A stone is attached to one end of a string and rotated in a vertical circle. If string breaks at the position of maximum tension, it will break at

Options

A. A
B. B
C. C
D. D

Answer

B

Explanation

The body is describing a vertical circle,
`therefore " " T -mg cos theta =(mv^(2))/(l)`
or `" " T =mg cos theta +(mv^(2))/(l)`
Tension is maximum when `costheta=1` and velocity is maximum . Both conditions are satisfied at `theta=0^@`
(i.e .at lowest points B)