Thermodynamic processes are indicated in the following diagram.

Match the following

• P → a, Q → c, R → d, S → b

• P → c, Q → a, R → d, S → b

• P → c, Q → d, R → b, S → a

• P → c, Q → d, R → b, S → a

Carnot engine having an efficiency of 1/10 as heat engine, is used as a refrigerator. If the work done on the system is 10 J, the amount of energy absorbed from the reservoir at lower temperature is

• 1 J

• 90 J

• 99 J

• 99 J

A small sphere of radius 'r' falls from rest in a viscous liquid. As a result, heat is produced due to viscous force. The rate of production of heat when the sphere attains its terminal velocity, is proportional to

• r³

• r²

• r⁴

• r⁵

A sample of 0.1 g of water at 100°C and normal pressure (1.013 × 105 Nm^–2) requires 54 cal of heat energy to convert to steam at 100°C. If the volume of the steam produced is 167.1 cc, the change in internal energy of the sample, is

• 104.3 J

• 208.7 J

• 84.5 J

• 42.2 J

The volume (V) of a monatomic gas varies with its temperature (T), as shown in the graph. The ratio of work done by the gas, to the heat absorbed by it, when it undergoes a change from state A to state B, is

• 2/5

• 2/3

• 2/7

• 1/3

106.

The efficiency of an ideal heat engine working between the freezing point and boiling point of water, is

• 26.8%

• 20%

• 12.5%

• 6.25%

p-V plots for two gases during the adiabatic process as shown in figure plots 1 and 2 should correspond respectively to

• He and O₂

• O₂ and He

• He and Ar

• O₂ and N₂

The temperature of source and sink of a heat engine are 127^oC and 27^oC, respectively. An inventor claims its efficiency to be 26%, then 

• It is impossible

• It is possible with high probability

• It is possible with low probability

• Data are insufficient

Air is expanded from 50 litres to 150 litres at atmosphere the external work done is (1 atmospheric pressure =1$\times$${10}^5\mathrm{N}/{\mathrm{m}}^2$)

• $2\times {10}^{-8}\mathrm{J}$

• $2\times {10}^4\mathrm{J}$

• 200J

• 2000J

Helium at 27⁰C has a volume 8 litres. it is suddenly compressed to a volume of 1 litre. The temperature of the gas will be $\left(\mathrm{V}= \frac{5}{3}\right)$

• 9327⁰C

• 1200⁰C

• 927⁰C

• 108⁰C