Question

Two wires A and B are of same material. Their lengths are in the ratio 1:2 and diameters are in the ratio 2:1 when stretched byb force `F_A` and `F_B` respectively they get equal increase in their lengths. Then the ratio `(F_A)/(F_B)` should be
A. `1:2`
B. `1:1`
C. `2:1`
D. `8:1`

Answer 1

Correct Answer - D
`F=YxxAxx(l)/(L)impliesFprop(r^2)/(L)`
`(F_A)/(F_B)=((r_A)/(r_B))^2xx((L_B)/(L_A))=((2)/(1))^2xx((2)/(1))=(8)/(1)`