A pyknometer weight 40 g when empty and 1040g when filled with mercury at `0^(@)C`. On heating to `100^(@)C`, 10 g of mercury overflows. If the coefficient of real expansion of mercury is `0.0002//^(@)C`, the coefficient of expansion of glass is

Options

A. `0.00001//^(@)C`
B. `0.0002//^(@)C`
C. `0.0002//^(@)C`
D. `0.0001//^(@)C`

Answer

D

Explanation

Coefficient of real expansion, ` gamma_(real) = gamma _(apparent) + gamma_(g)`
`gamma_(app.) = ("Mass of expelled liquid")/"("Mass of remaining liquid "xx" Change in temperature")`
`implies gamma_(alpha) = (1000 - 990 )/(990 xx (100))`
`implies gamma_(alpha) = 0.01 xx 10^(-2//@)C`
` therefore gamma_(glass) = gamma_(real) - gamma_(apparent) = 0.0002 - 0.0001 = 0.0001//^(@)C`