Wave Mechanics Question 602

Question: A particle, with restoring force proportional to displacement and resisting force proportional to velocity is subjected to a force F sin $ \omega t $ . If the amplitude of the particle is maximum for $ \omega ={\omega _{1}} $ and the energy of the particle is maximum for $ \omega ={\omega _{2}} $ , then

Options:

A) $ {\omega _{1}}={\omega _{2}},and,{\omega _{2}}\ne {\omega _{0}} $

B) $ {\omega _{1}}={\omega _{0}},and,{\omega _{2}}={\omega _{0}} $

C) $ {\omega _{1}}\ne {\omega _{0}},and,{\omega _{2}}={\omega _{0}} $

D) $ {\omega _{1}}\ne {\omega _{0}},and,{\omega _{2}}\ne {\omega _{0}} $

Show Answer

Answer:

Correct Answer: C

Solution:

[c] At maximum energy of the particle, velocity resonance takes place, which occurs when frequency of external periodic force is equal to natural frequency of undamped natural vibrations, i.e. $ {\omega _{2}}\ne {\omega _{0}} $ . Further amplitude resonance takes place at a frequency of external force which is less than the frequency of undamped natural vibrations, i.e. $ {\omega _{1}}\ne {\omega _{0}} $ .