Question

A source of wave produces 20 crests and 20 troughs in 0.2 s . Find the frequency of the wave.

Answer 1

Find Time period and the frequency

One crest and a trough make a single wavelength.

So, 20 wavelengths are made according to the question.

Time = 0.2 seconds

Frequency = Number of waves / Time taken = 20 / 0.2 = 100 Hz

Time period = Time taken for The waves / Number of waves = 0.2 / 20 = 0.01 Second