Question

When a wire is subjected to a force along its length, its length increases by 0.4% and its radius decreases by 0.2%. Then the Poissons ratio of the material of the wire is

• A. 0.8
• B. 0.5
• C. 0.2
• D. 0.1

Answer 1

Answer: (B)

0.5

Answer 2

Poissons ratio ct is the ratio of fractional change in diameter to fractional change in length. Thus, $\sigma =\frac{\Delta r/r}{\Delta l/l}$ where r is the radius of the wire. $\therefore$ $\sigma =\frac{0.2}{0.4}$ $=0.5$