Question

The increase in length of a wire on stretching is 0.025%. If its Poisson's ratio is 0.4, then the percentage decrease in diameter is:

• A. 0.01%
• B. 0.02%
• C. 0.03%
• D. 0.04%

Answer 1

The correct option is A 0.01%

Increase in length, $\frac{\Delta 1}{1}=0.025$%

$\frac{\Delta d}{d}=?$

Poisson’s ratio is $\mathrm{0.4.}$

$Poisso{n}^{\prime }sratio=\frac{\frac{\Delta d}{d}}{\frac{\Delta l}{l}}$

$0.4=\frac{\frac{\Delta d}{d}}{\frac{0.025}{100}}$

$\frac{\Delta d}{d}=\frac{0.4\times 0.025}{100}$

$\frac{\Delta d}{d}=0.01$ %

Then the percentage decrease $=0.01$ %.

Option A is correct.