A simple pendulum is made of a hollow sphere containing mercury suspended by means of a wire. If a little mercury is drained off, the period of the pendulum will:
Correct answer: B. increase:
- A. remain the same:
- B. increase:
- C. decrease
- D. B, C
Explanation
When only a little mercury is drained from the initially full sphere, the centre of gravity of the remaining mercury shifts downward, so the effective length L of the pendulum increases. Since T = 2π√(L/g), the period increases. (Only as the sphere nears empty does the centre of gravity rise again and the period fall; for a small amount drained the period increases.)
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
About Simple Harmonic Motion
Simple harmonic motion is oscillation in which acceleration is directly proportional to displacement and directed toward the equilibrium position. Work includes displacement, velocity, acceleration, phase, period, frequency, amplitude and energy, with applications to springs and simple pendulums. The restoring force and the conditions for SHM distinguish it from general periodic motion.
Practise Waves
1,281 free Waves MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Physics questions like this
Physics is on 16 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Simple Harmonic Motion questions
A body of mass 2 kg is hung on a spring balance mounted vertically in a lift moving upward with an acceleration of 2 m/s². The reading on the spring balance will be
If a pendulum is oscillating with a frequency f then what is the frequency at which it's K.E. changes?
For a stiff spring, the value of spring constant is:
A physical system undergoing forced vibrations is called:
The total energy of a simple harmonic motion at the mean position is:
The frequency for a second's pendulum is: