A Carnot engine, having an efficiency of 1/10 as a 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
100 J
The number of translational degree of freedom for a diatomic gas is:
2
3
5
6
An ideal monoatomic gas is taken round the cycle ABCDA as shown in the P-V diagram.
PV
2 PV
PV / 2
zero
A scientist says that the efficiency of his heat engine which works at source temperature of 127oC and sink temperature 27oC is 26%:
It is impossible
It is possible but less probable
It is quite possible
Data is incomplete
In an adiabatic system which is true ?
PγTγ-1 = constant
PγT1-γ = constant
PTγ = constant
P1-γTγ = constant
A Carnot engine whose sink is at 300 K has an efficiency of 40%. By how much should the temperature of the source be increased so as to increase its efficiency by 50% of original efficiency?
275 K
325 K
250 K
380 K
A gas is suddenly compressed to 1/4th of its original volume at normal temperature. The increase in its temperature (γ = 1.5) is:
273 K
573 K
373 K
473 K
A diatomic ideal gas is used in a Carnot engine as the working substance. If during the adiabatic expansion part of the cycle the volume of the has increased from V to 32 V, the efficiency of the engine is:
0.25
0.5
0.75
0.99
An ideal gas is compressed adiabatically to 8/27 times of its present value at 27oC. The temperature of the gas becomes: (γ= 5/3).
475oC
275oC
402oC
175oC
The molar specific heat at constant pressure of an ideal gas is (7/2)R. The ratio of specific heat at constant pressure to that at constant volume is
7/5
8/7
5/7
9/7
