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 general knowledge

What is the time period of simple pendulum at the centre of the earth?

  1. 24 Hours

  2. 9.8 Secs

  3. Infinite

  4. 1 Year
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

At the center of the Earth, the effective gravitational acceleration (g) becomes zero because the mass of the Earth is symmetrically distributed around that point, canceling out all gravitational forces. Since the time period formula T = 2π√(L/g) would result in division by zero, the time period becomes theoretically infinite.

Multiple choice general knowledge

A pendulum is taken to Moon , its time period will___________?

  1. Increase

  2. Decrease

  3. Remains same

  4. Depends on mass of Pendulum
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The time period of a simple pendulum is T = 2π√(L/g), where L is length and g is gravitational acceleration. The Moon's gravity is about 1/6th of Earth's gravity, so the denominator decreases, making T increase. The period does NOT depend on the mass of the pendulum bob.

Multiple choice general knowledge science & technology

For a pendulum, how does frequency vary with length

  1. The same way

  2. Inversely

  3. As a multiple

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

For a simple pendulum, frequency f = (1/2π)√(g/L), meaning frequency decreases as length increases. It's inversely proportional to the square root of length, so 'inversely' is the correct choice among the given options. A longer pendulum swings fewer times per second.

Multiple choice general knowledge science & technology

When the mass of a pendulum in a clock is increased, then

  1. The period increases and the clock loses time

  2. The period increases and the clock gains time

  3. The period decreases and the clock gains time

  4. The period remains constant and the clock maintains correct time
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The period of a simple pendulum depends only on its length (T = 2π√(L/g)) and is independent of mass. Changing the pendulum bob's mass doesn't affect the period, so the clock continues to keep correct time. The pendulum's timekeeping is based on length and gravity, not mass.

Multiple choice

The kinetic energy of a simple pendulum _____.

  1. never becomes zero

  2. becomes zero in each turn

  3. becomes zero in equilibrium case

  4. always remains the same
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

At the extreme positions of its swing (maximum amplitude), a simple pendulum momentarily comes to rest as it changes direction. At this point, its kinetic energy is zero. The kinetic energy then increases as it accelerates toward the lowest point, converting potential energy to kinetic energy.

Multiple choice

Time period of a simple pendulum depends upon _____.

  1. shape of the bob

  2. size of the bob

  3. length of the string

  4. density of the bob
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The time period of a simple pendulum is given by T = 2π√(L/g), where L is the length of the string and g is acceleration due to gravity. The time period depends only on the length and gravitational acceleration, not on the mass, shape, size, or density of the bob.

Multiple choice

If a pendulum clock is taken from the equator to the poles, it will _____.

  1. run slow

  2. run fast

  3. give the same time

  4. stop altogether
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The acceleration due to gravity (g) is higher at the poles than at the equator due to Earth's shape (oblate spheroid) and rotational effects. Since the time period of a pendulum is T = 2π√(L/g), a higher g means a shorter time period. The clock completes each swing faster, so it effectively runs slow (loses time) when compared to its rate at the equator.

Multiple choice

Which of the following statements is/are false? a. The amplitude of vibrations of a simple pendulum can be increased by raising the height from which the pendulum's bob is initially released. b. For a given pendulum, the time-period is the same every time. c. The time-period of a pendulum depends only on the amplitude of the vibrations and not on the length of the pendulum.

  1. Only a

  2. Only a and b

  3. Only b

  4. Only b and c

  5. Only c
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

This is a false statement. Thus, it is a correct option. The time-period of a pendulum depends only on the length of the pendulum and not on the amplitude of vibrations.

Multiple choice

Three pendulum clocks A, B and C are synchronized on the surface of the earth at the sea level. The clock A is taken to the top of a mountain and the clock B is taken under a deep mine. The temperatures at the three, locations are assumed to be the same. One the basic of the above, which one of the following is correct?

  1. Both A and B run faster than C

  2. Both A and B run slower than C

  3. A runs slower than C but runs faster than C

  4. B runs slower then C but A runs faster than C
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Pendulum period depends on gravity (T = 2π√(l/g)). At a mountain top, g is lower, so period increases (runs slower). In a deep mine, g is also lower due to mass being above, so period also increases (runs slower). Both A and B run slower than C.

Multiple choice

Which type of motion is exhibited by a simple pendulum?

  1. Random motion

  2. Oscillatory motion

  3. Circular motion

  4. Curvilinear motion

  5. Periodic motion
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Oscillatory motion: The 'to and fro' motion of a body, e.g. motion of a swing, movement of the 'bob' of a pendulum in a clock etc.

Multiple choice

The time period of a pendulum on moon

  1. remains the same

  2. decreases

  3. increases

  4. becomes zero
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The time period of a simple pendulum depends on gravitational acceleration (T = 2π√(L/g)). On the Moon, gravity is about 1/6th of Earth's gravity, so the pendulum swings slower and takes more time to complete one oscillation. The time period increases by a factor of √6.