The coefficient of linear expansion of a crystalline substance in one direction is 2 × 10-4 / ° C and in every direction perpendicular to it is 3 × 10-4 / ° C. The coefficient of cubical expansion of crystal is equal to

Question

The coefficient of linear expansion of a crystalline substance in one direction is 2 × 10-4 / ° C and in every direction perpendicular to it is 3 × 10-4 / ° C. The coefficient of cubical expansion of crystal is equal to (A) 5 ×10-4 / ° C (B) 4 × 10-4 / ° C (C) 8 × 10-4 / ° C (D) 7 × 10-4 / ° C

Tardigrade Admin · Accepted Answer

α1+α2+α3=α 2 × 10-4+3 × 10-4+3 × 10-4=α ⇒ 8 × 10-4 / ° C =α

Q. The coefficient of linear expansion of a crystalline substance in one direction is $2 \times 1 0^{- 4/^{\circ} C}$ and in every direction perpendicular to it is $3 \times 1 0^{- 4/^{\circ} C}$ . The coefficient of cubical expansion of crystal is equal to

$5 \times 1 0^{- 4} /^{\circ} C$

$4 \times 1 0^{- 4} /^{\circ} C$

$8 \times 1 0^{- 4} /^{\circ} C$

$7 \times 1 0^{- 4} /^{\circ} C$

$α_{1} + α_{2} + α_{3} = α$
$2 \times 1 0^{- 4} + 3 \times 1 0^{- 4} + 3 \times 1 0^{- 4} = α$
$\Rightarrow 8 \times 1 0^{- 4} /^{\circ} C = α$

Q. The coefficient of linear expansion of a crystalline substance in one direction is 2×10−4/∘C and in every direction perpendicular to it is 3×10−4/∘C. The coefficient of cubical expansion of crystal is equal to

5×10−4/∘C

4×10−4/∘C

8×10−4/∘C

7×10−4/∘C