What will be the stress required to double the length of a wire of Young's modulus Y?

Options

A. `(Y)/(2)`
B. 2Y
C. Y
D. 4Y

Answer

C

Explanation

Let L be the length of the wire. If the length of the wire is doubled, the longitudinal strain will be `(Delta L)/(L) = (2L- L)/(L) =(L)/(L) =1`
As Young.s modulus `Y= ("Stress")/("Strain")`
`:.` Stress= Y (strain) = Y ( `:.` Strain =1)