A fork gives 5 beats with a 40 cm length of sonometre wire. If the length of the wire is shortened by 1 cm, the number of beats is still the same. The frequency of the fork is :

A fork gives 5 beats with a 40 cm length of sonometre wire. If the len

1.	A fork gives 5 beats with a 40 cm length of sonometre wire. If the length of the wire is shortened by 1 cm, the number of beats is still the same. The frequency of the fork is :
Answer» 385 Hz 600 Hz 395 Hz 400 Hz Solution :Here v = `(1)/(2l)sqrt(T//m)` `THEREFORE "" v l ` = constant `therefore"" v_(1) l_(1)= v_(2) l_(2) `. If v be the FREQUENCY of TUNNING fork. `(v - 5) 40= (v + 5) 39 `. `rArr "" v = 395 ` Hz. Hence the correct CHOICE is (c).

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A fork gives 5 beats with a 40 cm length of sonometre wire. If the length of the wire is shortened by 1 cm, the number of beats is still the same. The frequency of the fork is :

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