Question

A sheet of brass is $100 cm$ long and $40 cm$ broad at 273 K. The area of the surface increase by $2 cm ^{2}$ at $100^{\circ} C$. What is the coefficient of linear expansion of brass?

• A. $5 \times 10^{-6}{ }^{\circ} C ^{-1}$
• B. $2.510^{-6}{ }^{\circ} C ^{-1}$
• C. $3 \times 10^{-6}{ }^{\circ} C ^{-1}$
• D. $2 \times 10^{-5 \circ} C ^{-1}$

Answer 1

Answer: (B)

$\frac{\Delta A }{ A _{ o } \Delta T }=\beta=\frac{2}{4000 \times 100}$
$=5 \times 10^{-6}{ }^{\circ} C ^{-1}$
$\alpha=\frac{\beta}{2}=2.5 \times 10^{-6} /{ }^{\circ} C$