A wire is stretched by `2xx10^(-2)`m due to the force of 10 N. Then the amount of work done to stretch the wire to a displacement of `4xx10^(-2)`m is

Options

A. 0.04 J
B. 0.4 J
C. 40 J
D. 400 J

Answer

B

Explanation

`W_(1) =(1)/(2) Fl=(1)/(2)xx10 xx 2 xx 10^(-2) =0.1J`
`(W_(2))/(W_(1))=((l_(2))/(l_(1)))^(2)=((4xx10^(-2))/(2xx10^(-2)))^(2)=4`
`W_(2)=4W_(1)`
`=4xx0.1=0.4J`.