The following four wires of length L and radius 'r' are made of the same material which of these will have largest extension ?

Options

A. L = 40 cm, r = 0.02 mm
B. L = 100 cm, r = 0.5 mm
C. L = 200 cm, r = 1 mm
D. L = 300 cm, r = 1.5 mm

Answer

A

Explanation

`Y=(F.L)/(pi r^(2)l) or Delta prop (L)/(r^(2))`
Here `L//r^(2)` is maximum when L = 40 cm and r = 0.20 mm as compared to other.