Question

A stone of mass m is attached to one end of a wire of cross-sectional area A and young's modulus Y. The stone is revolved in a horizontal circle at a speed such that the wire makes an angle $\theta$ with the vertical. The strain produced in the wire will be,

• A.
• B.
• C.
• D.

Answer 1

The correct option is B

T cos$\theta$ = mg

$\Rightarrow$ T = $\frac{mg}{cos\theta }$

Increase in the length of wire is, $\Delta$l = $\frac{TL}{AY}$

Strain = $\frac{\Delta l}{L}$ = $\frac{mg}{AYcos\theta }$