The time period of a simple pendulum does not depend on which of the following?
- A.The length of the pendulum
- B.The mass of the bob
- C.The acceleration due to gravity
- D.All of these
Correct answer
Explanation
The correct answer is B, the mass of the bob. The time period of a simple pendulum is two pi times the square root of the length divided by g, in which the mass of the bob does not appear at all; a heavy bob and a light bob of the same length keep the same time, which is the law of mass. Option A is wrong because the period varies as the square root of the length, so a longer pendulum swings more slowly. Option C is wrong because the period varies inversely as the square root of g, which is why the same pendulum is slower on the moon and faster at the poles. Option D is wrong because two of the three quantities do affect the period. Note also the law of isochronism: for small oscillations the period does not depend on the amplitude either.
Read the full article: Oscillations: Simple Harmonic Motion and Pendulum Notes
Practice Questions
View allIf a particle is moving with simple harmonic motion, the velocity is _________ at the mean position.
- A.Maximum
- B.Zero
- C.Minimum
- D.None of these
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In simple harmonic motion the velocity is given by omega times the square root of A squared minus x squared.
Read the full explanation →A child is sitting on a swing. Its minimum and maximum heights from the ground are 0.75 m and 2 m respectively. Its maximum speed will be
- A.10 m/s
- B.5 m/s
- C.8 m/s
- D.15 m/s
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A swing is a pendulum, and its speed is greatest at the lowest point, where all the potential energy gained at the top has turned into kinetic energy.
Read the full explanation →The length of a second's pendulum, at a place where the acceleration due to gravity is 9.8 m/s squared, is nearly
- A.1 metre
- B.2 metres
- C.0.5 metre
- D.9.8 metres
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A second's pendulum is one whose time period is exactly two seconds, so that each swing from one side to the other takes one second.
Read the full explanation →If the length of a simple pendulum is made four times its original value, its time period will become
- A.Four times
- B.Two times
- C.Half
- D.One fourth
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The time period varies as the square root of the length, so multiplying the length by four multiplies the period by the square root of four, that is by two; to double the period of a pendulum its length must be made four times.
Read the full explanation →If a pendulum clock is taken from the earth to the moon, where the acceleration due to gravity is about one sixth, its time period will
- A.Decrease
- B.Increase
- C.Remain the same
- D.Become zero
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The time period varies inversely as the square root of g, so if g falls to one sixth, the period is multiplied by the square root of six, about 2.45 times; the pendulum swings more slowly and a pendulum clock taken to the moon would lose time badly.
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