$A$ geyser heats water flowing at a rate of $2.0 \; kg$ per minute from $30^{\circ} C$ to $70^{\circ} C$. If the geyser operates on a gas burner,the rate of combustion of fuel will be $\dots \; g \min^{-1}$.
[Heat of combustion $= 8 \times 10^{3} \; J \cdot g^{-1}$,Specific heat of water $= 4.2 \; J \cdot g^{-1} \cdot {}^{\circ} C^{-1}$]

$A$ lead bullet moving with velocity $V$ strikes a wall and stops. If $75 \%$ of its energy is converted into heat,then the increase in temperature is ($s=$ specific heat of lead,$J=$ mechanical equivalent of heat).

Fill in the blanks:
$1.$ The temperature of freezing point ...... and temperature of boiling point ...... are taken in a Fahrenheit thermometer.
$2.$ The zeroth law of thermodynamics defines ...... and the first law of thermodynamics defines ......
$3.$ At ...... temperature,water and water vapour have equal density.
$4.$ The ...... has the maximum value of specific heat.

$A$ piece of ice (heat capacity = $2100 \text{ J kg}^{-1} \text{ }^\circ\text{C}^{-1}$ and latent heat = $3.36 \times 10^5 \ J kg^{-1}$) of mass $m$ grams is at $-5^oC$ at atmospheric pressure. It is given $420 \ J$ of heat so that the ice starts melting. Finally, when the ice-water mixture is in equilibrium, it is found that $1 \ gm$ of ice has melted. Assuming there is no other heat exchange in the process, the value of $m$ is ...... $gm$.

Match the following List-$I$ with List-$II$.

List-$I$	List-$II$
$A$. When ice melts into water	$I$. Volume increases
$B$. When water changes into steam	$II$. Volume decreases
$C$. Melting point of ice	$III$. Increases with increase of pressure
$D$. Boiling point of water	$IV$. Decreases with increase in pressure

$A$ lead bullet of $20 \ g$ travelling at $300 \ m/s$ strikes against a block of wood and comes to rest. Assuming $50 \%$ of heat is absorbed by the bullet,the increase in its temperature is $.....^{\circ} C$ (take specific heat of lead $= 150 \ J/kg \cdot K$).