Question

A tuning force priduces 4 beates per second with 2 oop's having length 30 and 31 cm find tgw frequency of t.f.

Answer 1

Let v be the frequency of tuning fork. 

Let, v₁ and v₂ be the frequencies of sonometer wire when its length is 30cm and 31 cm respectively. 

The frequency of sonometer wire is inversely proportional to the length of the sonometer wire. 

Therefore

v1/v₂=31/30  ......(1)

From the above equation, it is clear that v₁ > v₂ . Since tuning fork produces 4 beats per second with sonometer wire for both lengths, therefore

v₁>v₂

v₁-v=4

=> v₁=v+4

and v₁-v₂=4

=> v₂=v-4

thus, v₁/v₂=v+4/v-4  ......(2)

from (1) and (2)

v+4/v-4=31/30

(v+4)30=31(v-4)

After solving we get

v=244 Hz , is the frequency of the tuning fork.