Question

A source produces 60 crests and 60 troughs in 0.6 second. Then, the time period of the wave is ____ s.

Answer 1

Answer:

Solution  

Correct option is C)

Crest is a point of a wave where the displacement of swaying particles become maximum and Trough is a point of wave where displacement of swaying particles is minimum. The wave length is the distance between two closest crests or the distance between the two closest troughs. As we see 2 crests are related with one wavelength and 2 troughs are related with one wavelength. So if 40 crests and 40 troughs are there it means there are 40 wavelengths.

If 40 wavelengths produced in 0.4 seconds, then, 40 m/0.4 s wavelengths are produced in 1 second. Wavelengths produced per second is the frequency of the specific wave.

So the frequency of the sound is = 40 m/0.4 s = 100 Hz.

Explanation: