In Melde's experiment, the string vibrates in 4 loops when a 50 gram weight is placed in the pan of weight 15 gram . To make the string to vibrates in 6 loops the weight that has to be removed from the pan is

Options

A. 0.0007 kg wt
B. 0.0021 kg wt
C. 0.036 kg wt
D. 0.0029 kg wt

Answer

C

Explanation

`f=(n)/(2l)sqrt((T)/(mu)),impliesnsqrt(T)` = constant `implies(n_(1))/(n_(2))=sqrt((T_(2))/(T_(1)))`
`implies (4)/(6)=sqrt((T_(2))/((50+15)gm-"force"))`
`implies T_(2)=28.8gm` - force
Weight removed from the pan
`=T_(1)-T_(2)=65-28.8`
`=36.2gm` - force = 0.036kg - force