If the volume of a block of metal changes by $0.12\%$ when it is heated through $20^o\,C$, the coefficient of linear expansion (in per $^oC^{-1}$) of the metal is :-

- A
$10^{-5}$

- B
$2 \times 10^{-5}$

- C
$3 \times 10^{-5}$

- D
$5 \times 10^{-5}$

$2\,g$ of steam condenses when passed through $40\,g$ of water initially at $25\,^oC$. The condensation of steam raises the temperature of water to $54.3\,^oC$, ........ $cal/g$ is the latent heat of steam ?

A rod of length $20 \,\,cm$ is made of metal. It expands by $0.075\,\, cm$ when its temperature is raised from $0^o C$ to $100^o C$. Another rod of a different metal $B$ having the same length expands by $0.045 cm$ for the same change in temperature, a third rod of the same length is composed of two parts one of metal $A$ and the other of metal $B$. Thus rod expand by $0.06 \,\,cm$.for the same change in temperature. The portion made of metal $A$ has the length .............. $cm$

Three perfect gases at absolute temperature $T_1 , T_2$ and $T_3$ are mixed. The masses of molecules are $m_1 , m_2$ and $m_3$ and the number of molecules are $n_1 , n_2$ and $n_3$ respectively. Assuming no loss of energy, the final temperature of the mixture is

A solid cube having certain fixed melting and boiling points takes heat from some source. The variation of temperature $\theta$ of the cube with the heat supplied $Q$ is shown in the adjoining graph. The portion $BC$ of the graph represents the conversion of

$1\, kg$ of ice at $-10\,^oC$ is mixed with $4.4\, kg$ of water at $30\,^oC$. The final temperature of mixture is ........ $^oC$ (specific heat of ice is $2100\, J/kg/k$)