Q.When a body being acted by an external periodic force, vibrates with the frequency of the force, then the vibrations of the body are called ................ vibrations.

At resonance the amplitude is maximum. Answer (C).

Resonance occurs when the frequency of the periodic driving force equals the natural frequency of the system. At this condition energy is transferred to the oscillator most efficiently, and the ampli …

Vibrations at the frequency of an applied external force are called forced vibrations.

Every oscillating system has a natural frequency at which it vibrates if displaced and released. If instead an external periodic force continuously drives it, after the initial transient dies out the body settles into vibrating at the frequency of the applied force (not its own natural frequency) — these sustained oscillation …

Forced vibrations are driven vibrations whose frequency matches the driving force, not the system's natural frequency.

When a body capable of oscillating is subjected to a repeatedly applied (periodic) external force, it is initially disturbed and, after transients die out, it settles into oscillating at the frequency of the applied force itself — not necessarily its own natural frequency. These sustained, externally-driven oscillations are calle …

A forced vibration occurs when an external periodic driving force keeps a body oscillating at the driving frequency rather than its own natural frequency.

Every body has a natural frequency at which it vibrates freely once disturbed and left alone (free vibration). If, instead, an external periodic force is continuously applied to the body, the body is compelled to vibrate at the frequency of that applied force rather than its own natural frequency. This is called forced vibration.

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