Which one of the following statements is true for a simple harmonic oscillator?
- A.Force acting is directly proportional to the displacement from the mean position and is in same direction.
- B.Force acting is directly proportional to the displacement from the mean position and is in opposite direction.
- C.Acceleration of the oscillator is constant.
- D.The velocity of the oscillator is not periodic.
Correct answer
Explanation
The correct answer is B, Force acting is directly proportional to the displacement from the mean position and is in opposite direction. This is the defining condition of simple harmonic motion, written F = −kx, where k is the force constant and the minus sign shows that the force always points back towards the mean position. Such a restoring force pulls the body back whenever it moves away, so it keeps swinging to and fro about the mean position. The acceleration is a = −(k/m)x, so it is largest at the extreme positions and zero at the mean position, while the speed is greatest at the mean position. Option A is wrong because a force in the same direction as the displacement would push the body further away, and it would never return. Option C is wrong because the acceleration changes with displacement all the time; it is not constant. Option D is wrong because the velocity repeats with the same period as the displacement, so it is periodic. Exam tip: SHM means F = −kx; acceleration is maximum at the extremes, speed is maximum at the mean position.
Practice Questions
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- B.5 cm
- C.2 cm
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- C.vegetables and fruits.
- D.soya bean and milk.
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- A.AgF
- B.AgBr
- C.AgCl
- D.Ag2SO4
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Read the full explanation →Which one of the following statements about speed and velocity is correct?
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- B.Speed and velocity both are scalar quantities.
- C.Speed is vector quantity and velocity is scalar quantity.
- D.Speed is scalar quantity and velocity is vector quantity.
Show answer
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