A continuous flow water heater (geyser) has an electrical power rating $= 2 \,\,kW$ and efficienty of conversion of electrical power into heat $ = 80 \%$. If water is flowing through the device at the rate of $100 \,\,cc/sec$, and the inlet temperature is $10^o C$, the outlet temperature will be ……. $^oC$ 

A $20 \,g$ bullet whose specific heat is $5000 \,J kg ^{\circ} C$ and moving at $2000 \,m / s$ plunges into a $1.0 \,kg$ block of wax whose specific heat is $3000 \,J kg ^{\circ} C$. Both bullet and wax are at $25^{\circ} C$ and assume that $(i)$ the bullet comes to rest in the wax and $(ii)$ all its kinetic energy goes into heating the wax. Thermal temperature of the wax $\left(\right.$ in $\left.^{\circ} C \right)$ is close to

$50 \,gm$ ice at $0°C$ in insulator vessel, $50g$ water of $100°C$ is mixed in it, then final temperature of the mixture is (neglect the heat loss)

$50 \,g$ ice at $0^{\circ} C$ is dropped into a calorimeter containing $100 \,g$ water at $30^{\circ} C$. If thermal capacity of calorimeter is zero then amount of ice left in the mixture at equilibrium is ………. $g$

$150 \,g$ of ice is mixed with $100 \,g$ of water at temperature $80^{\circ} C$. The latent heat of ice is $80 cal / g$ and the specific heat of water is $1 cal / g ^{\circ} C$. Assuming no heat loss to the environment, the amount of ice which does not melt is ……….. $g$