Explore topic-wise MCQs in Mechanical Engineering.

This section includes 905 Mcqs, each offering curated multiple-choice questions to sharpen your Mechanical Engineering knowledge and support exam preparation. Choose a topic below to get started.

51.

The pressure of air __________ with the increase of height from the surface of the earth.

A. oes not change
B. ecreases
C. ncreases
D. one of these
Answer» C. ncreases
52.

The point at which the resultant pressure on an immersed surface acts, is known as

A. entre of gravity
B. entre of depth
C. entre of pressure
D. entre of immersed surface
Answer» D. entre of immersed surface
53.

The efficiency of jet propulsion for a ship with inlet orifices at right angles to the direction of motion of ship is given by

A. 2(Vr - v) v]/ Vr²
B. 2(Vr + v) v]/ Vr²
C. (Vr - v) v]/ Vr
D. (Vr + v) v]/ Vr
Answer» B. 2(Vr + v) v]/ Vr²
54.

If a pump is handling water and is discharging a certain flow Q at a constant total dynamic head requiring a definite B.H.P., the same pump when handling a liquid of specific gravity 0.75 and viscosity nearly same as of water , the horse power required will be

A. ame
B. .75 B.H.P
C. .H.P./0.75
D. .5 B.H.P
Answer» C. .H.P./0.75
55.

The total pressure force on a plane area is equal to the area multiplied by the intensity of pressure at the Centroid, if

A. he area is horizontal
B. he area is vertical
C. he area is inclined
D. ll of the above
Answer» E.
56.

A glass tube of small diameter (d) is dipped in fluid. The height of rise or fall in the tube given by (where w = Specific weight of liquid, α = Angle of contact of the liquid surface, and σ = Surface tension)

A. wd/σ cosα
B. cosα/4wd
C. σ cosα/wd
D. d/4σ cosα
Answer» D. d/4σ cosα
57.

The viscosity of water at 20°C is

A. ne stoke
B. ne centistoke
C. ne poise
D. ne centipoise
Answer» E.
58.

The intensity of pressure at any point, in a liquid, is

A. irectly proportional to the area of the vessel containing liquid
B. irectly proportional to the depth of liquid from the surface
C. irectly proportional to the length of the vessel containing liquid
D. nversely proportional to the depth of liquid from the surface
Answer» C. irectly proportional to the length of the vessel containing liquid
59.

The total pressure on the top of a closed cylindrical vessel completely filled up with a liquid is

A. irectly proportional to (radius)2
B. nversely proportional to (radius)2
C. irectly proportional to (radius)4
D. nversely proportional to (radius)4
Answer» D. nversely proportional to (radius)4
60.

The pressure in Pascal’s at a depth of 1 m below the free surface of a body of water will be equal to

A. Pa
B. 1 Pa
C. 81 Pa
D. 810 Pa
Answer» E.
61.

When the water level on the downstream side of a weir is above the top surface of a weir, the weir is known as

A. arrow-crested weir
B. road-crested weir
C. gee weir
D. ubmerged weir
Answer» E.
62.

If a body floating in a liquid occupies a new position and remains at rest in this new position, when given a small angular displacement, the body is said to be in __________ equilibrium.

A. eutral
B. table
C. nstable
D. one of these
Answer» B. table
63.

A flow through a long pipe at decreasing rate is called __________ uniform flow.

A. teady
B. nsteady
C. oth A and B
D. one of these
Answer» C. oth A and B
64.

The surface tension of mercury at normal temperature is __________ that of water.

A. ame as
B. ower than
C. igher than
D. one of these
Answer» D. one of these
65.

The highest efficiency is obtained with a channel of __________ section.

A. ircular
B. quare
C. ectangular
D. rapezoidal
Answer» E.
66.

When the Venturimeter is inclined, then for a given flow it will show __________ reading.

A. ame
B. ore
C. ess
D. one of these
Answer» B. ore
67.

A notch is used to measure __________ of liquids.

A. ressure
B. ischarge
C. elocity
D. olume
Answer» C. elocity
68.

A bucket of water is hanging from a spring balance. An iron piece is suspended into water without touching sides of bucket from another support. The spring balance reading will

A. ncrease
B. ecrease
C. emain same
D. ncrease/decrease depending on depth of immersion
Answer» D. ncrease/decrease depending on depth of immersion
69.

The pressure of liquid at throat in a Venturimeter is __________ than that at inlet.

A. igher
B. ower
C. ame
D. one of these
Answer» C. ame
70.

The length AB of a pipe ABC in which the liquid is flowing has diameter (d1) and is suddenly contracted to diameter (d2) at B which is constant for the length BC. The loss of head due to sudden contraction, assuming coefficient of contraction as 0.62, is

A. ₁²/2g
B. ₂²/2g
C. .5 v₁²/2g
D. .375 v₂²/2g
Answer» E.
71.

When the coefficient of discharge (Cd) is 0.623, then the general equation for discharge over a rectangular weir is

A. .84(L - 0.1nH)H3/2
B. .84(L - nH)H2
C. .84(L - 0.1nH)H5/2
D. .84(L - nH)H3
Answer» B. .84(L - nH)H2
72.

A channel is said to be of most economical cross-section, if

A. t gives maximum discharge for a given cross-sectional area and bed slope
B. t has minimum wetted perimeter
C. t involves lesser excavation for the designed amount of discharge
D. ll of the above
Answer» E.
73.

The discharge in an open channel corresponding to critical depth is

A. ero
B. inimum
C. aximum
D. one of these
Answer» D. one of these
74.

Coefficient of velocity is defined as the ratio of

A. ctual velocity of jet at vena contracta to the theoretical velocity
B. rea of jet at vena contracta to the area of orifice
C. ctual discharge through an orifice to the theoretical discharge
D. one of the above
Answer» B. rea of jet at vena contracta to the area of orifice
75.

A flow in which the volume of a fluid and its density does not change during the flow is called _________ flow.

A. ncompressible
B. ompressible
C. iscous
D. one of these
Answer» B. ompressible
76.

If Hg is the gross or total head and hf is the head lost due to friction, then net or effective head (H) is given by

A. = Hg/hf
B. = Hg × hf
C. = Hg + hf
D. = Hg - hf
Answer» E.
77.

Which of the following meters is not associated with viscosity?

A. ed wood
B. ay bolt
C. ngler
D. rsat
Answer» E.
78.

A flow in which __________ force is dominating over the viscosity is called turbulent flow.

A. lastic
B. urface tension
C. iscous
D. nertia
Answer» E.
79.

An orifice is said to be large, if

A. he size of orifice is large
B. he velocity of flow is large
C. he available head of liquid is more than 5 times the height of orifice
D. he available head of liquid is less than 5 times the height of orifice
Answer» E.
80.

A Pelton wheel develops 1750 kW under a head of 100 meters while running at 200 r.p.m. and discharging 2500 liters of water per second. The unit speed of the wheel is

A. 0 r.p.m.
B. 0 r.p.m.
C. 0 r.p.m.
D. 0 r.p.m.
Answer» C. 0 r.p.m.
81.

A flow whose streamline is represented by a straight line, is called __________ dimensional flow.

A. ne
B. wo
C. hree
D. our
Answer» B. wo
82.

According to Darcy's formula, the loss of head due to friction in the pipe is (where f = Darcy's coefficient, l = Length of pipe, v = Velocity of liquid in pipe, and d = Diameter of pipe)

A. lv²/2gd
B. lv²/gd
C. flv²/2gd
D. flv²/2gd
Answer» E.
83.

The maximum hydraulic efficiency of an impulse turbine is (where φ = Angle of blade tip at outlet)

A. 1 + cos φ)/2
B. 1 - cos φ)/2
C. 1 + sin φ)/2
D. 1 - sin φ)/2
Answer» B. 1 - cos φ)/2
84.

Bulk modulus of a fluid is the ratio of

A. hear stress to shear strain
B. ncrease in volume to the viscosity of fluid
C. ncrease in pressure to the volumetric strain
D. ritical velocity to the viscosity of fluid
Answer» D. ritical velocity to the viscosity of fluid
85.

The ratio of the inertia force to the __________ is called Euler's number.

A. ressure force
B. lastic force
C. urface tension force
D. iscous force
Answer» B. lastic force
86.

A hemispherical tank of radius (R) has an orifice of cross-sectional area (a) at its bottom and is full of liquid. The time required to empty the tank completely is

A. 4π R1/2/15Cd × a √(2g)
B. 4π R3/2/15Cd × a √(2g)
C. 4π R5/2/15Cd × a √(2g)
D. 4π R7/2/15Cd × a √(2g)
Answer» D. 4π R7/2/15Cd × a √(2g)
87.

The specific speed of a centrifugal pump, delivering 750 liters of water per second against a head of 15 meters at 725 r.p.m., is

A. 4.8 r.p.m.
B. 8.2 r.p.m
C. 2.4 r.p.m.
D. 48 r.p.m
Answer» D. 48 r.p.m
88.

At the center line of a pipe flowing under pressure where the velocity gradient is zero, the shear stress will be

A. inimum
B. aximum
C. ero
D. ould be any value
Answer» E.
89.

A moving fluid mass may be brought to a static equilibrium position, by applying an imaginary inertia force of the same magnitude as that of the accelerating force but in the opposite direction. This statement is called

A. ascal’s law
B. rchimedes’s principle
C. -Alembert’s principle
D. one of these
Answer» D. one of these
90.

The force exerted by a moving fluid on an immersed body is directly proportional to the rate of change of momentum due to the presence of the body. This statement is called

A. ewton's law of motion
B. ewton's law of cooling
C. ewton's law of viscosity
D. ewton's law of resistance
Answer» E.
91.

For a perfect incompressible liquid, flowing in a continuous stream, the total energy of a particle remains the same, while the particle moves from one point to another. This statement is called

A. ontinuity equation
B. ernoulli’s equation
C. ascal’s law
D. rchimedes’s principle
Answer» C. ascal’s law
92.

When a body is immersed wholly or partially in a liquid, it is lifted up by a force equal to the weight of liquid displaced by the body. This statement is called

A. ascal’s law
B. rchimedes’s principle
C. rinciple of flotation
D. ernoulli’s theorem
Answer» C. rinciple of flotation
93.

The rise of liquid along the walls of a revolving cylinder about the initial level is _________ the depression of the liquid at the axis of rotation.

A. ame as
B. ess than
C. ore than
D. one of these
Answer» B. ess than
94.

Newton's law of viscosity is a relationship between

A. ressure, velocity and temperature
B. hear stress and rate of shear strain
C. hear stress and velocity
D. ate of shear strain and temperature
Answer» C. hear stress and velocity
95.

A compound pipe is required to be replaced by a new pipe. The two pipes are said to be equivalent, if

A. ength of both the pipes is same
B. iameter of both the pipes is same
C. oss of head and discharge of both the pipes is same
D. oss of head and velocity of flow in both the pipes is same
Answer» D. oss of head and velocity of flow in both the pipes is same
96.

The velocity through a channel of circular section will be maximum when the depth of water is __________ the diameter of the circular channel.

A. .34 times
B. .67 times
C. .81 times
D. .95 times
Answer» D. .95 times
97.

The Francis formula for the discharge over Cipoletti weir is

A. .84 LH1/2
B. .84 LH
C. .84 LH3/2
D. .84 LH5/2
Answer» D. .84 LH5/2
98.

The gross or total head of the turbine is the ___________ of the water levels at the head race and tail race.

A. um
B. ifference
C. roduct
D. one of these
Answer» C. roduct
99.

The most economical section of a rectangular channel is one which has hydraulic mean depth or hydraulic radius equal to

A. alf the depth
B. alf the breadth
C. wice the depth
D. wice the breadth
Answer» B. alf the breadth
100.

The ratio of the inertia force to the elastic force is called

A. eynold's number
B. roude's number
C. eber's number
D. ach number
Answer» E.