Page 7 - form 5 physics chapter 1

Resonance ¾ Resonance occurs when a system is made to oscillate
at a frequency equivalent to its natural frequency by an
external force. The resonating system oscillates at its
maximum amplitude.

Experiment ¾ The frequency of a simple pendulum depends on the

in Barton’s length of the pendulum.

pendulum ¾ In Barton’s pendulum experiment, there are many

pendulums tied to the rope. Two of the pendulum are of

the same length

¾ When pendulum B

oscillates, all the other

pendulums are forced to

oscillate.

How does ¾ But pendulum D

resonance oscillates with the largest

occur in amplitude, ie, pendulum

the two D resonates

pendulum ¾ Pendulum B and pendulum D are of the same length.
of equal ¾ Frequency B = Frequency D
length?
¾ Therefore, pendulum B causes pendulum D to oscillate

at its natural frequency.

Good 1. The tuner in a radio or television enables us to select

effects of the programmes we are interested. The circuit in the

resonance 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 3. A bridge can collapse when the amplitude of its

of vibration increases as a result of resonance.

resonance

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