A thermodynamic system is taken through the cycle PQRSP process. The net work done by the system is
20 J
-20 J
400 J
-374 J
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
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
A gas at state A changes to state B through path I and II shown in figure. The changes in internal energy are ΔU1 and ΔU2 respectively. Then
Δ U1 > ΔU2
Δ U1 < ΔU2
Δ U1 = ΔU2
Δ U1 = ΔU2 = 0
The PT diagram for an ideal gas is shown in the figure, where AC is an adiabatic process. Find the corresponding PV diagram.
110 J of heat is added to a gaseous system, whose internal energy is 40 J, then the amount of external work done is
150 J
70 J
110 J
40 J
The efficiency of Carnot engine is 50% and temperature of sink is 500 K. If the temperature of source is kept constant and its efficiency is to be raised to 60%, then the required temperature of the sink will be
600 K
500 K
400 K
100 K
5.6 litre of helium gas at STP is adiabatically compressed to 0.7 litre. Taking the initial temperature to be T1, the work done in the process is
An ideal mono atomic gas is taken round the cycle ABCDA as shown in the P-V diagram.
PV
2 PV
PV / 2
zero
When a system is taken from the initial state i to final state f along he path iaf, it is found that Q = 50 cal and W = 20 cal. If along the path ibf, Q = 36 cal, then W along the path ibf is
6 cal
16 cal
66 cal
14 cal
