Thermodynamics

Assertion : During rapid pumping of air in tyres, air inside the tyre is hotter than atmosphere air. Reason : Adiabatic process occurs at very high rate.

Assertion : Co-efficient of performance of a refrigerator always greater than one. Reason : In a refrigerator, heat is extracted from lower temperature reservoir.

Which of the following $P-V$ diagrams, best represents an isothermal process?

Assertion : Pressure $(P)$ versus 1/volume $(V)$ graph is straight line for adiabatic process. Reason : $P V=$ constant for adiabatic process.

For a refrigerator, heat absorbed from source is $800 \mathrm{~J}$ and heat supplied to sink is $500 \mathrm{~J}$. Then find the coefficient of performance

In an isobaric process, the work done by a diatomic gas is $10 \mathrm{~J}$, the heat given to the gas will be

Assertion : In adiabatic process change in internal energy is equal to work done on gas. Reason: In adiabatic process no heat exchange with surrounding.

A diatomic gas which has initial volume of 10 litre is isothermally compressed to $1 / 15^{\text {th }}$ of its original volume where initial pressure is $10^5 \mathrm{Pascal}$. If temperature is $27^{\circ} \mathrm{C}$…

A Carnot engine operates with source at $127^{\circ} \mathrm{C}$ and sink at $27^{\circ} \mathrm{C}$. If the source supplies $40 \mathrm{~kJ}$ of heat energy, the work done by the engine is

When an ideal monoatomic gas is heated at constant pressure, the fraction of the heat energy supplied which increases the internal energy of the gas is

Assertion : In an adiabatic process, change in internal energy of a gas is equal to work done on or by the gas in the process. Reason : Temperature of gas remains constant in an adiabatic process.

Assertion : In an isolated system the entropy increases. Reason : The process in an isolated system is adiabatic only.