An adiabatic process is one in which

no heat enters or leaves the gas

the temperature of the gas changes

the change in internal energy is equal to the mechanical workdone

425 + Mcqs in Thermodynamics in Graduate Aptitude Test (GATE) Page 9 McqOptions

401.	According to Gay-Lussac law for a perfect gas, p/T = constant, if v is kept constant.
A.	True
B.	False
Answer» B. False

Discussion

402.	The efficiency of Stirling cycle is __________ Carnot cycle.
A.	greater than
B.	less than
C.	equal to
Answer» D.

Discussion

403.

Carbonisation of coal consists of

A.

drying and crushing the coal to a fine powder

B.

moulding the finely ground coal under pressure with or without a binding material

C.

heating the wood with a limited supply of air to temperature not less than 280°C

D.

none of the above

Answer» E.

Discussion

404.	The ratio of specific heat at constant pressure (c_p) and specific heat at constant volume (c_v) is
A.	equal to one
B.	less than one
C.	greater than one
D.	none of these
Answer» D. none of these

Discussion

405.	The atomic mass of oxygen is
A.	12
B.	14
C.	16
D.	32
Answer» D. 32

Discussion

406.	The entropy __________ in an irreversible cyclic process.
A.	remains constant
B.	decreases
C.	increases
Answer» D.

Discussion

407.

The efficiency of Diesel cycle approaches to Otto cycle efficiency when

A.

cut-off is increased

B.

cut-off is decreased

C.

cut-off is zero

D.

cut-off is constant

Answer» D. cut-off is constant

Discussion

408.	The compression ratio for petrol engines is
A.	3 to 6
B.	5 to 8
C.	15 to 20
D.	20 to 30
Answer» C. 15 to 20

Discussion

409.

The pressure exerted by an ideal gas is __________ of the kinetic energy of all the molecules contained in a unit volume of gas.

A.

one-half

B.

one-third

C.

two-third

D.

three-fourth

Answer» D. three-fourth

Discussion

410.	Workdone in a free expansion process is
A.	zero
B.	minimum
C.	maximum
D.	positive
Answer» B. minimum

Discussion

411.	Which of the following has the minimum atomic mass?
A.	Oxygen
B.	Sulphur
C.	Nitrogen
D.	Carbon
Answer» E.

Discussion

412.

The processes occuring in open system which permit the transfer of mass to and from the system, are known as

A.

flow processes

B.

non-flow processes

C.

adiabatic processes

D.

none of these

Answer» B. non-flow processes

Discussion

413.	Which of the following is the lightest and most volatile liquid fuel?
A.	Gasoline
B.	Kerosene
C.	Fuel oil
Answer» B. Kerosene

Discussion

414.	When the gas is heated at constant volume, the heat supplied increases the internal energy of the gas.
A.	True
B.	False
Answer» B. False

Discussion

415.	Water gas is obtained by passing air and a large amount of steam over waste coal at about 650°C.
A.	Correct
B.	Incorrect
Answer» C.

Discussion

416.	An adiabatic process is one in which
A.	no heat enters or leaves the gas
B.	the temperature of the gas changes
C.	the change in internal energy is equal to the mechanical workdone
D.	all of the above
Answer» E.

Discussion

417.	There is a loss of heat in an irreversible process.
A.	True
B.	False
Answer» B. False

Discussion

418.

The amount of heat required to raise the temperature of the unit mass of gas through one degree at constant volume, is called

A.

specific heat at constant volume

B.

specific heat at constant pressure

C.

kilo Joule

D.

none of these

Answer» B. specific heat at constant pressure

Discussion

419.	The efficiency and work ratio of a simple gas turbine cycle are
A.	low
B.	very low
C.	high
D.	very high
Answer» C. high

Discussion

420.	A cycle consisting of one constant pressure, one constant volume and two isentropic processes is known as
A.	Carnot cycle
B.	Stirling cycle
C.	Otto cycle
D.	Diesel cycle
Answer» E.

Discussion

421.

All the commercial liquid fuels are derived from natural petroleum (or crude oil).

A.

True

B.

False

Answer» B. False

Discussion

422.	A piston-cylinder device initially contains air at 150 kPa and 27°C. At this state, the volume is 400 litre. The mass of the piston is such that a 350 kPa pressure is required to move it. The air is now heated until its volume has doubled. Determine the total heat transferred to the air.
A.	747 kJ
B.	757 kJ
C.	767 kJ
D.	777 kJ
Answer» D. 777 kJ

Discussion

423.	Which of the following is mostly neglected while doing calculations for finding maximum work?
A.	KE
B.	PE
C.	both of the mentioned
D.	none of the mentioned
Answer» D. none of the mentioned

Discussion

424.	In an open system, for maximum work, the process must be entirely
A.	irreversible
B.	reversible
C.	adiabatic
D.	none of the mentioned
Answer» C. adiabatic

Discussion

425.	or a process from state 1 to state 2, heat transfer in a reversible process is given by
A.	Q for reversible=(To)*(S1-S2)
B.	Q for reversible=(To)*(S2-S1)
C.	Q for reversible=(To)/(S1-S2)
D.	Q for reversible=(To)/(S2-S1)
Answer» C. Q for reversible=(To)/(S1-S2)

Discussion

Explore topic-wise MCQs in Graduate Aptitude Test (GATE).

According to Gay-Lussac law for a perfect gas, p/T = constant, if v is kept constant.

The efficiency of Stirling cycle is __________ Carnot cycle.

Carbonisation of coal consists of

The ratio of specific heat at constant pressure (c_p) and specific heat at constant volume (c_v) is

The atomic mass of oxygen is

The entropy __________ in an irreversible cyclic process.

The efficiency of Diesel cycle approaches to Otto cycle efficiency when

The compression ratio for petrol engines is

The pressure exerted by an ideal gas is __________ of the kinetic energy of all the molecules contained in a unit volume of gas.

Workdone in a free expansion process is

Which of the following has the minimum atomic mass?

The processes occuring in open system which permit the transfer of mass to and from the system, are known as

Which of the following is the lightest and most volatile liquid fuel?

When the gas is heated at constant volume, the heat supplied increases the internal energy of the gas.

Water gas is obtained by passing air and a large amount of steam over waste coal at about 650°C.

An adiabatic process is one in which

There is a loss of heat in an irreversible process.

The amount of heat required to raise the temperature of the unit mass of gas through one degree at constant volume, is called

The efficiency and work ratio of a simple gas turbine cycle are

A cycle consisting of one constant pressure, one constant volume and two isentropic processes is known as

All the commercial liquid fuels are derived from natural petroleum (or crude oil).

A piston-cylinder device initially contains air at 150 kPa and 27°C. At this state, the volume is 400 litre. The mass of the piston is such that a 350 kPa pressure is required to move it. The air is now heated until its volume has doubled. Determine the total heat transferred to the air.

Which of the following is mostly neglected while doing calculations for finding maximum work?

In an open system, for maximum work, the process must be entirely

or a process from state 1 to state 2, heat transfer in a reversible process is given by

Explore topic-wise MCQs in Graduate Aptitude Test (GATE).

According to Gay-Lussac law for a perfect gas, p/T = constant, if v is kept constant.

The efficiency of Stirling cycle is __________ Carnot cycle.

Carbonisation of coal consists of

The ratio of specific heat at constant pressure (cp) and specific heat at constant volume (cv) is

The atomic mass of oxygen is

The entropy __________ in an irreversible cyclic process.

The efficiency of Diesel cycle approaches to Otto cycle efficiency when

The compression ratio for petrol engines is

The pressure exerted by an ideal gas is __________ of the kinetic energy of all the molecules contained in a unit volume of gas.

Workdone in a free expansion process is

Which of the following has the minimum atomic mass?

The processes occuring in open system which permit the transfer of mass to and from the system, are known as

Which of the following is the lightest and most volatile liquid fuel?

When the gas is heated at constant volume, the heat supplied increases the internal energy of the gas.

Water gas is obtained by passing air and a large amount of steam over waste coal at about 650°C.

An adiabatic process is one in which

There is a loss of heat in an irreversible process.

The amount of heat required to raise the temperature of the unit mass of gas through one degree at constant volume, is called

The efficiency and work ratio of a simple gas turbine cycle are

A cycle consisting of one constant pressure, one constant volume and two isentropic processes is known as

All the commercial liquid fuels are derived from natural petroleum (or crude oil).

A piston-cylinder device initially contains air at 150 kPa and 27°C. At this state, the volume is 400 litre. The mass of the piston is such that a 350 kPa pressure is required to move it. The air is now heated until its volume has doubled. Determine the total heat transferred to the air.

Which of the following is mostly neglected while doing calculations for finding maximum work?

In an open system, for maximum work, the process must be entirely

or a process from state 1 to state 2, heat transfer in a reversible process is given by

The ratio of specific heat at constant pressure (c_p) and specific heat at constant volume (c_v) is