## Marks 1

Which one of the following pairs of equations describes an irreversible heat engine?

One kilogram of water at room temperature is brought into contact with a high temperature thermal reservoir. The entropy change of the universe is

If a closed system is undergoing an irreversible process, the entropy of the system

$$2$$ moles of oxygen are mixed adiabatically with another $$2$$ moles of oxygen in mixing chamber, so that the final total pressure and temperature o...

Which of the following relationships is valid only for reversible process undergone by a closed system of simple compressible substance (neglect chang...

For an ideal gas the expression $$\left[ {T{{\left( {{{\delta s} \over {\delta T}}} \right)}_p} - T{{\left( {{{\delta s} \over {\delta T}}} \right)}_v...

A system undergoes a state change from $$1$$ to $$2.$$ According to the second law of thermodynamics, for the process to be feasible, the entropy chan...

A $$1500$$ $$W$$ electrical heater is used to heat $$20$$ $$kg$$ of water $$\left( {{C_p} = 4186\,\,J/kg\,\,K} \right)$$ in an insulated bucket, from ...

The slopes of constant volume and constant pressure lines in the $$T$$-$$s$$ diagram are ___________ and ___________respectively.

When a system executes an irreversible cycle:

Which among the following relations is/are valid ONLY for reversible process undergone by a pure substance?

## Marks 2

One $$kg$$ of an ideal gas (gas constant $$R=287$$ $$J/kg$$-$$K$$) undergoes an irreversible process from state- $${\rm I}$$ ( $$1$$ bar, $$300$$ $$K$...

One kg of air ($${R = 287\,\,J/kg}$$-$$K$$) under goes irreversible process between equilibrium state $$1\,\,\left( {{{20}^ \circ }C,\,\,0.9\,\,{m^3}}...

A closed system contains $$10$$ $$kg$$ of saturated liquid ammonia at $${10^ \circ }C.$$ Heat addition required to convert the entire liquid into satu...

Two identical metal blocks $$L$$ and $$M$$ (specific heat $$=0.4$$ $$kJ/kg.K$$), each having a mass of $$5$$ $$kg,$$ are initially at $$313$$ $$K.$$ A...

An amount of $$100$$ $$kW$$ of heat is transferred through a wall in steady state. One side of the wall is maintained at $${127^ \circ }C$$ and the ot...

An ideal gas of mass $$m$$ and temperature $${T_1}$$ undergoes a reversible isothermal process from an initial pressure $${P_1}$$ to final pressure $$...

In an experimental set-up, air flows between two stations $$P$$ and $$Q$$ adiabatically. The direction of flow depends on the pressure and temperature...

In an experimental set-up, air flows between two stations $$P$$ and $$Q$$ adiabatically. The direction of flow depends on the pressure and temperature...

Consider the following two processes;
$$\left( {\rm I} \right)$$ A heat source at $$1200$$ $$K$$ loses $$2500$$ $$kJ$$ of heat to a sink at $$800$$ $...

A cycle device operates between three thermal reservoirs, as shown in the figure. Heat is transferred to/from the cyclic device. It is assumed that he...

A vapor absorption refrigeration system is a heat pump with three thermal reservoirs as shown in the figure. A refrigeration effect of $$100$$ $$W$$ i...

Considering the relationship $$TdS=dU+PdV$$ between the entropy $$(S),$$ internal energy $$(U),$$ pressure $$(P),$$temperature $$(T)$$ and volume $$(V...

Nitrogen gas (molecular weight $$28$$) is enclosed in a cylinder by a piston, at the initial condition of $$2$$ bar, $$298$$ $$K$$ and $$1\,\,{m^3}$$....

Nitrogen gas (molecular weight $$28$$) is enclosed in a cylinder by a piston, at the initial condition of $$2$$ bar, $$298$$ $$K$$ and $$1\,\,{m^3}$$....

One kilomole of an ideal gas is throttled from an initial pressure of $$0.5$$ $$MPa$$ to $$0.1$$ $$MPa.$$ The initial temperature is $$300$$ $$K.$$ Th...

Figure below shows a reversible heat engine $${E_R}$$ having heat interactions with three constant temperature systems. Calculate the thermal efficien...

## Marks 5

An iron cube at a temperature of $$400$$ deg $$C$$ is dropped into an insulated bath containing $$10$$ $$kg$$ water at $${25^ \circ }C.$$ The water fi...