A wire is stretched so that its longitudinal strain is 1.0 × 10⁻³. Its diameter decreases by 0.03%. If its Poisson ratio is N/100, find N.

Question

G1 Physics · Accepted Answer

Poisson ratio is ν = magnitude of transverse strain / longitudinal strain. Diameter decrease: 0.03% = 0.03/100 = 3×10⁻⁴. Therefore, ν = [3×10⁻⁴] / [1×10⁻³] = 0.30. The question gives ν = N/100. Thus, N/100 = 0.30. Hence, N = 30.