Question

(i) What is meant by the terms amplitude and frequency of a wave?
(ii) Explain why stringed musical instruments, like the guitar, are provided with a hollow box.

Answer 1

(i) Amplitude : The maximum displacement on either side of the mean position of the vibrating particle is called amplitude.
Frequency : The number of vibration of particle performed by the wave in one second is called frequency of the wave.
(ii) Musical instruments like guitar are provided with a hollow box so that when the strings are set into vibration, forced vibrations are produced in box. Since the box has a large area, it sets a large volume of air into vibration which causes resonance to occur. This produces a loud sound of same frequency as that of the string.