Page 17 - WAVES

Resonance

Resonance occurs when a system is made to oscillate at a frequency equal to its natural frequency
by an external force.
The resonating system oscillates at its maximum amplitude.

Good Effects

1. The tuner in a radio or television enables us to select the programmes we are interested. The

circuit in the tuner is adjusted until resonance is achieved, at the frequency transmitted by a
particular station selected. Hence a strong electrical signal is produced.

2. The loudness of music produced by musical instruments such as the trumpet and flute is the
result of resonance in the air.

Bad Effects

1. A strong wind can cause a bridge to vibrate
at a frequency equal to its natural frequency.

The bridge will collapse as it vibrates with
maximum amplitude.

2. A soprano singer singing at
a frequency equal to the
natural frequency of

vibration of the glass.
Maximum vibration will cause the glass
Tacoma Bridge shattered into pieces.
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