The density of water at $20^oC$ is $0.998\, gm/cm^3$ and at $40^oC$ is $0.992\, gm/cm^3$. The mean coefficient of cubical expansion (in per $^oC$) is :-

- A
$1 \times 10^{-4}$

- B
$2 \times 10^{-4}$

- C
$3 \times 10^{-4}$

- D
$6 \times 10^{-4}$

$50\, gm$ of copper is heated to increase its temperature by $10\,^oC$. If the same quantity of heat is given to $10\, gm$ of water, the rise in its temperature is ........ $^oC$ (Specific heat of copper $=420\, Joule\, kg^{-1}\,^oC^{-1}$)

Maximum density of $H_2O$ is at temperature

A cylindrical metal rod of length $L_0$ is shaped into a ring with a small gap as shown. On heating the system

If the earth suddenly stops revolving and all its rotational $KE$ is used up in raising its temperature and if $'s'$ is taken to be the specific heat of the earth's material, the rise of temperature of the earth will be : ( $R -$ radius of the earth and $\omega =$ its angular velocity, $J =\,Joule$ constant)

A bimetallic strip consists of metals $X$ and $Y.$ It is mounted rigidly at the base as shown in the figure. The metal $X$ has a higher coefficient of expansion as compared to that for metal $Y.$ When the bimetallic strip is placed in a cold bath ?