A Carnot engine operates between a source and a sink. The efficiency of the engine is $$40 \%$$ and the temperature of the sink is $$27^{\circ} \mathrm{C}$$. If the efficiency is to be increased to $$50 \%$$, then the temperature of the source must be increased by

A car engine has a power of 20 kW. The car makes a roundtrip of 1 h. If the thermal efficiency of the engine is $$40 \%$$ and the ambient temperature is 300 K . The energy generated by fuel combustion is

The number of vibrational degree of freedom of a diatomic molecule is

A glass vessel of volume $$V_o$$ is completely filled with a liquid and its temperature is raised by $$\Delta T$$. What volume of the liquid will flow over, if the coefficient of linear expansion of glass is $$\alpha_g$$ and coefficient of volume expansion of the liquid is $$\gamma_l$$ ?