Question

In sonometer, fundamental frequency changes from 400 Hz to 500 Hz keeping same tension. Find percentage change in length.

(1) 5% 

(2) 10% 

(3) 20% 

(4) 40%

Answer 1

Correct Option is (3) 20% 

f  = \(\frac{V}{2l_1}= 400\) 

\(\frac{v}{2l_2}= 500\) 

= 20%