A blacksmith fixes iron ring on the rim of the wooden wheel of a horse cart. The diameter of the rim and the iron ring are $5.243\; m$ and $5.231\; m$, respectively at $27^oC$. To what temperature (in $^oC$) should the ring be heated so as to fit the rim of the wheel?

A rail track made of steel having length $10\,m$ is clamped on a railway line at its two ends as shown in figure. On a summer day due to rise in temperature by $20\,^oC$ , it is deformed as shown in figure. Find $x$ (displacement of the centre) if  $\alpha _{steel} = 1.2 \times 10^{-5} \,^oC^{-1}$

A beaker of height $H$ is made up of a material whose coefficient of linear thermal expansion is $3\alpha $ . It is filled up to the brim by a liquid whose coefficient of thermal expansion is $\alpha $. If now the beaker along with its contents is uniformly heated through a small temperature $T$ the level of liquid will reduce by (given $\alpha  << 1$) 

A copper rod of length $l_1$ and an iron rod of length $l_2$ are always maintained at the same common temperature $T$. If the difference $(l_2 -l_1)$ is $15\,cm$ and is independent of the value of $T,$ the $l_1$ and $l_2$ have the values (given the linear coefficient of expansion for copper and iron are $2.0 \times 10^{-6}\,C^{-1}$ and $1.0\times10^{-6}\,C^{ -1}$  respectively)

Two rods are joined between fixed supports as shown in the figure. Condition for no change in the lengths of individual rods with the increase of temperature will be

( ${\alpha _1},\,{\alpha _2},$ = linear expansion coefficient

$A_1, A_2$ = Area of rods

$Y_1, Y_2$ = Young modulus)

A piece of metal weight $46\, gm$ in air, when it is immersed in the liquid of specific gravity $1.24$ at $27°C$ it weighs $30\, gm.$ When the temperature of liquid is raised to $42°C$ the metal piece weight $30.5\, gm,$ specific gravity of the liquid at $42°C$ is $1.20,$ then the linear expansion of the metal will be