A metal block expands in volume by 0.12% when temperature rises 20°C. If linear expansion coefficient is x×10⁻⁵ °C⁻¹, find x.
Physics · Mixed Chapter
JEE Main Practice

Question

A metal block expands in volume by 0.12% when temperature rises 20°C. If linear expansion coefficient is x×10⁻⁵ °C⁻¹, find x.

G1 Physics · Accepted Answer

Step 1: For an isotropic solid, β≈3α. Step 2: ΔV/V=0.12%=0.0012, hence β=(0.0012)/20=6×10⁻⁵ °C⁻¹. Step 3: α=β/3=2×10⁻⁵ °C⁻¹. Therefore x=2.