Physics

Oscillations and Periodic Motion

162 Questions

Oscillations and periodic motion describe the movement of objects repeating their paths in regular intervals. Key concepts include simple pendulums, kinetic energy variations, and mechanical resonance. This physics topic is vital for various competitive exams.

Simple pendulumTime period calculationsKinetic energy in SHMMechanical resonanceDamped oscillations

Oscillations and Periodic Motion Questions

Multiple choice

At what point the kinetic energy of the ball of simple pendulum has zero potential energy and maximum kinetic energy?

  1. At the mean position

  2. At the extreme ends

  3. When it is in motion, between left/ right ends and mean position.

  4. It is not possible that P.E=0 and K.E = max.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

It is correct as when the pendulum reaches the very bottom of the swing, it is at its lowest point and greatest speed. This means that the pendulum has zero potential energy and maximum kinetic energy.

Multiple choice

The time period of a pendulum on moon

  1. Decreases

  2. Increases

  3. Remains the same

  4. Is zero
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The time period of a simple pendulum is T = 2π√(L/g), where g is acceleration due to gravity. Since g on the moon (1.62 m/s²) is about 1/6th of g on Earth (9.81 m/s²), the time period increases by a factor of √6 ≈ 2.45. Lower gravity means slower oscillation, hence longer period.

Multiple choice

Why does a pendulum clock lose time during summers?

  1. The length of the pendulum decreases.

  2. The length of the pendulum increases.

  3. The mass of the bob increases.

  4. The acceleration due to gravity increases during summers.

  5. Amplitude of the pendulum clock increases.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The length of the pendulum increases during summers due to which the time period increases. So, the pendulum takes a longer time to complete one oscillation. Therefore, a pendulum clock loses time during summers.

Multiple choice

The time period of a simple pendulum oscillating in a laboratory at the north pole is 4s . Accounting for earth' s rotation only, what will be the time period of this pendulum oscillating in a laboratory ?

  1. less than 4s

  2. more than 4s

  3. equal to 4s

  4. infinity
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The time period of a simple pendulum is T = 2*pi*sqrt(L/g). At the North Pole, the effective gravity (g) is higher due to the Earth's rotation and shape. If the pendulum is moved to a location where g is lower (like the equator or mid-latitudes), the time period will increase.

Multiple choice

The time period of a pendulum on moon

  1. becomes zero

  2. increases

  3. remains the same

  4. decreases
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The time period of a pendulum is T = 2 * pi * sqrt(L/g). Since gravity on the moon is much lower than on Earth, the value of g decreases, which causes the time period T to increase.

Multiple choice

Match the following

 
Column I
Column II
A. Frequency

B. Amplitude
C. Pendulum
D. Periodic table | 1. Oscillation in unit time 2. A device consisting of a weight swinging on the end of a string 3. Chemical elements in order of their atomic numbers. 4. Maximum departure from an equilibrium value |

  1. A - 2, B - 1, C - 3, D - 4

  2. A - 1, B - 2, C - 4, D - 3

  3. A - 1, B - 4, C - 2, D - 3

  4. A - 4, B - 3, C - 1, D - 2
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Frequency is oscillations per unit time (A-1). Amplitude is maximum departure from equilibrium (B-4). A pendulum is a weight swinging on a string (C-2). The periodic table lists elements by atomic number (D-3).

Multiple choice

In summers, pendulum clock becomes

  1. faster

  2. slower

  3. stops

  4. random
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

If a metal wire is used in a pendulum, its length changes with temperature. During summers, its length increases and thus increasing its period and the pendulum clocks go slow in summer.

Multiple choice

Let a girl be swinging on a swing while she is in a sitting position. If she stands up now, how will the period of swing be effected?

  1. No change in time period

  2. It will increase

  3. It will decrease

  4. It will become zero
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When the girl stands up, the center of gravity of the swing system rises, effectively shortening the length of the pendulum (L). Since the time period T = 2 * pi * sqrt(L/g), a decrease in L results in a decrease in the time period.

Multiple choice

What is the amplitude of the oscillation?

  1. The maximum distance from the centre by which the pendulum moves.

  2. The time taken for one oscillation.

  3. It is the number of oscillations per second.

  4. The maximum distance from one end to another extreme the pendulum covers.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Yes, the more the push, the more the distance the pendulum  will cover from its central position, the more its amplitude.