4791 + Mcqs in Mechanical Engineering Page 50 McqOptions

2451.	According to Regnault's law, the specific heat at constant pressure (cp) and specific heat at constant volume (cv) __________ with the change in pressure and temperature of the gas.
A.	change
B.	do not change
Answer» C.

Discussion

2452.	In an extensive property of a thermodynamic system
A.	extensive heat is transferred
B.	extensive work is done
C.	extensive energy is utilised
D.	none of these
Answer» E.

Discussion

2453.	When a gas is heated at constant pressure
A.	its temperature will increase
B.	its volume will increase
C.	both temperature and volume will increase
D.	neither temperature not volume will increase
Answer» D. neither temperature not volume will increase

Discussion

2454.	Wood charcoal is produced by heating the wood at 100 C.
A.	Yes
B.	No
Answer» C.

Discussion

2455.	Equal volumes of all gases, at the same temperature and pressure, contain equal number of molecules. This statement is called Avogadro's law.
A.	True
B.	False
Answer» B. False

Discussion

2456.	The atomic mass of an element is the number of times the atom of that element is heavier than the hydrogen atom.
A.	True
B.	False
Answer» B. False

Discussion

2457.	For the same maximum pressure and temperature,
A.	Otto cycle is more efficient than Diesel cycle
B.	Diesel cycle is more efficient than Otto cycle
C.	Dual cycle is more efficient than Otto and Diesel cycles
D.	Dual cycle is less efficient than Otto and Diesel cycles
Answer» C. Dual cycle is more efficient than Otto and Diesel cycles

Discussion

2458.	In a steady flow process, the rate of
A.	heat transfer is constant
B.	work transfer is constant
C.	mass flow at inlet and outlet is same
D.	all of these
Answer» E.

Discussion

2459.	The entropy of the universe is continually on the increase.
A.	Correct
B.	Incorrect
Answer» B. Incorrect

Discussion

2460.	Which of the following process can be made reversible with the help of a regenerator?
A.	Constant pressure process
B.	Constant volume process
C.	Constant pvn process
D.	all of these
Answer» E.

Discussion

2461.	A cycle consisting of two isothermal and two isentropic processes, is known as
A.	Carnot cycle
B.	Stirling cycle
C.	Ericsson cycle
D.	Joule cycle
Answer» B. Stirling cycle

Discussion

2462.	The unit of energy is S. I. units is
A.	Joule (J)
B.	Joule metre (Jm)
C.	Watt(W)
D.	Joule/metre (J/m)
Answer» B. Joule metre (Jm)

Discussion

2463.	As per Charles' law, the volume of a given mass of a perfect gas varies __________ as its absolute temperature, when the absolute pressure remains constant.
A.	directly
B.	indirectly
Answer» B. indirectly

Discussion

2464.	Liquid fuels have lower efficiency than solid fuels.
A.	True
B.	False
Answer» C.

Discussion

2465.	Liquid fuels consist of hydrocarbons.
A.	True
B.	False
Answer» B. False

Discussion

2466.	Ericsson cycle consists of two constant pressure and two isothermal processes.
A.	Agree
B.	Disagree
Answer» B. Disagree

Discussion

2467.	One kg of carbon produces __________ kg of carbon dioxide.
A.	3/7
B.	7/3
C.	11/3
D.	3/11
Answer» D. 3/11

Discussion

2468.	The expansion ratio (r) is the ratio of (where v1 = Volume at the beginning of expansion, and v2 = Volume at the end of expansion)
A.	<img src="/_files/images/mechanical-engineering/thermodynamics/243-118-1.png">
B.	<img src="/_files/images/mechanical-engineering/thermodynamics/243-118-2.png">
C.	<img src="/_files/images/mechanical-engineering/thermodynamics/243-118-3.png">
D.	<img src="/_files/images/mechanical-engineering/thermodynamics/243-118-4.png">
Answer» C. <img src="/_files/images/mechanical-engineering/thermodynamics/243-118-3.png">

Discussion

2469.	The isothermal and isentropic processes are reversible non-flow processes.
A.	Agree
B.	Disagree
Answer» B. Disagree

Discussion

2470.	The blast furnace gas is a by-product in the production of pig iron in the blast furnace.
A.	Yes
B.	No
Answer» B. No

Discussion

2471.	Which is the incorrect statement about Carnot cycle?
A.	It is used as the alternate standard of comparison of all heat engines.
B.	All the heat engines are based on Carnot cycle.
C.	It provides concept of maximising work output between the two temperature limits.
D.	all of the above
Answer» C. It provides concept of maximising work output between the two temperature limits.

Discussion

2472.	When two bodies are in thermal equilibrium with a third body, they are also in thermal equilibrium with each other. This statement is called
A.	Zeroth law of thermodynamics
B.	First law of thermodynamics
C.	Second law of thermodynamics
D.	Kelvin Planck's law
Answer» B. First law of thermodynamics

Discussion

2473.	The area under the temperature-entropy curve (T - s curve) of any thermodynamic process represents
A.	heat absorbed
B.	heat rejected
C.	either (a) or (b)
D.	none of these
Answer» D. none of these

Discussion

2474.	The heating of a gas at constant pressure is governed by Charles' law.
A.	True
B.	False
Answer» B. False

Discussion

2475.	The area under the temperature-entropy curve (i. e. T - s curve) of any thermodynamic process represents the workdone during the process.
A.	Agree
B.	Disagree
Answer» C.

Discussion

2476.	A closed system is one in which heat and work crosses the boundary of the system but the mass of the working substance does not crosses the boundary of the system.
A.	Yes
B.	No
Answer» B. No

Discussion

2477.	The dual combustion cycle consists of one constant pressure, two constant volume and two isentropic processes.
A.	Agree
B.	Disagree
Answer» B. Disagree

Discussion

2478.	The specific heat at constant volume is
A.	the amount of heat required to raise the temperature of unit mass of gas through one degree, at constant pressure
B.	the amount of heat required to raise the temperature of unit mass of gas through one degree, at constant volume
C.	the amount of heat required to raise the temperature of 1 kg of water through one degree
D.	any one of the above
Answer» C. the amount of heat required to raise the temperature of 1 kg of water through one degree

Discussion

2479.	According to kinetic theory of gases, the velocity of molecules __________ with the increase in temperature.
A.	remains constant
B.	increases
C.	decreases
Answer» C. decreases

Discussion

2480.	The hard coke is obtained when carbonisation of coal is carried out at
A.	300 to 500 C
B.	500 to700 C
C.	700 to 900 C
D.	900 to 1100 C
Answer» E.

Discussion

2481.	According to First law of thermodynamics,
A.	total internal energy of a system during a process remains constant
B.	total energy of a system remains constant
C.	workdone by a system is equal to the heat transferred by the system
D.	internal energy, enthalpy and entropy during a process remains constant
Answer» C. workdone by a system is equal to the heat transferred by the system

Discussion

2482.	The root mean square velocity of the gas molecules is given by (where k = Boltzmann's constant, T = Absolute temperature, and m = Mass of one molecule of a gas)
A.	<img src="/_files/images/mechanical-engineering/thermodynamics/247-163-1.png">
B.	<img src="/_files/images/mechanical-engineering/thermodynamics/247-163-2.png">
C.	<img src="/_files/images/mechanical-engineering/thermodynamics/247-163-3.png">
D.	<img src="/_files/images/mechanical-engineering/thermodynamics/247-163-4.png">
Answer» D. <img src="/_files/images/mechanical-engineering/thermodynamics/247-163-4.png">

Discussion

2483.	In an isolated system, neither the heat and work nor the, mass of the working substance crosses the boundary of the system.
A.	True
B.	False
Answer» B. False

Discussion

2484.	The compression ratio is the ratio of
A.	swept volume to total volume
B.	total volume to swept volume
C.	swept volume to clearance volume
D.	total volume to clearance volume
Answer» E.

Discussion

2485.	The efficiency of Ericsson cycle is __________ Carnot cycle.
A.	greater than
B.	less than
C.	equal to
Answer» D.

Discussion

2486.	For the same compression ratio, the efficiency of Diesel cycle is __________ Otto cycle.
A.	greater than
B.	less than
C.	equal to
Answer» C. equal to

Discussion

2487.	Mond gas is obtained by
A.	partial combusion of coal, coke, anthracite coal or charcoal in a mixed air steam blast
B.	carbonisation of bituminous coal
C.	passing steam over incandescent coke
D.	passing air and a large amount of steam over waste coal at about 650 C
Answer» E.

Discussion

2488.	The natural solid fuel is
A.	wood
B.	coke
C.	anthracite coal
D.	pulverised coal
Answer» B. coke

Discussion

2489.	The condition for the reversibility of a cycle is
A.	the pressure and temperature of the working substance must not differ, appreciably, from those of the surroundings at any stage in the process
B.	all the processes, taking place in the cycle of operation, must be extremely slow
C.	the working parts of the engine must be friction free
D.	all of the above
Answer» E.

Discussion

2490.	The amount of heat given out by the complete combustion of 1 kg of fuel is known as calorific value of solid or liquid fuel.
A.	True
B.	False
Answer» B. False

Discussion

2491.	Carnot cycle consists of
A.	two constant volume and two isentropic processes
B.	two isothermal and two isentropic processes
C.	two constant pressure and two isentropic processes
D.	one constant volume, one constant pressure and two isentropic processes
Answer» C. two constant pressure and two isentropic processes

Discussion

2492.	Stirling cycle consists of
A.	two constant volume and two isentropic processes
B.	two constant volume and two isothermal processes
C.	two constant pressure and two isothermal processes
D.	one constant volume, one constant pressure and two isentropic processes
Answer» C. two constant pressure and two isothermal processes

Discussion

2493.	In open cycle gas turbine plants
A.	the indirect heat exchanger and cooler is avoided
B.	direct combustion system is used
C.	a condenser is used
D.	all of the above
Answer» E.

Discussion

2494.	The ratio of molar specific heats for monoatomic gas is
A.	1
B.	1.4
C.	1.67
D.	1.87
Answer» D. 1.87

Discussion

2495.	A triatomic molecule consists of __________ atoms.
A.	one
B.	two
C.	three
D.	four
Answer» D. four

Discussion

2496.	The main cause for the irreversibility is
A.	mechanical and fluid friction
B.	unrestricted expansion
C.	heat transfer with a finite temperature difference
D.	all of the above
Answer» E.

Discussion

2497.	The volumetric or molar specific heat at constant pressure is the product of
A.	molecular mass of the gas and the specific heat at constant volume
B.	atomic mass of the gas and the gas constant
C.	molecular mass of the gas and the gas constant
D.	none of the above
Answer» E.

Discussion

2498.	A cycle consisting of __________ and two isothermal processes is known as Stirling cycle.
A.	two constant pressure
B.	two constant volume
C.	two isentropic
D.	one constant pressure, one constant volume
Answer» C. two isentropic

Discussion

2499.	Which of the following is an intensive property of a thermodynamic system?
A.	Volume
B.	Temperature
C.	Mass
D.	Energy
Answer» C. Mass

Discussion

2500.	The heat and mechanical energies are mutually convertible. This statement was established by
A.	Boyle
B.	Charles
C.	Joule
D.	none of these
Answer» D. none of these

Discussion

Explore topic-wise MCQs in Engineering.

According to Regnault's law, the specific heat at constant pressure (cp) and specific heat at constant volume (cv) __________ with the change in pressure and temperature of the gas.

In an extensive property of a thermodynamic system

When a gas is heated at constant pressure

Wood charcoal is produced by heating the wood at 100 C.

Equal volumes of all gases, at the same temperature and pressure, contain equal number of molecules. This statement is called Avogadro's law.

The atomic mass of an element is the number of times the atom of that element is heavier than the hydrogen atom.

For the same maximum pressure and temperature,

In a steady flow process, the rate of

The entropy of the universe is continually on the increase.

Which of the following process can be made reversible with the help of a regenerator?

A cycle consisting of two isothermal and two isentropic processes, is known as

The unit of energy is S. I. units is

As per Charles' law, the volume of a given mass of a perfect gas varies __________ as its absolute temperature, when the absolute pressure remains constant.

Liquid fuels have lower efficiency than solid fuels.

Liquid fuels consist of hydrocarbons.

Ericsson cycle consists of two constant pressure and two isothermal processes.

One kg of carbon produces __________ kg of carbon dioxide.

The expansion ratio (r) is the ratio of (where v1 = Volume at the beginning of expansion, and v2 = Volume at the end of expansion)

The isothermal and isentropic processes are reversible non-flow processes.

The blast furnace gas is a by-product in the production of pig iron in the blast furnace.

Which is the incorrect statement about Carnot cycle?

When two bodies are in thermal equilibrium with a third body, they are also in thermal equilibrium with each other. This statement is called

The area under the temperature-entropy curve (T - s curve) of any thermodynamic process represents

The heating of a gas at constant pressure is governed by Charles' law.

The area under the temperature-entropy curve (i. e. T - s curve) of any thermodynamic process represents the workdone during the process.

A closed system is one in which heat and work crosses the boundary of the system but the mass of the working substance does not crosses the boundary of the system.

The dual combustion cycle consists of one constant pressure, two constant volume and two isentropic processes.

The specific heat at constant volume is

According to kinetic theory of gases, the velocity of molecules __________ with the increase in temperature.

The hard coke is obtained when carbonisation of coal is carried out at

According to First law of thermodynamics,

The root mean square velocity of the gas molecules is given by (where k = Boltzmann's constant, T = Absolute temperature, and m = Mass of one molecule of a gas)

In an isolated system, neither the heat and work nor the, mass of the working substance crosses the boundary of the system.

The compression ratio is the ratio of

The efficiency of Ericsson cycle is __________ Carnot cycle.

For the same compression ratio, the efficiency of Diesel cycle is __________ Otto cycle.

Mond gas is obtained by

The natural solid fuel is

The condition for the reversibility of a cycle is

The amount of heat given out by the complete combustion of 1 kg of fuel is known as calorific value of solid or liquid fuel.

Carnot cycle consists of

Stirling cycle consists of

In open cycle gas turbine plants

The ratio of molar specific heats for monoatomic gas is

A triatomic molecule consists of __________ atoms.

The main cause for the irreversibility is

The volumetric or molar specific heat at constant pressure is the product of

A cycle consisting of __________ and two isothermal processes is known as Stirling cycle.

Which of the following is an intensive property of a thermodynamic system?

The heat and mechanical energies are mutually convertible. This statement was established by