Question

can anyone solve it.
plz show the process also.

Answer 1

Y = FL / (Ae)

For two steel wires Young’s modulus is same.
Given that same load is applied. F = same for both.
Hence, L / Ae = constant for both the wires.

So, 
e₂/e₁ = (L₂ / L₁) × (A₁/A₂)
e₂/e₁ = (L₂ / L₁) × (r₁ / r₂)²
e₂ = e₁ × (L₂/L₁) × (r₁ / r₂)²
e₂ = 1 mm × (5 / 4) × (4 / 3)²
e₂ = 2.22 mm

Increase in length of second wire is 2.22 mm