question_answer

In the following questions, Statement of assertion (A) is followed by a statement of reason (R).       1. If both assertion and reason are true and the reason is the correct explanation of the assertion, then mark. 2. If both assertion and reason are true but the reason is not the correct explanation of the assertion, then mark. 3. If assertion is true statement but reason is false, then mark. 4. If both assertion and reason are false statements then mark.

Assertion: The amplitude of an oscillating pendulum decreases gradually with time. Reason: The frequency of the pendulum decreases with time.

A)  1  

B)                                        2                            

C)        3                            

D)                        4

Correct Answer: C

Solution :

Oscillations damp down after some time, because of frictional forces acing on it. This is known as damping. Damping is the term used to describe the loss of energy with each cycle of a oscillation. This occurs because of loss of heat due to air resistance or frictional forces. However, fraction of energy lost is small. While frequency does not depend upon amplitude of oscillation;