Question

2 wires have their length in ratio 1:3 and radius in ratio 2:1. what will be the ratio of elongation for the same linear stress​

Answer 1

Explanation:

R=Aρl=πr2ρl

So,  R2R1=(πr22ρ2l2)(πr12ρ1l1)

R2R1=ρ2l2r12ρ1l1r22

But ρ2ρ1=12,l2l1