Question

Standing waves are produced in 10m long stretched string. If the string vibrates in 5 segments and wave velocity in 20m/s, the frequency is?

(a) 5Hz

(b) 10Hz

(c) 2Hz

(d) 4Hz

I had been asked this question in a national level competition.

The above asked question is from Beats topic in portion Waves of Engineering Physics I

Answer 1

The correct choice is (a) 5Hz

For explanation I would say: Frequency of standing waves in a stretched string,

vp=p/2l×√(T/m)=p/2l×v

vp=5/(2×10)×20=5Hz.