Which one of the following pairs of equations describes an irreversible heat engine?

&conint; Q < 0 and &conint; Q< 0T

&conint; Q > 0 and &conint; Q< 0T

&conint; Q < 0 and &conint; Q< 0T

&conint; Q > 0 and &conint; Q> 0T

&conint; Q < 0 and &conint; Q> 0T

Brake thermal efficiency of the three basic types of reciprocating engines commonly used in road vehicles are given in the increasing order as

2 Stroke SI engine, 4 Stroke CI engine, 4 Stroke SI engine

2 Stroke SI engine, 4 Stroke SI engine, 4 Stroke CI engine

2 Stroke SI engine, 4 Stroke CI engine, 4 Stroke SI engine

4 Stroke SI engine, 2 Stroke SI engine, 4 Stroke CI engine

4 Stroke CI engine, 4 Stroke SI engine, 2 Stroke SI engine

One kilogram of water at room temperature is brought into contact with a high temperature thermal reservoir. The entropy change of the universe is

equal to entropy change of the reservoir

equal to entropy change of water

BHP of a diesel engine can be increased by

increasing the pressure of intake air

increasing the temperature of intake air

increasing the density of intake air

decreasing the density of intake air

Water has a critical specific volume of 0.003155 m

may rise or fall depending on the amount of heat transferred

When wet steam flows through a throttle valve and remains wet at exit

Its temperature increases but quality decreases

Its temperature and quality increase

Its temperature decreases but quality increases

Its temperature increases but quality decreases

Its temperature and quality decrease

An insulated rigid vessel contains a mixture of fuel and air. The mixture is ignited by a minute spark. The contents of the vessel experience

Increase in temperature and pressure but decrease in energy

Increase in temperature, pressure and energy

Decrease in temperature, pressure and energy

Increase in temperature and pressure but no change in energy

Increase in temperature and pressure but decrease in energy

Constant pressure lines in the superheated region of the Mollier diagram will have

Both positive and negative slope

In Rankine cycle, regeneration results in higher efficiency because

total work delivered by the turbine increases

pressure inside the boiler increases

heat is added before steam enters the low pressure turbine

average temperature of heat addition in the boiler increases

total work delivered by the turbine increases

Which one of the following is NOT a necessary assumption for the air-standard Otto cycle?

The combustion process is a constant volume heat addition process.

All processes are internally reversible.

Intake and exhaust processes are constant volume heat rejection processes.

The combustion process is a constant volume heat addition process.

The working fluid is an ideal gas with constant specific heats.

248 + Mcqs in Thermodynamics Miscellaneous in Thermodynamics Page 3 McqOptions

101.	An automobile engine operates at a fuel air ratio of 0.05, volumetric efficiency of 90% and indicated thermal efficiency of 30%. Given that the calorific value of the fuel is 45 MJ/kg and the density of air at intake in 1 kg/m
A.	6.075 bar
B.	6.75 bar
C.	67.5 bar
D.	243 bar
Answer» B. 6.75 bar

Discussion

102.	An amount of 100 kW of heat is transferred through a wall in steady State. One side of the wall is maintained at 127 C and the other side at 27 C. The entropy generated (in W/K) due to the heat transfer through the wall is ______.
A.	83.33 W / K
B.	82.33 W / K
C.	80.33 W / K
D.	84.33 W / K
Answer» B. 82.33 W / K

Discussion

103.	Which one of the following pairs of equations describes an irreversible heat engine?
A.	<table><tr><td rowspan="2">&conint; Q > 0 and &conint;</td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> Q</center></td><td rowspan="2">< 0</td></tr><td align="center">T</td></table>
B.	<table><tr><td rowspan="2">&conint; Q < 0 and &conint;</td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> Q</center></td><td rowspan="2">< 0</td></tr><td align="center">T</td></table>
C.	<table><tr><td rowspan="2">&conint; Q > 0 and &conint;</td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> Q</center></td><td rowspan="2">> 0</td></tr><td align="center">T</td></table>
D.	<table><tr><td rowspan="2">&conint; Q < 0 and &conint;</td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> Q</center></td><td rowspan="2">> 0</td></tr><td align="center">T</td></table>
Answer» B. <table><tr><td rowspan="2">&conint; Q < 0 and &conint;</td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;"><center> Q</center></td><td rowspan="2">< 0</td></tr><td align="center">T</td></table>

Discussion

104.	If the pressure at station Q is 50 kPa, the change in entropy (s
A.	0.155
B.	0
C.	0.160
D.	0.355
Answer» D. 0.355

Discussion

105.	Brake thermal efficiency of the three basic types of reciprocating engines commonly used in road vehicles are given in the increasing order as
A.	2 Stroke SI engine, 4 Stroke SI engine, 4 Stroke CI engine
B.	2 Stroke SI engine, 4 Stroke CI engine, 4 Stroke SI engine
C.	4 Stroke SI engine, 2 Stroke SI engine, 4 Stroke CI engine
D.	4 Stroke CI engine, 4 Stroke SI engine, 2 Stroke SI engine
Answer» B. 2 Stroke SI engine, 4 Stroke CI engine, 4 Stroke SI engine

Discussion

106.	One kg of air (R = 287 J/kgK) undergoes an irreversible process between equilibrium state 1 (20 C, 0.9 m
A.	- 116.36 J /kgK
B.	116.36 J /kgK
C.	- 117.36 J /kgK
D.	116.36 J /kgK
Answer» B. 116.36 J /kgK

Discussion

107.	A closed system contains 10kg of saturated liquid ammonia at 10 C. Heat addition required to convert the entire liquid into saturated vapour at a constant pressure is 16.2 MJ. If the entropy of the saturated liquid is 0.88 kJ/kgK, the entropy (in kJ/kgK) of saturated vapour is____
A.	6.6013 kJ/kg
B.	5.6013 kJ/kg
C.	7.6013 kJ/kg
D.	8.6013 kJ/kg
Answer» B. 5.6013 kJ/kg

Discussion

108.	An ideal gas of mass m and temperature T
A.	<table><tr><td rowspan="2">mRln</td><td rowspan="2"><img src="https://www.indiabix.com/_files/images/aptitude/1-sym-oparen-h1.gif"></td><td rowspan="2"></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;">P<sub>2</sub></td><td rowspan="2"></td><td rowspan="2"><img src="https://www.indiabix.com/_files/images/data-interpretation/common/15-sym-cparen-h1.gif"></td><td rowspan="2"></td> </tr><tr><td style="text-align: center;">P<sub>1</sub></td></tr></table>
B.	<table><tr><td rowspan="2">mRln</td><td rowspan="2"><img src="https://www.indiabix.com/_files/images/aptitude/1-sym-oparen-h1.gif"></td><td rowspan="2"></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;">P<sub>1</sub></td><td rowspan="2"></td><td rowspan="2"><img src="https://www.indiabix.com/_files/images/data-interpretation/common/15-sym-cparen-h1.gif"></td><td rowspan="2"></td> </tr><tr><td style="text-align: center;">P<sub>2</sub></td></tr></table>
C.	<table><tr><td rowspan="2">mRln</td><td rowspan="2"><img src="https://www.indiabix.com/_files/images/aptitude/1-sym-oparen-h1.gif"></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;">P<sub>2</sub></td><td rowspan="2"><img src="https://www.indiabix.com/_files/images/data-interpretation/common/15-sym-cparen-h1.gif"> </td><td rowspan="2">-</td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;">Q</td><td rowspan="2"></td></tr><tr><td style="text-align: center;">P<sub>1</sub></td><td style="text-align: center;">T<sub>1</sub></td></tr></table>
D.	Zero
Answer» C. <table><tr><td rowspan="2">mRln</td><td rowspan="2"><img src="https://www.indiabix.com/_files/images/aptitude/1-sym-oparen-h1.gif"></td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;">P<sub>2</sub></td><td rowspan="2"><img src="https://www.indiabix.com/_files/images/data-interpretation/common/15-sym-cparen-h1.gif"> </td><td rowspan="2">-</td><td style="border-bottom:1px solid #000000;vertical-align:bottom;padding-bottom:2px;">Q</td><td rowspan="2"></td></tr><tr><td style="text-align: center;">P<sub>1</sub></td><td style="text-align: center;">T<sub>1</sub></td></tr></table>

Discussion

109.	If the air has to flow from station P to station Q, the maximum possible value of pressure in kPa at station Q is close to
A.	50
B.	87
C.	128
D.	150
Answer» C. 128

Discussion

110.	One kilogram of water at room temperature is brought into contact with a high temperature thermal reservoir. The entropy change of the universe is
A.	equal to entropy change of the reservoir
B.	equal to entropy change of water
C.	equal to zero
D.	always positive
Answer» E.

Discussion

111.	A rope-brake dynamometer attached to the crank shaft of an I.C. engine measures a brake power of 10 kW when the speed of rotation of the shaft is 400 rad/s. The shaft torque (in Nm) sensed by the dynamometer is _____.
A.	25 N-m
B.	26 N-m
C.	35 N-m
D.	24 N-m
Answer» B. 26 N-m

Discussion

112.	A turbocharged four-stroke direct injection diesel engine has a displacement volume of 0.0259 m
A.	2
B.	1
C.	0.2
D.	0.1
Answer» B. 1

Discussion

113.	BHP of a diesel engine can be increased by
A.	increasing the pressure of intake air
B.	increasing the temperature of intake air
C.	increasing the density of intake air
D.	decreasing the density of intake air
E.	A and C both
Answer» F.

Discussion

114.	Propane (C
A.	14.29%
B.	13.29%
C.	17.29%
D.	15.29%
Answer» B. 13.29%

Discussion

115.	A steam power plant has the boiler efficiency of 92%, turbine efficiency (mechanical) of 94%, generator efficiency of 95% and cycle efficiency of 44%. If 6% of the generated power is used to run the auxiliaries, the overall plant efficiency is
A.	34%
B.	39%
C.	45%
D.	30%
Answer» B. 39%

Discussion

116.	If one mole of H
A.	83.14 Pascal
B.	82.14 Pascal
C.	81.14 Pascal
D.	84.14 Pascal
Answer» B. 82.14 Pascal

Discussion

117.	2 moles of oxygen are mixed adiabatically with another 2 moles of oxygen in a mixing chamber, so that the final total pressure and temperature of the mixtures become same as those of the individual constituents at their initial states. The universal gas constant is given as R. The change in entropy due to mixing, per mole of oxygen, is given by
A.	- Rln2
B.	0
C.	Rln2
D.	Pln4
Answer» C. Rln2

Discussion

118.	Water has a critical specific volume of 0.003155 m
A.	will rise
B.	will fall
C.	will remain constant
D.	may rise or fall depending on the amount of heat transferred
Answer» B. will fall

Discussion

119.	One kg of an ideal gas (gas constant R = 287 J/ kgK) undergoes an irreversible process from state-1 (1 bar, 300 K) to state-2 (2 bar, 300 K). The change in specific entropy (s
A.	- 198.93 J/kg K
B.	198.93 J/kg K
C.	199.93 J/kg K
D.	- 199.93 J/kg K
Answer» B. 198.93 J/kg K

Discussion

120.	One kg of an ideal gas (gas constant, R= 400 J/ kgK; specific heat at constant volume, c
A.	287.68 J/K
B.	187.68 J/K
C.	387.68 J/K
D.	277.68 J/K
Answer» B. 187.68 J/K

Discussion

121.	When wet steam flows through a throttle valve and remains wet at exit
A.	Its temperature and quality increase
B.	Its temperature decreases but quality increases
C.	Its temperature increases but quality decreases
D.	Its temperature and quality decrease
Answer» C. Its temperature increases but quality decreases

Discussion

122.	An insulated rigid vessel contains a mixture of fuel and air. The mixture is ignited by a minute spark. The contents of the vessel experience
A.	Increase in temperature, pressure and energy
B.	Decrease in temperature, pressure and energy
C.	Increase in temperature and pressure but no change in energy
D.	Increase in temperature and pressure but decrease in energy
Answer» D. Increase in temperature and pressure but decrease in energy

Discussion

123.	Constant pressure lines in the superheated region of the Mollier diagram will have
A.	A positive slope
B.	A negative slope
C.	Zero slope
D.	Both positive and negative slope
Answer» B. A negative slope

Discussion

124.	The pressure, temperature and velocity of air flowing in pipe are 5 bar, 500 K and 50 m/s, respectively. The specific heats of air at a constant pressure and at constant volume are 1.005 kJ/kgK and 0.718 kJ/kgK, respectively. Neglect potential energy. If the pressure and temperature of the surroundings are 1 bar and 300 K, respectively, the available energy in kJ/ kg of the air stream is
A.	170
B.	187
C.	191
D.	213
Answer» C. 191

Discussion

125.	Which of the following statements are TRUE with respect to heat and work?
A.	both (i) and (ii)
B.	both (i) and (iii)
C.	both (ii) and (iii)
D.	only(iii)
Answer» C. both (ii) and (iii)

Discussion

126.	The relationship ( T / P)
A.	An ideal gas at any state
B.	A real gas at any state
C.	Any gas at its critical state
D.	Any gas at its inversion point
E.	A and B both
Answer» F.

Discussion

127.	A tank of volume 0.05 m
A.	s = 2.4884 kJ/kg-K
B.	s = 1.4884 kJ/kg-K
C.	s = 3.4884 kJ/kg-K
D.	s = 4.4884 kJ/kg-K
Answer» B. s = 1.4884 kJ/kg-K

Discussion

128.	Water flowing at the rate of 1 kg/s through a system is heated using an electric heater such that the specific enthalpy of the water increases by 2.50 kJ/kg and the specific entropy increases by 0.007 kJ/kg.K. The power input t o t he electric heater is 2.50 kW. There is no other work or heat interaction between the system and the surroundings. Assuming an ambient temperature of 300 K, the irreversibility rate of the system is ____ kW (round off to two decimal places)
A.	i = 2.1 kW
B.	i = 3.1 kW
C.	i = 1.1 kW
D.	i = 0.1 kW
Answer» B. i = 3.1 kW

Discussion

129.	One side of a wall is maintained at 400 K and the other at 300 K. The rate of heat transfer through the wall is 1000 W and the surrounding temperature is 25 C. Assuming no generation of heat within the wall, the irreversibility (in W) due to heat transfer through the wall is.
A.	248.33 watt.
B.	246.33 watt.
C.	247.33 watt.
D.	249.33 watt.
Answer» B. 246.33 watt.

Discussion

130.	The maximum theoretical work obtainable, when a system interacts to equilibrium with a reference environment, is called
A.	Entropy
B.	Enthalpy
C.	Exergy
D.	Rothalpy
Answer» D. Rothalpy

Discussion

131.	The specific heats of an ideal gas depend on its
A.	Temperature
B.	Pressure
C.	Volume
D.	Molecular weight and structure
Answer» B. Pressure

Discussion

132.	During a non-flow thermodynamic process (1 2) execut ed by a per fect gas, t he heat interaction is equal to the work interaction (Q
A.	Adiabatic
B.	Polytropic
C.	Isothermal
D.	Isentropic
Answer» D. Isentropic

Discussion

133.	1.5 kg of water is in saturated liquid state at 2 bar (v
A.	4158
B.	4258
C.	5158
D.	4168
Answer» B. 4258

Discussion

134.	A steel billet of 2000 kg mass is to be cooled from 1250 K to 450 K. The heat released during this process is to be used as a source of energy. The ambient temperature is 303 K and specific heat of steel is 0.5 kJ/kgK. The available energy of this billet is
A.	490.44 MJ
B.	30.95 MJ
C.	10.35 MJ
D.	0.10 MJ
Answer» B. 30.95 MJ

Discussion

135.	The specific enthalpy data are in columns
A.	3 and 7
B.	3 and 8
C.	5 and 7
D.	5 and.8
Answer» E.

Discussion

136.	The compression ratio of a gas power plant cycle corresponding to maximum work output for the given temperature limits of T
A.	<img src="http://images.interviewmania.com/wp-content/uploads/2019/10/1a.png">
B.	<img src="http://images.interviewmania.com/wp-content/uploads/2019/10/1b.png">
C.	<img src="http://images.interviewmania.com/wp-content/uploads/2019/10/1c.png">
D.	<img src="http://images.interviewmania.com/wp-content/uploads/2019/10/1d.png">
Answer» B. <img src="http://images.interviewmania.com/wp-content/uploads/2019/10/1b.png">

Discussion

137.	In a gas turbine, hot combustion products with the specific heats c
A.	689.64 kJ/kg
B.	794.66 kJ/kg
C.	1009.72 kJ/kg
D.	1312.00 kJ/kg
Answer» B. 794.66 kJ/kg

Discussion

138.	In Rankine cycle, regeneration results in higher efficiency because
A.	pressure inside the boiler increases
B.	heat is added before steam enters the low pressure turbine
C.	average temperature of heat addition in the boiler increases
D.	total work delivered by the turbine increases
Answer» D. total work delivered by the turbine increases

Discussion

139.	The enthalpy at the pump discharge (h
A.	0.33 kJ/kg
B.	3.33 kJ/kg
C.	4.0 kJ/kg
D.	33.3 kJ/kg
Answer» E.

Discussion

140.	The thermal efficiency of the plant neglecting pump work is
A.	15.8%
B.	41.1%
C.	48.5%
D.	58.6%
Answer» C. 48.5%

Discussion

141.	Select statement from List-II matching the processes in List-I. Enter your answer as A, B is the correct choice for (1) is (A) and (2) and (B).
A.	C and B
B.	A and B
C.	C and A
D.	A and D
Answer» B. A and B

Discussion

142.	A vehicle powered by a spark ignition engine follows air standard Otto cycle ( = 1.4). The engine generates 70 kW while consuming 10.3 kg/hr of fuel. The calorific value of fuel is 44000 kJ/kg. The compression ratio is (correct to two decimal places).
A.	= 8
B.	= 8.61
C.	= 7.61
D.	= 9
Answer» D. = 9

Discussion

143.	when saturated liquid at 40 C is throttled to 20 C, the quality at exit will be
A.	0.189
B.	0.212
C.	0.231
D.	0.788
Answer» C. 0.231

Discussion

144.	Which one of the following is NOT a necessary assumption for the air-standard Otto cycle?
A.	All processes are internally reversible.
B.	Intake and exhaust processes are constant volume heat rejection processes.
C.	The combustion process is a constant volume heat addition process.
D.	The working fluid is an ideal gas with constant specific heats.
Answer» C. The combustion process is a constant volume heat addition process.

Discussion

145.	Heat supplied (kJ kg
A.	2372
B.	2576
C.	2863
D.	3092
Answer» E.

Discussion

146.	The net work output (kJ kg
A.	498
B.	775
C.	860
D.	957
Answer» B. 775

Discussion

147.	Which combination of the following statements is correct?
A.	P and S
B.	Q and S
C.	P, R and S
D.	P, Q, R and S
Answer» C. P, R and S

Discussion

148.	In a compression ignition engine, the inlet air pressure is 1 bar and the pressure at the end of isentropic compression is 32.42 bar. The expansion ratio is 8. Assuming ratio of specific heats ( ) as 1.4, the air standard efficiency (in percent) is
A.	59.59%
B.	59.699%
C.	59.599%
D.	59.99%
Answer» D. 59.99%

Discussion

149.	A diesel engine has a compression ratio of 17 and cut-off takes place at 10% of the stroke. Assuming ratio of specific heats ( ) and the air standard efficiency (in%) is .
A.	59.60%
B.	56%
C.	59%
D.	60%
Answer» B. 56%

Discussion

150.	In an air-standard Otto cycle, air is supplied at 0.1 MPa and 308 K. The ratio of the specific heats ( ) and the specific gas constant (R) of air are 1.4 and 288.8 J/kgK, respectively. If the compression ratio is 8 and the maximum temperature in the cycle is 2660 K, the heat (in kJ/kg) supplied to the engine is ______.
A.	1418
B.	1416.39
C.	1416.27
D.	1416
Answer» D. 1416

Discussion

Explore topic-wise MCQs in Thermodynamics.

An automobile engine operates at a fuel air ratio of 0.05, volumetric efficiency of 90% and indicated thermal efficiency of 30%. Given that the calorific value of the fuel is 45 MJ/kg and the density of air at intake in 1 kg/m

An amount of 100 kW of heat is transferred through a wall in steady State. One side of the wall is maintained at 127 C and the other side at 27 C. The entropy generated (in W/K) due to the heat transfer through the wall is ______.

Which one of the following pairs of equations describes an irreversible heat engine?

If the pressure at station Q is 50 kPa, the change in entropy (s

Brake thermal efficiency of the three basic types of reciprocating engines commonly used in road vehicles are given in the increasing order as

One kg of air (R = 287 J/kgK) undergoes an irreversible process between equilibrium state 1 (20 C, 0.9 m

A closed system contains 10kg of saturated liquid ammonia at 10 C. Heat addition required to convert the entire liquid into saturated vapour at a constant pressure is 16.2 MJ. If the entropy of the saturated liquid is 0.88 kJ/kgK, the entropy (in kJ/kgK) of saturated vapour is____

An ideal gas of mass m and temperature T

If the air has to flow from station P to station Q, the maximum possible value of pressure in kPa at station Q is close to

One kilogram of water at room temperature is brought into contact with a high temperature thermal reservoir. The entropy change of the universe is

A rope-brake dynamometer attached to the crank shaft of an I.C. engine measures a brake power of 10 kW when the speed of rotation of the shaft is 400 rad/s. The shaft torque (in Nm) sensed by the dynamometer is _____.

A turbocharged four-stroke direct injection diesel engine has a displacement volume of 0.0259 m

BHP of a diesel engine can be increased by

Propane (C

A steam power plant has the boiler efficiency of 92%, turbine efficiency (mechanical) of 94%, generator efficiency of 95% and cycle efficiency of 44%. If 6% of the generated power is used to run the auxiliaries, the overall plant efficiency is

If one mole of H

Water has a critical specific volume of 0.003155 m

One kg of an ideal gas (gas constant R = 287 J/ kgK) undergoes an irreversible process from state-1 (1 bar, 300 K) to state-2 (2 bar, 300 K). The change in specific entropy (s

One kg of an ideal gas (gas constant, R= 400 J/ kgK; specific heat at constant volume, c

When wet steam flows through a throttle valve and remains wet at exit

An insulated rigid vessel contains a mixture of fuel and air. The mixture is ignited by a minute spark. The contents of the vessel experience

Constant pressure lines in the superheated region of the Mollier diagram will have

Which of the following statements are TRUE with respect to heat and work?

The relationship ( T / P)

A tank of volume 0.05 m

One side of a wall is maintained at 400 K and the other at 300 K. The rate of heat transfer through the wall is 1000 W and the surrounding temperature is 25 C. Assuming no generation of heat within the wall, the irreversibility (in W) due to heat transfer through the wall is.

The maximum theoretical work obtainable, when a system interacts to equilibrium with a reference environment, is called

The specific heats of an ideal gas depend on its

During a non-flow thermodynamic process (1 2) execut ed by a per fect gas, t he heat interaction is equal to the work interaction (Q

1.5 kg of water is in saturated liquid state at 2 bar (v

A steel billet of 2000 kg mass is to be cooled from 1250 K to 450 K. The heat released during this process is to be used as a source of energy. The ambient temperature is 303 K and specific heat of steel is 0.5 kJ/kgK. The available energy of this billet is

The specific enthalpy data are in columns

The compression ratio of a gas power plant cycle corresponding to maximum work output for the given temperature limits of T

In a gas turbine, hot combustion products with the specific heats c

In Rankine cycle, regeneration results in higher efficiency because

The enthalpy at the pump discharge (h

The thermal efficiency of the plant neglecting pump work is

Select statement from List-II matching the processes in List-I. Enter your answer as A, B is the correct choice for (1) is (A) and (2) and (B).

A vehicle powered by a spark ignition engine follows air standard Otto cycle ( = 1.4). The engine generates 70 kW while consuming 10.3 kg/hr of fuel. The calorific value of fuel is 44000 kJ/kg. The compression ratio is (correct to two decimal places).

when saturated liquid at 40 C is throttled to 20 C, the quality at exit will be

Which one of the following is NOT a necessary assumption for the air-standard Otto cycle?

Heat supplied (kJ kg

The net work output (kJ kg

Which combination of the following statements is correct?

In a compression ignition engine, the inlet air pressure is 1 bar and the pressure at the end of isentropic compression is 32.42 bar. The expansion ratio is 8. Assuming ratio of specific heats ( ) as 1.4, the air standard efficiency (in percent) is

A diesel engine has a compression ratio of 17 and cut-off takes place at 10% of the stroke. Assuming ratio of specific heats ( ) and the air standard efficiency (in%) is .