Physics
Grade-9
Easy
Question
Force acting in simple harmonic motion is always:
- Directly proportional to the square of the displacement
- Inversely proportional to the displacement
- Inversely proportional to the square of the displacement
- Directly proportional to the displacement
Hint:
, F = −kx,
The correct answer is: Directly proportional to the displacement
- The force responsible for the motion is always directed toward the equilibrium position and is directly proportional to the distance from it. That is, F = −kx, where F is the force, x is the displacement, and k is a constant. This relation is called Hooke's law.
- So Directly proportional to the displacement
Related Questions to study
Physics
Choose the correct statement from the following:
Assertion: In oscillatory motion, displacement of a body from equilibrium can be represented by sine or cosine function.
Reason: The body oscillates to and from about its mean position.
- Assertion is correct, the reason is correct; the reason is not a correct explanation for assertion
- Assertion is incorrect, the reason is correct
- Assertion is correct, the reason is correct; the reason is a correct explanation for assertion
- Assertion is correct, reason is incorrect
Choose the correct statement from the following:
Assertion: In oscillatory motion, displacement of a body from equilibrium can be represented by sine or cosine function.
Reason: The body oscillates to and from about its mean position.
PhysicsGrade-9
- Assertion is correct, the reason is correct; the reason is not a correct explanation for assertion
- Assertion is incorrect, the reason is correct
- Assertion is correct, the reason is correct; the reason is a correct explanation for assertion
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Physics
The displacement time graph of a particle executing S.H.M. is as shown in the figure:

The corresponding force-time graph will be:
The displacement time graph of a particle executing S.H.M. is as shown in the figure:

The corresponding force-time graph will be:
PhysicsGrade-9
Physics
Assertion: All small oscillations are simple harmonic.
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Assertion: All small oscillations are simple harmonic.
Reason: Oscillations of a simple pendulum system are always simple harmonic whether the amplitude is small or large.
PhysicsGrade-9
- If both the assertion and reason are true but the reason is not the correct explanation of assertion.
- If the assertion is false but the reason is true.
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Physics
Two simple pendulums of length 1 m and 16 m respectively are given small displacements at the same time in the same direction. The number of oscillations ‘N’ of the smaller pendulum for them to be in phase again is:
- 4 / 3
- 3 / 4
- 4
- 1 / 16
Two simple pendulums of length 1 m and 16 m respectively are given small displacements at the same time in the same direction. The number of oscillations ‘N’ of the smaller pendulum for them to be in phase again is:
PhysicsGrade-9
- 4 / 3
- 3 / 4
- 4
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Physics
Select the true statement(s) about SHM.
I. Acceleration display style alpha displacement is a sufficient condition for SHM.
II. Restoring force display style alpha displacement is a sufficient condition for SHM.
- Both I and II are wrong
- II only
- I only
- I and II
Select the true statement(s) about SHM.
I. Acceleration display style alpha displacement is a sufficient condition for SHM.
II. Restoring force display style alpha displacement is a sufficient condition for SHM.
PhysicsGrade-9
- Both I and II are wrong
- II only
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What is constant in S.H.M.?
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What is constant in S.H.M.?
PhysicsGrade-9
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In a simple pendulum, the period of oscillation T is related to the length of the pendulum l as:
In a simple pendulum, the period of oscillation T is related to the length of the pendulum l as:
PhysicsGrade-9
Physics
Assertion: The amplitude of an oscillating pendulum decreases gradually with time
Reason: The frequency of the pendulum decreases with time.
- Assertion is correct, the reason is incorrect
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- Assertion is correct, the reason is correct; the reason is a correct explanation for assertion
Assertion: The amplitude of an oscillating pendulum decreases gradually with time
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- Assertion is correct, the reason is incorrect
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Vibrations, whose amplitudes of oscillations decrease with time are called:
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Vibrations, whose amplitudes of oscillations decrease with time are called:
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If the metal bob of a simple pendulum is replaced by a wooden bob, then its time period will:
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- Increase
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If the metal bob of a simple pendulum is replaced by a wooden bob, then its time period will:
PhysicsGrade-9
- Decrease
- Increase
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The time period of a simple pendulum is 2 sec. If its length is increased 4 times, then its period becomes:
- 8 sec
- 12 sec
- 16 sec
- 4 sec
The time period of a simple pendulum is 2 sec. If its length is increased 4 times, then its period becomes:
PhysicsGrade-9
- 8 sec
- 12 sec
- 16 sec
- 4 sec
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The total displacement of a particle in simple harmonic motion in one time period is:
- 4 A
- 2 A
- Zero
- A
The total displacement of a particle in simple harmonic motion in one time period is:
PhysicsGrade-9
- 4 A
- 2 A
- Zero
- A
Physics
For a body executing simple harmonic motion, which parameter comes out to be non-periodic?
- Displacement
- Acceleration
- Velocity
- None of these
For a body executing simple harmonic motion, which parameter comes out to be non-periodic?
PhysicsGrade-9
- Displacement
- Acceleration
- Velocity
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Select the incorrect statement(s) from the following.
I. A simple harmonic motion is necessarily periodic.
II. A simple harmonic motion may be oscillatory
III. An oscillatory motion is necessarily periodic
- I only
- I and II
- II and III
- I and III
Select the incorrect statement(s) from the following.
I. A simple harmonic motion is necessarily periodic.
II. A simple harmonic motion may be oscillatory
III. An oscillatory motion is necessarily periodic
PhysicsGrade-9
- I only
- I and II
- II and III
- I and III
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The time period of oscillations doesn’t depend upon:
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- Mass of the bob
- Gravitational acceleration
- Air resistance
The time period of oscillations doesn’t depend upon:
PhysicsGrade-9
- Length of the pendulum
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- Gravitational acceleration
- Air resistance