Question

Assertion (A) In SHM, acceleration is always directed towards the mean position.

Reason (R) In SHM, the body has to stop momentary at the extreme position and move back to mean position. (NCERT Pg. 267)

• A. Both A and R are true and R is the correct explanation of A.
• B. Both A and R are true but R is NOT the correct explanation of A.
• C. A is true but R is false.
• D. A is false but R is true.

Answer 1

Answer: (B)

Both A and R are true but R is NOT the correct explanation of A.

Answer 2

Assertion (A): In Simple Harmonic Motion (SHM), the restoring force is always directed towards the mean position, and acceleration is in the direction of the force. Therefore, Assertion (A) is true.

Reason (R): At extreme positions, the velocity of the oscillating body momentarily becomes zero before it reverses direction due to the restoring force. Therefore, Reason (R) is true.

However, Reason (R) describes a kinematic consequence of SHM, while Assertion (A) describes a fundamental dynamic property. The stopping and turning back at extreme positions are a result of the acceleration being directed towards the mean position, not the reason for it. Therefore, Reason (R) does not correctly explain Assertion (A).