A Carnot engine works between temperature 72°C and 27°C. The efficiency of the engine is
70 %
30 %
0 %
10 %
Boyle's law is applicable for an
adiabatic process
isothermal process
isobaric process
isochoric process
During adiabatic expansion, the volume of air increases by 4%. The percentage decrease in the pressure will be
3.2 %
5.6 %
1.5 %
4.8 %
Consider two containers P and Q containing identical gases at same temperature, pressure and volume. The gas in container P is compressed to half of its original volume isothermally while the gas in container Q is compressed to half of its original value adibatically. The ratio of final pressure of gas is
A refrigerator is driven by 1000 W electric motor having an efficiency of 60%. The refrigerator is considered as a reversible heat engine operating between 273 K and 303 K. Time required by it to freeze 32.5 kg of water at 0°C is. (Given, latent heat of fusion of ice = 336 × 103 J-kg-1 and heat lost may be neglected).
53 min 20 s
33 min 20 s
48 min 40 s
28 min 32 s
Work of 146 kJ is performed in order to compress one kilo mole of a gas adiabatically and in this process the temperature ofthe gas increases by 7° C. The gas is (R = 8.3 J mol-1 K-1 )
diatomic
triatomic
a mixture of monoatomic and diatomic
monoatomic
Consider an ideal gas confined in an isolated closed chamber. As the gas undergoes an adiabatic expansion, the average time of collision between molecules increases to Vq , where V is the volume of the gas. The value of q is
An ideal heat engine exhausting heat at 27° C is to have 25% efficiency. It must take heat at
127 °C
227° C
327° C
None of these
Two spherical soap bubbles of radii r1 and r2 in vacuum combine under isothermal conditions. The resulting bubble has a radius equal to