Question

A source produces 25 crests and 25 troughs in 0.2 seconds then the frequency of the wave is
a. 250 HZ
b. 300 HZ
c. 200 HZ
d.125 HZ
​

Answer 1

Given:

Time taken = 0.2 seconds

Number of crests produced = 25

Number of troughs produced = 25

To Find:

The frequency of the wave .

Solution :

One wave is formed by one crest and one trough .

The number of waves = 25 (25 crest + 25 trough)

Now ,

Frequency of a wave , ν  = Number of waves / Total time taken

=>  ν = 25 / 0.2

=>  ν = 125 Hz

The frequency of the given wave is 125 Hz .