JEE Main 2023 · 15 April · morning · Single correct · +4 / −1

In a linear Simple Harmonic Motion (SHM)
(A) Restoring force is directly proportional to the displacement.
(B) The acceleration and displacement are opposite in direction.
(C) The velocity is maximum at mean position.
(D) The acceleration is minimum at extreme points.
Choose the correct answer from the options given below:

  1. (a) (A), (B) and (D) only
  2. (b) (C) and (D) only
  3. (c) (A), (B) and (C) Only
  4. (d) (A), (C) and (D) only
Answer and solution

Answer (c) (A), (B) and (C) Only

Solution

Physics sir · 2 steps

Everything in SHM follows from one line, a = -ω² x: check each statement against it.

  1. Start from the definition. Linear SHM means the restoring force is F = -kx. Dividing by mass gives the acceleration, and the velocity follows from energy.

    a = -ω² x, v = ω√(A² - x²)

    StatementCheck with the equationsVerdict
    (A) Force proportional to displacement|F| = k|x|True
    (B) Acceleration opposite to displacementThe minus sign in a = -ω² xTrue
    (C) Velocity maximum at mean positionAt x = 0, v = ω A, the largest valueTrue
    (D) Acceleration minimum at extremesAt x = ± A, |a| = ω² A, the largest valueFalse
  2. So. (A), (B) and (C) are correct and (D) is wrong, which is option (c).

The idea to keep. In SHM, speed and acceleration swap roles: speed is largest at the mean position and zero at the extremes, while acceleration is zero at the mean position and largest at the extremes.

Answer from the NTA final answer key. Solution by PrepWiser.

Study Simple Harmonic Motion

Asked about 130 times in JEE Main since 2020. This question is from 2023.