Question

Resonance is an example of
(A) Tuning fork
(B) Forced vibration
(C) Free vibration
(D) Damped vibration

Answer 1

Hint: Forced vibration is when an alternating force or motion is applied to a mechanical system, for example when a washing machine shakes due to an imbalance. Forced vibration is a type of vibration in which a force is repeatedly applied to a mechanical system.

Complete answer:
Resonance can occur only if external force is applied at the same frequency as that of natural frequency, Resonance describes the phenomenon of increased amplitude that occurs when the frequency of a periodically applied force is equal or close to a natural frequency of the system on which it acts, hence it is forced vibration.
Forced vibration occurs when the object is forced to vibrate at a particular frequency by a periodic input of force. If an object is being forced to vibrate at its natural frequency, resonance will occur and large amplitude vibration can be observed.
Resonance is used to increase the intensity of a sound. The comparatively weak vibrations produced at the end of an organ pipe.

So, the correct answer is “Option B”.

Additional Information:
Conditions to avoid resonance are adding stiffness and increasing the natural frequency. Adding mass decreases the natural frequency, increasing damping reduces the peak response but widens the response range, decreasing damping increases the peak response but narrows the response range.

Note:
Free vibration is a vibration in which energy is neither added to nor removed from the vibrating body. Resonant frequencies can also be disastrous if you build up too much vibrational energy in a system that can’t handle it, which is how sound alone at just the right pitch is capable of causing a wine glass of shatter.