Question

Graph below shows variation of amplitude of forced oscillation with respect to frequency of driving force (natural frequency). Choose the correct statement(s).

• A. Amplitude is maximum at $\omega_{d}=\omega$.
• B. Peak amplitude is maximum for curve $a$ because for curve $a$ damping is minimum.
• C. Both (a) and (b)
• D. None of the above

Answer 1

Answer: (C)

From the given figure, amplitude is maximum when $\frac{\omega_{d}}{\omega}=1$, i.e. $\omega_{d}=\omega$. Also the peak of amplitude is maximum for curve $a$ which has least damping. With further increase in damping, amplitude decreases.