Length of a simple pendulum Is 2 m and mass of its bob is 0.2 kg. If the tension in the string exceeds 4 N, it will break. If g=`10ms-^(-2)` and the bob is through which the sting can make with vertical during rotation is .

Options

A. `40^@`
B. `60^@`
C. `50^@`
D. `180^@`

Answer

B

Explanation

Given ,thension in the string , `T_(max)=4N `
Length of pendulum , l=2m
and mass of the bob =0.2 kg
The vertical component of T balances the height of the bob and the horizontal component procides the necessary centripetal force . Thus ,
`T lcostheta =mg " " therefore" costheta=(mg)/(T)`
On putting the value of all given variables ,We get
`cos theta =(0.2xx10)/(4)=1/2 therefore theta=60^@`