A steel rod of length 1 m is heated from 25°C to 75°C while prevented from expanding. α=12×10⁻⁶ °C⁻¹. Magnitude of compressive strain is n×10⁻⁴. Find n.
Physics · Mixed Chapter
JEE Main Practice

Question

A steel rod of length 1 m is heated from 25°C to 75°C while prevented from expanding. α=12×10⁻⁶ °C⁻¹. Magnitude of compressive strain is n×10⁻⁴. Find n.

G1 Physics · Accepted Answer

Step 1: Free thermal strain would be ε=αΔT. Step 2: ΔT=75−25=50°C; ε=(12×10⁻⁶)×50=600×10⁻⁶. Step 3: ε=6×10⁻⁴, so n=6.