Question

A crystal has a coefficient of expansion $13 \times 10^{-7}$ in one direction and $231 \times 10^{-7}$ in every direction at right angles to it. Then the cubical coefficient of expansion is

• A. $462 \times 10^{-7}$
• B. $244 \times 10^{-7}$
• C. $475 \times 10^{-7}$
• D. $257 \times 10^{-7}$

Answer 1

Answer: (C)

$ \gamma =\alpha_{1}+\alpha_{2}+\alpha_{3}$
$=13 \times 10^{-7}+231 \times 10^{-7}+231 \times 10^{-7}$
$=475 \times 10^{-7}$