Question

A glass flask is filled up to a mark with $50cc$of mercury at ${18}^{o}C$. If the flask and content are heated to ${38}^{o}C$, how much mercury will be above the mark? ($\alpha$ for glass is $9\times {10}^{-6}/C$ and coefficient of real expansion of mercury is $180\times {10}^{-6}/C)$

• A. $0.85cc$
• B. $0.46cc$
• C. $0.153cc$
• D. $0.05cc$

Answer 1

The correct option is C $0.153cc$

Volume expansion coefficient of glass$=3\times linear=3\alpha$

Change in temperature is $38-18={20}^{0}C$

Increment of volume of flask is $\Delta V=50cc\times 3\alpha \times {20}^{0}C=0.027cc$

Expansion in mercury $50cc\times \gamma \Delta t=50\times 180\times {10}^{-6}\times 20=0.180cc$

Apparent increment=$0.180-0.027=0.153cc$

Option C is correct.