 1
D. 6
Ans: A
Solution:
We can determine the time period of the oscillations by considering that when the cube is
depressed by a small displacement, the additional buoyant force provided by the displaced
water acts as a restoring force. Here's a step-by-step explanation:
Define the given values:
Side length of the cube, ?? = 10 cm = 0 . 1 m.
Mass of the cube, ?? = 10 g = 0 . 01 kg.
Density of water, ?? = 10
3
kg / m
3
.
Acceleration due to gravity, ?? = 10 m / s
2
.
Cross-sectional area of the cube (face area),
?? = ?? 2
= ( 0 . 1 )
2
= 0 . 01 m
2
.
When the cube is depressed by a small distance ?? , the additional volume of water displaced is
? ?? = ???? .
Thus, the additional buoyant force is:
?? ?? = ???? ? ?? = ?????? ?? .
This force acts in the upward (restoring) direction. Notice that the force is proportional to the
displacement ?? , which is the hallmark of simple harmonic motion (SHM).
The effective spring constant, ?? , associated with this SHM is:
?? = ?????? .
The period of oscillation for SHM is given by:
?? = 2 ?? v
?? ?? ,
which, upon substituting for ?? , becomes:
?? = 2 ?? v
?? ?????? .
Substitute the given values into the expression:
?? = 2 ?? v
0 . 01
1000 × 10 × 0 . 01
.
Calculate the denominator:
1000 × 10 × 0 . 01 = 100 ,
so,
?? = 2 ?? v
0 . 01
100
= 2 ?? v 0 . 0001 .
Since,
v 0 . 0001 = 0 . 01,
we have:
?? = 2 ?? × 0 . 01 = 0 . 02 ?? s.
The problem states that the time period is given by:
???? × 10
- 2
s.
Writing our result in the same form:
0 . 02 ?? s = 2 ?? × 10
- 2
s.
We see that ?? = 2.
Therefore, the correct answer is:
Option A: 2.
Q3: A particle is executing simple harmonic motion with time period 2 s and amplitude
1 cm . If D and d are the total distance and displacement covered by the particle in
12.5 s , then
?? ?? is
JEE Main 2025 (Online) 24th January Morning Shift
Options:
A. 10
B.
16
5
C. 25
D.
15
4
Ans: C
Solution:
?? ( ?? ) = c os ? ( ???? )
The particle executes simple harmonic motion (SHM) with amplitude ?? = 1 cm and period ?? =
2 s. In one complete cycle ( 2 s ), the motion is as follows:
It starts at ?? = 1 cm.
It moves to ?? = - 1 cm (covering a distance of 2 cm ).
It returns to ?? = 1 cm (covering another 2 cm ).
Thus, the total distance traveled in one complete cycle is:
?? cycle
= 2 + 2 = 4 cm.
In 12.5 s , the number of cycles is:
12 . 5
2
= 6 . 25 cycles.
For the 6 complete cycles ( 12 s ), the distance traveled is:
?? complete
= 6 × 4 = 24 cm.
For the remaining 0.5 s , determine the displacement. At ?? = 12 s, the particle is at:
?? ( 12 ) = c os ? ( 12 ?? ) = 1 cm.
After an extra 0.5 s (i.e., at ?? = 12 . 5 s ), the position becomes:
?? ( 12 . 5 ) = c os ? ( 12 . 5 ?? ) = c os ? ( 12 ?? +
?? 2
) = c os ?
?? 2
= 0 cm.
The distance covered in this interval is:
?? extra
= | 1 - 0 | = 1 cm.
So, the total distance traveled is:
?? = ?? complete
? + ?? extra
= 24 + 1 = 25 cm.
The net displacement, which is the difference between the final and initial positions, is
calculated as follows:
Initial position at ?? = 0 :
?? ( 0 ) = c os ? 0 = 1 cm,
Final position at ?? = 12 . 5 s :
?? ( 12 . 5 ) = 0 cm.
Thus, the displacement is:
?? = | 0 - 1 | = 1 cm.
The ratio of the total distance traveled to the displacement is:
?? ?? =
25
1
= 25.
Therefore, the correct answer is 25 .
Q4: A particle oscillates along the ?? -axis according to the law, ?? ( ?? ) = ?? ?? ?? ???? ?? ? (
?? ?? )
where ?? ?? = ?? ?? . The kinetic energy ( K ) of the particle as a function of ?? is correctly
represented by the graph
JEE Main 2025 (Online) 24th January Evening Shift
Options:
A.
B.
C.
D.
Ans: D
Solution:
?? = ?? 0
s i n
2
?
?? 2
= ?? 0
(
1 - c os ? ?? 2
)
?? -
?? 0
2
=
- c o s ? ?? 2
where ?? 0
= 1
?? -
1
2
=
- c os ? ?? 2
Particle is oscillating between x = 0 to x = 1
Q5: Given below are two statements. One is labelled as Assertion (A) and the other is
labelled as Reason (R).
Assertion (A) : Knowing initial position ?? ?? and initial momentum ?? ?? is enough to
determine the position and momentum at any time ?? for a simple harmonic motion
with a given angular frequency ?? .
Reason ( ?? ) : The amplitude and phase can be expressed in terms of ?? ?? an ?? ?? .
In the light of the above statements, choose the correct answer from the options
given below :
JEE Main 2025 (Online) 28th January Evening Shift
Options:
A. (A) is true but (R) is false
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