Assertion : Resonance is special case of force vibration in which the nature frequency of vebration of the body is the same as the impressed frequency of external periodic force and the amplitude of force vibration is maximum
Reason: The amplitude of forced vibrations of a bodyincrease with an increase in the frequency of the externally impressed perioic force

Options

A. If both assertion and reason are true and the reason is the correct explanation of the assertion.
B. If both assertion and reason are true but reason is not the correct explanation of the assertion.
C. If assertion is true but reason is false.
D. If the assertion and reason both are false

Answer

C

Explanation

Amplitude of oscillation for a forced, damped oscillator is `A=(F_(0)//m)/(sqrt((omega^(2)-omega_(0)^(2))+(bomega//m)^(2)))`, where b is constant related to the strength of the resistive force, `omega_(0)=sqrt(k//m)` is natural frequency of undamped oscillator (b=0).
When the frequency of driving force `(omega)~~omega_(0)`, then amplitude A is very larger.