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
In a adiabatic process, the state of a gas is changed from P1, V1, T1 to P2, V2, T2. Which of the following relations is correct ?
Which of the following is incorrect regarding the first law of thermodynamics ?
It introduces the concept of the internal energy
It introduces the concept of the entropy
It is not applicable to any cyclic process
It is restatement of the principle of conservation of energy
If cp and cv denote the specific heat of nitrogen per unit mass at constant pressure and constant volume respectively, then:
cp - cv = R/28
cp - cv = R/14
cp - cv = R
cp - cv = 28R
The efficiency of a Carnot engine operating between temperatures of 100oC and -23oC will be
An engine has an efficiency of 1/6. When the temperature of sink is reduced by 62oC, its efficiency is doubled. Temperature of the source is
Which statement is incorrect ?
All reversible cycles have same efficiency.
Reversible cycle has more efficiency than an irreversible one.
Carnot cycle is a reversible one.
Carnot cycle has the maximum efficiency of all the cycles.
100 g of water is heated from 30oC to 50oC. Ignoring the slight expansion of the water, the change in its internal energy is: (specific heat of water is 4184 J/kg/K)
A thermodynamic process is shown in the figure. The pressure and volumes corresponding to some points in the figure are
PA = 3 × 104 Pa, VA = 2 × 10-3 m3
PB = 8 × 104 Pa, VB = 5 × 10-3 m3
In process AB, 600 J of heat is added to the system and in process BC, 200 J of heat is added to the system. The change in internal energy of the system in process AC would be
The equation of state for 5g of oxygen at a pressure p and temperature T, when occupying a volume V, will be
pV = (5/32)RT
pV = 5 RT
pV = (5/2)RT
pV = (5/16)RT