A one-metre long stretched string having a mass of 40 g is attached to a tuning fork. The fork vibrates at 128 Hz in a direction perpendicular to the string. What should be the tension in the string if it is to vibrate in four loops ?

Answer

A, D

Explanation

A string of mass 40 g is attached to the tuning fork
`m=(40xx10^3)kg/m`
The fork vibrates with
`f=128Hz`
`lamda=0.5m`
`v=flamda=128xx0.5`
`=64m/s`
`v=sqrt((T/m))`
`rarr T=v^2m`
`=(64)^2xx40xx10^-3`
`=163.84~~164N`