A particular force (F) applied on a wire increases its length by `2 xx 10^(-3)` m. To increases the wire's length by `4 xx 10^(-3)` m, the applied force will be

Options

A. 4F
B. 3F
C. 2F
D. F

Answer

c

Explanation

Young's modulus `Y= (F//A)/(I//L) = (F xx L)/(A xx I)`
Where, Y is young's modulus of elasticity)
since, Y, L and A remain same.
`F prop I implies (F_(1))/(F_(2)) = (I_(1))/(I_(2))`
`implies (F)/(F_(2)) = (2 xx 10^(-3))/(4 xx 10^(-3)) implies F_(2) = 2F`