Question

There is no change in the volume of a wire due to change in its length on stretching. What is the possion's ratio of the material of the wire........... 

(A) + 0.5 

(B) – 0.50 

(C) 0.25 

(D) – 0.25

Answer 1

 Correct option: (A) + 0.5

Explanation:

(dV / V) = (1 – 2σ) ∙ (dL / L)

Given : There is no change in the volume of wire hence

(dV / V) = 0

i.e. 0 = (dL / L) (1 – 2σ)

i.e. 1 – 2σ = 0

i.e. 1 = 2σ     

i.e.      σ = (1/2) = 0.5