4791 + Mcqs in Mechanical Engineering McqOptions

1.	Kelvin-Planck's law deals with
A.	conservation of work
B.	conservation of heat
C.	conversion of heat into work
D.	conversion of work into heat
Answer» D. conversion of work into heat

Discussion

2.	Otto cycle efficiency is higher than Diesel cycle efficiency for the same compression ratio and heat input because in Otto cycle
A.	combustion is at constant volume
B.	expansion and compression are isentropic
C.	maximum temperature is higher
D.	heat rejection is lower
Answer» E.

Discussion

3.	A mixture of gas expands from 0.03 m3 to 0.06 m3 at a constant pressure of 1 MPa and absorbs 84 kJ of heat during the process. The change in internal energy of the mixture is
A.	30 kJ
B.	54 kJ
C.	84 kJ
D.	114 kJ
Answer» C. 84 kJ

Discussion

4.	The example of snag grinding is
A.	trimming the surface left by sprues and risers on castings
B.	grinding the parting line left on castings
C.	removing flash on forgings
D.	all of these
Answer» E.

Discussion

5.	The angle between the shear plane and __________ is called shear angle.
A.	work surface
B.	tool face
Answer» B. tool face

Discussion

6.	In determining the various forces on the chip, Merchant assumed that the
A.	cutting edge of the tool is sharp and it does not make any flank contact with the workpiece
B.	only continuous chip without built-up-edge is produced
C.	cutting velocity remains constant
D.	all of the above
Answer» E.

Discussion

7.	The type of reamer used for reaming soft aluminium or copper, is
A.	straight fluted reamer
B.	left hand spiral fluted reamer
C.	right hand spiral fluted reamer
D.	any one of these
Answer» C. right hand spiral fluted reamer

Discussion

8.	Up milling is also called conventional milling.
A.	Agree
B.	Disagree
Answer» B. Disagree

Discussion

9.	The tool material, for faster machining, should have
A.	wear resistance
B.	red hardness
C.	toughness
D.	all of these
Answer» E.

Discussion

10.	Dielectric is used in
A.	electro-chemical machining
B.	ultra-sonic machining
C.	electro-discharge machining
D.	laser machining
Answer» D. laser machining

Discussion

11.	Ceramic tools has greater tool life than carbide tools.
A.	True
B.	False
Answer» B. False

Discussion

12.	Fixtures are used
A.	for holding and guiding the tool in drilling, reaming or tapping operations
B.	for holding the work in milling, grinding, planing or turning operations
C.	to check the accuracy of workpiece
D.	none of the above
Answer» C. to check the accuracy of workpiece

Discussion

13.	According to Gay-Lussac law, the absolute pressure of a given mass of a perfect gas varies __________ as its absolute temperature, when the volume remains constant.
A.	directly
B.	indirectly
Answer» B. indirectly

Discussion

14.	A process, in which the temperature of the working substance remains constant during its expansion or compression, is called
A.	isothermal process
B.	hyperbolic process
C.	adiabatic process
D.	polytropic process
Answer» B. hyperbolic process

Discussion

15.	Which of the following gas has the highest calorific value?
A.	Coal gas
B.	Producer gas
C.	Mond gas
D.	Blast furnace gas
Answer» B. Producer gas

Discussion

16.	According to Avogadro's law
A.	the product of the gas constant and the molecular mass of an ideal gas is constant
B.	the sum of partial pressure of the mixture of two gases is sum of the two
C.	equal volumes of all gases, at the same temperature and pressure, contain equal number of molecules
D.	all of the above
Answer» D. all of the above

Discussion

17.	When the gas is cooled at constant pressure,
A.	its temperature increases but volume decreases
B.	its volume increases but temperature decreases
C.	both temperature and volume increases
D.	both temperature and volume decreases
Answer» E.

Discussion

18.	The oxygen atom is __________ times heavier than the hydrogen atom.
A.	2
B.	4
C.	8
D.	16
Answer» E.

Discussion

19.	The work ratio of a gas turbine plant is given by
A.	<img src="/_files/images/mechanical-engineering/thermodynamics/253-233-1.png">
B.	<img src="/_files/images/mechanical-engineering/thermodynamics/253-233-2.png">
C.	<img src="/_files/images/mechanical-engineering/thermodynamics/253-233-3.png">
D.	<img src="/_files/images/mechanical-engineering/thermodynamics/253-233-4.png">
Answer» B. <img src="/_files/images/mechanical-engineering/thermodynamics/253-233-2.png">

Discussion

20.	The loss of kinetic energy during elastic impact is zero.
A.	Agree
B.	Disagree
Answer» B. Disagree

Discussion

21.	The overturning of a vehicle on a level circular path can be avoided if the velocity of vehicle is __________ .
A.	less than
B.	greater than
Answer» B. greater than

Discussion

22.	Which of the following is a scalar quantity?
A.	Force
B.	Speed
C.	Velocity
D.	Acceleration
Answer» C. Velocity

Discussion

23.	The unit of energy in S.I. units is
A.	dyne
B.	watt
C.	kg-m
D.	joule
Answer» E.

Discussion

24.	The angle of inclination of the plane at which the body begins to move down the plane, is called
A.	angle of friction
B.	angle of repose
C.	angle of projection
D.	none of these
Answer» B. angle of repose

Discussion

25.	The Rankine's constant for a mild steel column with both ends hinged is
A.	1/750
B.	1/1600
C.	1/7500
D.	1/9000
Answer» D. 1/9000

Discussion

26.	Three forces acting on a rigid body are represented in magnitude, direction and line of action by the three sides of a triangle taken in order. The forces are equivalent to a couple whose moment is equal to
A.	area of the triangle
B.	twice the area of the triangle
C.	half the area of the triangle
D.	none of these
Answer» C. half the area of the triangle

Discussion

27.	The operation of smoothing and squaring the surface around a hole is known as
A.	counter-sinking
B.	counter-boring
C.	trepanning
D.	spot facing
Answer» E.

Discussion

28.	The cutting speed of a drill depends upon the
A.	material of drill
B.	type of material to be drilled
C.	quality of surface finish desired
D.	all of these
Answer» E.

Discussion

29.	A grinding wheel is said to be of __________ if it holds the abrasive grains more securely.
A.	soft grade
B.	medium grade
C.	hard grade
Answer» D.

Discussion

30.	In ultra-sonic machining, tool is made of
A.	tungsten carbide
B.	brass or copper
C.	diamond
D.	stainless steel
Answer» C. diamond

Discussion

31.	Crater wear is mainly due to the phenomenon known as
A.	adhesion of metals
B.	oxidation of metals
C.	diffusion of metals
D.	all of these
Answer» D. all of these

Discussion

32.	The width of cutting edge of a parting-off tool varies from
A.	3 to 12 mm
B.	5 to 20 mm
C.	8 to 30 mm
D.	15 to 40 mm
Answer» B. 5 to 20 mm

Discussion

33.	The lip clearance angle should decrease towards the centre of the drill than at the circumference.
A.	Yes
B.	No
Answer» C.

Discussion

34.	The abrasive recommended for grinding materials of low tensile strength is
A.	silicon carbide
B.	aluminium oxide
C.	sand stone
D.	diamond
Answer» B. aluminium oxide

Discussion

35.	Hard and tough materials like cast iron should be turned at
A.	slow speed
B.	high speed
C.	any speed
D.	certain specific speed
Answer» B. high speed

Discussion

36.	In a shaper
A.	tool is stationary and work reciprocates
B.	work is stationary and tool reciprocates
C.	tool moves over stationary work
D.	tool moves over reciprocating work
Answer» C. tool moves over stationary work

Discussion

37.	In drilling brass, a drill with
A.	zero helix angle is used
B.	low helix angle is used
C.	high helix angle is used
D.	any helix angle can be used
Answer» C. high helix angle is used

Discussion

38.	When the shear angle is large
A.	path of shear is short and chip is thin
B.	path of shear is large and chip is thick
C.	path of shear is short and chip is thick
D.	path of shear is large and chip is thin
Answer» B. path of shear is large and chip is thick

Discussion

39.	The cutting speed for counter-boring should be __________ that of drilling operation.
A.	equal to
B.	less than
C.	greater than
Answer» D.

Discussion

40.	The amount of heat required to raise the temperature of unit mass of a gas through one degree at constant pressure is called specific heat at constant pressure.
A.	True
B.	False
Answer» B. False

Discussion

41.	When a fluid is allowed to expand suddenly into a vaccum chamber through an orifice of large dimensions, the process is known as free expansion process.
A.	True
B.	False
Answer» B. False

Discussion

42.	One molecule of oxygen consists of __________ atoms of oxygen.
A.	2
B.	4
C.	8
D.	16
Answer» B. 4

Discussion

43.	One kg of carbon monoxide requires 4/7 kg of oxygen and produces
A.	11/3 kg of carbon dioxide gas
B.	7/3 kg of carbon monoxide gas
C.	11/7 kg of carbon dioxide gas
D.	8/3 kg of carbon monoxide gas
Answer» D. 8/3 kg of carbon monoxide gas

Discussion

44.	When a gas is heated at constant volume
A.	its temperature will increase
B.	its pressure will increase
C.	both temperature and pressure will increase
D.	neither temperature nor pressure will increase
Answer» D. neither temperature nor pressure will increase

Discussion

45.	The entropy may be expressed as a function of
A.	pressure and temperature
B.	temperature and volume
C.	heat and work
D.	all of these
Answer» B. temperature and volume

Discussion

46.	The polytropic index (n) is given by
A.	<img src="/_files/images/mechanical-engineering/thermodynamics/244-126-1.png">
B.	<img src="/_files/images/mechanical-engineering/thermodynamics/244-126-2.png">
C.	<img src="/_files/images/mechanical-engineering/thermodynamics/244-126-3.png">
D.	<img src="/_files/images/mechanical-engineering/thermodynamics/244-126-4.png">
Answer» C. <img src="/_files/images/mechanical-engineering/thermodynamics/244-126-3.png">

Discussion

47.	The bomb calorimeter is used for finding the __________ calorific value of solid and liquid fuels.
A.	higher
B.	lower
Answer» B. lower

Discussion

48.	The mass of carbon per kg of flue gas is given by
A.	<img src="/_files/images/mechanical-engineering/thermodynamics/260-318-1.png">
B.	<img src="/_files/images/mechanical-engineering/thermodynamics/260-318-2.png">
C.	<img src="/_files/images/mechanical-engineering/thermodynamics/260-318-3.png">
D.	<img src="/_files/images/mechanical-engineering/thermodynamics/260-318-4.png">
Answer» B. <img src="/_files/images/mechanical-engineering/thermodynamics/260-318-2.png">

Discussion

49.	When the gas is heated at constant pressure, the heat supplied
A.	increases the internal energy of the gas
B.	increases the temperature of the gas
C.	does some external work during expansion
D.	Both (B) and (C)
Answer» E.

Discussion

50.	A cycle consisting of two constant pressure and two isothermal processes is known as Ericsson cycle.
A.	True
B.	False
Answer» B. False

Discussion

Explore topic-wise MCQs in Testing Subject.

Kelvin-Planck's law deals with

Otto cycle efficiency is higher than Diesel cycle efficiency for the same compression ratio and heat input because in Otto cycle

A mixture of gas expands from 0.03 m3 to 0.06 m3 at a constant pressure of 1 MPa and absorbs 84 kJ of heat during the process. The change in internal energy of the mixture is

The example of snag grinding is

The angle between the shear plane and __________ is called shear angle.

In determining the various forces on the chip, Merchant assumed that the

The type of reamer used for reaming soft aluminium or copper, is

Up milling is also called conventional milling.

The tool material, for faster machining, should have

Dielectric is used in

Ceramic tools has greater tool life than carbide tools.

Fixtures are used

According to Gay-Lussac law, the absolute pressure of a given mass of a perfect gas varies __________ as its absolute temperature, when the volume remains constant.

A process, in which the temperature of the working substance remains constant during its expansion or compression, is called

Which of the following gas has the highest calorific value?

According to Avogadro's law

When the gas is cooled at constant pressure,

The oxygen atom is __________ times heavier than the hydrogen atom.

The work ratio of a gas turbine plant is given by

The loss of kinetic energy during elastic impact is zero.

The overturning of a vehicle on a level circular path can be avoided if the velocity of vehicle is __________ .

Which of the following is a scalar quantity?

The unit of energy in S.I. units is

The angle of inclination of the plane at which the body begins to move down the plane, is called

The Rankine's constant for a mild steel column with both ends hinged is

Three forces acting on a rigid body are represented in magnitude, direction and line of action by the three sides of a triangle taken in order. The forces are equivalent to a couple whose moment is equal to

The operation of smoothing and squaring the surface around a hole is known as

The cutting speed of a drill depends upon the

A grinding wheel is said to be of __________ if it holds the abrasive grains more securely.

In ultra-sonic machining, tool is made of

Crater wear is mainly due to the phenomenon known as

The width of cutting edge of a parting-off tool varies from

The lip clearance angle should decrease towards the centre of the drill than at the circumference.

The abrasive recommended for grinding materials of low tensile strength is

Hard and tough materials like cast iron should be turned at

In a shaper

In drilling brass, a drill with

When the shear angle is large

The cutting speed for counter-boring should be __________ that of drilling operation.

The amount of heat required to raise the temperature of unit mass of a gas through one degree at constant pressure is called specific heat at constant pressure.

When a fluid is allowed to expand suddenly into a vaccum chamber through an orifice of large dimensions, the process is known as free expansion process.

One molecule of oxygen consists of __________ atoms of oxygen.

One kg of carbon monoxide requires 4/7 kg of oxygen and produces

When a gas is heated at constant volume

The entropy may be expressed as a function of

The polytropic index (n) is given by

The bomb calorimeter is used for finding the __________ calorific value of solid and liquid fuels.

The mass of carbon per kg of flue gas is given by

When the gas is heated at constant pressure, the heat supplied

A cycle consisting of two constant pressure and two isothermal processes is known as Ericsson cycle.