Question

If the area of metal changes by 0.22% when it is heated through 10°C, then calculate the coefficient of superficial expansion.

Answer 1

\(\frac{ΔA}{A} =\)0.22% = \(= \frac {0.22}{100}\)

Change in temperature ΔT = 10°C

∴ Coefficient of cubical expansion

\(a_A = \frac{ΔA}{AΔT}\)

\(a_A = \frac{0.22}{100 \times 10} = 0.22 \times 10^{-3}\)

= 22 × 10 /°C