In a sonometer wire, the tension is maintained by suspending a 50.7kg mass from the free end of the wire. The suspended mass has a volume of `0.0075m^(3)`. The fundamental frequency of the wire is 260Hz. If the suspended mass is completely submerged in water, the fundamental frequency will become (take `g= 10 ms^(-2)`)

Options

A. 240Hz
B. 230Hz
C. 220Hz
D. 200Hz

Answer

A

Explanation

Apparent weight when submerged in water
`=50.7 -0.0075 xx 1000`
`=50.7 - 7.5kg= 43.2kg`
Now as `v= (1)/(2l) sqrt((T)/(m)) :. (v_(2))/(v_(1)) = sqrt((T_(2))/(T_(1)))`
or `(v_(2))/(260) = sqrt((43.2)/(50.7)) :. V_(2) = 240Hz`