Entropy of a thermodynamic system does not change when this system is used for -

(1) Conduction of heat from a hot reservoir to a cold reservoir

(2) Conversion of heat into work isobarically

(3) Conversion of heat into internal energy isochorically

(4) Conversion of work into heat isochorically

Which is incorrect ?

(1) In an isobaric process, Δp = 0

(2) In an isochoric process, ΔW = 0

(3) In an isothermal process, ΔT = 0

(4) In an isothermal process, ΔQ = 0

A Carnot engine working between 300 K and 600K has work output of 800 J per cycle. What is amount of heat energy supplied to the engine from source per cycle ?

(1) 1800 J/cycle

(2) 1000 J/cycle

(3) 2000 J/cycle

(4) 1600 J/cycle

In a cyclic process, the internal energy of the gas:

For a reversible process, necessary condition is -

(1) In the whole cycle of the system, the loss of any type of heat energy should be zero

(2) That the process should be too fast

(3) That the process should be slow so that the working substance should remain in thermal and mechanical equilibrium with the surroundings

(4) The loss of energy should be zero and it should be quasistatic

A Carnot's engine used first an ideal monoatomic gas then an ideal diatomic gas. If the source and sink temperature are 411°C and 69°C respectively and the engine extracts 1000 J of heat in each cycle, then area enclosed by the PV diagram is -

(1) 100 J

(2) 300 J

(3) 500 J

(4) 700 J

The temperature of sink of Carnot engine is 27°C. Efficiency of engine is 25%. Then temperature of source is -

(1) 227°C

(2) 327°C

(3) 127°C

(4) 27°C

The temperature of reservoir of Carnot's engine operating with an efficiency of 70% is 1000K. The temperature of its sink is -

(1) 300 K

(2) 400 K

(3) 500 K

(4) 700 K

In a Carnot engine, when \(T_2=0^\circ \mathrm{C}\) and \(T_1=200^\circ \mathrm{C},\) its efficiency is \(\eta_1\) and when \(T_1=0^\circ \mathrm{C}\) and \(T_2=-200^\circ \mathrm{C},\) its efficiency is \(\eta_2.\) What is the value of \(\frac{\eta_1}{\eta_2}?\)

The efficiency of Carnot's engine operating between reservoirs, maintained at temperatures 27°C and –123°C, is 

(1) 50%

(2) 24%

(3) 0.75%

(4) 0.4%