Question

Two wires made of the same material and of same area of cross-section are 1 m and 2 m long respectively. If a force required to change the length of 1 m wire by 1 cm is `F_(1)`, the the force required to change the length of 2m wire by 1 cm will be
A. `F_(1)//4`
B. `F_(1)//2`
C. `F_(1)`
D. `2F_(1)`

Answer 1

Correct Answer - B
`F=(Yal)/(L), F_(1)=(YA)/(1)xx0.1 and F_(2)=(YA)/(2)xx0.1`
`therefore F_(2)=(F_(1))/(2)`