In a thermocouple,if the thermo $EMF$ is given by $E = 40\theta - \frac{\theta^2}{20}$,then the neutral temperature will be .......... $^oC$.

$A$ steel ball of mass $0.1 \, kg$ falls freely from a height of $10 \, m$ and bounces to a height of $5.4 \, m$ from the ground. If the dissipated energy in this process is absorbed by the ball,the rise in its temperature is ........... $^\circ C$ (Specific heat of steel $= 460 \, J \, kg^{-1} \, ^\circ C^{-1}, \; g = 10 \, m \, s^{-2}$)

On which of the following four processes does the functioning of a bimetallic strip depend?
$(i)$ Radiation
$(ii)$ Energy conversion
$(iii)$ Melting
$(iv)$ Thermal expansion

$A$ geyser heats water flowing at the rate of $3.0 \, L/min$ from $27 \, ^{\circ}C$ to $77 \, ^{\circ}C$. If the geyser operates on a gas burner,what is the rate of consumption (in $g/min$) of the fuel if its heat of combustion is $4.0 \times 10^{4} \, J/g$?

$A$ steam engine intakes $50 \, g$ of steam at $100^{\circ} C$ per minute and cools it down to $20^{\circ} C$. If the latent heat of vaporization of steam is $540 \, cal \, g^{-1}$,then the heat rejected by the steam engine per minute is .........$\times 10^{3} \, cal$.

Work done in converting $1 \, g$ of ice at $-10^{\circ} C$ into steam at $100^{\circ} C$ is .......... $kJ$.