Increase in length of a wire on stretching is 0.025%. If its poisson's ratio is 0.4, percentage decrease in diameter is:
0.03%
0.02%
0.01%
0.05%
∆ll=0.025100=2.5×10-4 -∆DD=σ×∆ll=0.4×2.5×10-4=10-4 -∆DD×100=0.01%