Question

The co-efficient of linear expansion of glass is $8\times {10}^{-6}{/}^{o}C$ and the co-efficient of real expansion of mercury is $180\times {10}^{-6}{/}^{0}C$. The co-efficient of apparent expansion of mercury in glass vessel is :

• A. $204\times {10}^{-6}{/}^{0}C$
• B. $7.5\times {10}^{-6}{/}^{0}C$
• C. $18\times {10}^{-5}{/}^{0}C$
• D. $156\times {10}^{-6}{/}^{0}C$

Answer 1

The correct option is D $156\times {10}^{-6}{/}^{0}C$

${\gamma }_a={\gamma }_r-{\gamma }_g$
${\gamma }_g=3{\alpha }_g=3\times 8\times {10}^{-6}$
$\therefore {\gamma }_a=180\times {10}^{-6}-24\times {10}^{-6}=$156 x ${10}^{-6}$