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.

1.

The tangential velocity of the water element having a free vortex is

A. irectly proportional to its distance from the centre
B. nversely proportional to its distance from the centre
C. irectly proportional to its (distance)2 from the centre
D. nversely proportional to its (distance)2 from the centre
Answer» C. irectly proportional to its (distance)2 from the centre
2.

A large Reynold number is indication of

A. mooth and streamline flow
B. aminar flow
C. teady flow
D. ighly turbulent flow
Answer» E.
3.

Motion of a liquid in a volute casing of a centrifugal pump is an example of

A. otational flow
B. adial
C. orced spiral vortex flow
D. piral vortex flow
Answer» E.
4.

The product of mass and acceleration of flowing liquid is called

A. nertia force
B. iscous force
C. ravity force
D. ressure force
Answer» B. iscous force
5.

When a body is placed over a liquid, it will float if

A. ravitational force is equal to the up-thrust of the liquid
B. ravitational force is less than the up-thrust of the liquid
C. ravitational force is more than the up-thrust of the liquid
D. one of the above
Answer» C. ravitational force is more than the up-thrust of the liquid
6.

Which of the following instrument can be used for measuring speed of an aeroplane?

A. enturimeter
B. rifice plate
C. itot tube
D. otameter
Answer» D. otameter
7.

The discharge of a depressed nappe is 6 to 7 percent __________ that of a free nappe.

A. ess than
B. ore than
C. qual to
D. one of these
Answer» C. qual to
8.

The flow in a pipe or channel is said to be non-uniform when

A. he liquid particles at all sections have the same velocities
B. he liquid particles at different sections have different velocities
C. he quantity of liquid flowing per second is constant
D. ach liquid particle has a definite path
Answer» C. he quantity of liquid flowing per second is constant
9.

The torque required to overcome viscous resistance of a footstep bearing is (where μ = Viscosity of the oil, N = Speed of the shaft, R = Radius of the shaft, and t = Thickness of the oil film)

A. π²NR/60t
B. π²NR²/60t
C. π²NR³/60t
D. π²NR⁴/60t
Answer» E.
10.

When a liquid is flowing through a pipe, the velocity of the liquid is

A. aximum at the centre and minimum near the walls
B. inimum at the centre and maximum near the walls
C. ero at the centre and maximum near the walls
D. aximum at the centre and zero near the walls
Answer» B. inimum at the centre and maximum near the walls
11.

According to Newton's law of viscosity, the shear stress on a layer of a fluid is __________ to the rate of shear strain.

A. qual to
B. irectly proportional
C. nversely proportional
D. one of these
Answer» C. nversely proportional
12.

The region between the separation streamline and the boundary surface of the solid body is known as

A. ake
B. rag
C. ift
D. oundary layer
Answer» B. rag
13.

If the ratios of all the corresponding linear dimensions are equal, then the model and the prototype are said to have

A. eometric similarity
B. inematic similarity
C. ynamic similarity
D. one of these
Answer» B. inematic similarity
14.

A flow whose streamline is represented by a curve, is called

A. ne-dimensional flow
B. wo-dimensional flow
C. hree-dimensional flow
D. our-dimensional flow
Answer» C. hree-dimensional flow
15.

The discharge of a double acting reciprocating pump is (where L = Length of stroke, A = Cross-sectional area of piston, and N = Speed of crank in r.p.m.)

A. .A.N
B. L.A.N
C. L.A.N)/60
D. 2 L.A.N)/60
Answer» E.
16.

A flow in which each liquid particle has a definite path, and the paths of individual particles do not cross each other, is called

A. teady flow
B. niform flow
C. treamline flow
D. urbulent flow
Answer» D. urbulent flow
17.

The speed of sound in a ideal gas varies directly as it’s

A. bsolute temperature
B. emperature
C. ensity
D. odulus of elasticity
Answer» B. emperature
18.

The depth of the bucket for a Pelton wheel is generally _________ the diameter of jet.

A. qual to
B. .2 times
C. .8 times
D. ouble
Answer» C. .8 times
19.

The width of the bucket for a Pelton wheel is generally ________ the diameter of jet.

A. ouble
B. hree times
C. our times
D. ive times
Answer» E.
20.

A metal with specific gravity of 'a' floating in a fluid of same specific gravity 'a' will

A. ink to bottom
B. loat over fluid
C. artly immersed
D. e fully immersed with top surface at fluid surface
Answer» E.
21.

Impulse turbine is generally fitted

A. t the level of tail race
B. ittle above the tail race
C. lightly below the tail race
D. bout 2.5 m above the tail race to avoid cavitations
Answer» C. lightly below the tail race
22.

According to Bernoulli's equation for steady ideal fluid flow

A. rinciple of conservation of mass holds
B. elocity and pressure are inversely proportional
C. otal energy is constant throughout
D. he energy is constant along a streamline but may vary across streamlines
Answer» E.
23.

Froude's number is the ratio of inertia force to

A. ressure force
B. lastic force
C. ravity force
D. urface tension force
Answer» D. urface tension force
24.

The hydraulic efficiency of an impulse turbine is maximum when velocity of wheel is _______ of the jet velocity,

A. ne-fourth
B. ne-half
C. hree-fourth
D. ouble
Answer» C. hree-fourth
25.

The kinematic viscosity of an oil (in stokes) whose specific gravity is 0.95 and viscosity 0.011 poise, is

A. .0116 stoke
B. .116 stoke
C. .0611 stoke
D. .611 stoke
Answer» B. .116 stoke
26.

When a body is placed over a liquid, it will sink down if

A. ravitational force is equal to the up-thrust of the liquid
B. ravitational force is less than the up-thrust of the liquid
C. ravitational force is more than the up-thrust of the liquid
D. one of the above
Answer» D. one of the above
27.

The pressure at a point in a fluid will not be same in all the directions when the fluid is

A. oving
B. iscous
C. iscous and static
D. iscous and moving
Answer» E.
28.

The force exerted by a jet of water (in a direction normal to flow) impinging on a fixed plate inclined at an angle θ with the jet is

A. waV/2g) × sin θ
B. waV/g) × sin θ
C. waV²/2g) × sin 2θ
D. waV²/g) × sin θ
Answer» D. waV²/g) × sin θ
29.

Theoretical power required (in watts) to drive a reciprocating pump is (where w = Specific weight of liquid to be pumped in N/m3, Q = Discharge of the pump in m3/s, Hs = Suction head in meters, and Hd = Delivery head in meters)

A. QHs
B. QHd
C. Q (Hs - Hd)
D. Q (Hs + Hd)
Answer» E.
30.

The pressure of fluid due to hammer blow is

A. irectly proportional to density of fluid
B. nversely proportional to density of fluid
C. irectly proportional to (density)1/2 of fluid
D. nversely proportional to (density)1/2 of fluid
Answer» D. nversely proportional to (density)1/2 of fluid
31.

An open tank containing liquid is moving with an acceleration on an inclined plane. The inclination of the free surface of the liquid will be __________ to the acceleration of the tank.

A. qual to
B. irectly proportional
C. nversely proportional
D. one of these
Answer» C. nversely proportional
32.

The efficiency of power transmission through pipe is (where H = Total supply head, and hf = Head lost due to friction in the pipe)

A. H - hf )/H
B. /(H - hf )
C. H + hf )/H
D. /(H + hf )
Answer» B. /(H - hf )
33.

In order to increase sensitivity of U-tube manometer, one leg is usually inclined by angle 'θ'. Sensitivity of inclined tube to sensitivity of U-tube is equal to

A. inθ
B. /Sinθ
C. os θ
D. /Cosθ
Answer» C. os θ
34.

Centrifugal pump is started with its delivery valve

A. ept fully closed
B. ept fully open
C. rrespective of any position
D. ept 50% open
Answer» B. ept fully open
35.

Axial flow pump is started with its delivery valve

A. ept fully closed
B. ept fully open
C. rrespective of any position
D. ept 50% open
Answer» C. rrespective of any position
36.

A fluid whose viscosity does not change with the rate of deformation or shear strain is known as

A. eal fluid
B. deal fluid
C. ewtonian fluid
D. on-Newtonian fluid
Answer» D. on-Newtonian fluid
37.

The force exerted (in Newton) by a jet of water impinging normally on a fixed plate is (where w = Specific weight of water in N/m3, a = Cross-sectional area of jet in m², and V = Velocity of jet in m/s)

A. aV / 2g
B. aV / g
C. aV² / 2g
D. aV² / g
Answer» E.
38.

According to fan laws, at constant pressure, the speed capacity and power vary

A. irectly as the air or gas density
B. nversely as square root of density
C. nversely as density
D. s square of density
Answer» C. nversely as density
39.

The shear stress between the two liquid layers is __________ proportional to the distance between two layers.

A. irectly
B. nversely
C. oth A and B
D. one of these
Answer» C. oth A and B
40.

Low specific speed of a pump implies it is

A. entrifugal pump
B. ixed flow pump
C. xial flow pump
D. one of the above
Answer» B. ixed flow pump
41.

One liter of water occupies a volume of

A. 00 cm3
B. 50 cm3
C. 00 cm3
D. 000 cm3
Answer» E.
42.

A flow is called super-sonic if the

A. elocity of flow is very high
B. ischarge is difficult to measure
C. ach number is between 1 and 6
D. one of these
Answer» D. one of these
43.

The specific weight of water in S.I. units is taken as

A. .81 kN/m3
B. .81 × 103 N/m3
C. .81 × 10-6 N/mm3
D. ny one of these
Answer» E.
44.

The total pressure on the top of a closed cylindrical vessel of radius (r) completely filled up with liquid of specific weight (w) and rotating at (ω) rad/s about its vertical axis, is

A. w ω² r²/4g
B. w ω² r³/4g
C. w ω² r⁴/4g
D. w ω² r²/2g
Answer» B. w ω² r³/4g
45.

The loss of head due to friction in a pipe of uniform diameter in which a viscous flow is taking place, is (where RN = Reynold number)

A. /RN
B. /RN
C. 6/RN
D. 4/RN
Answer» D. 4/RN
46.

The diameter of the nozzle (d) for maximum transmission of power is given by (where D = Diameter of pipe, f = Darcy’s coefficient of friction for pipe, and l = Length of pipe)

A. = (D⁵/8fl)1/2
B. = (D⁵/8fl)1/3
C. = (D⁵/8fl)1/4
D. = (D⁵/8fl)1/5
Answer» D. = (D⁵/8fl)1/5
47.

Water is a __________ fluid.

A. eal
B. deal
C. ewtonian
D. on-Newtonian
Answer» D. on-Newtonian
48.

The optimum value of vane exit angle for a centrifugal pump impeller is

A. 0-15°
B. 0-25°
C. 0-40°
D. 0-60°
Answer» C. 0-40°
49.

A flow in which the viscosity of fluid is dominating over the inertia force is called

A. teady flow
B. nsteady flow
C. aminar flow
D. urbulent flow
Answer» D. urbulent flow
50.

When a tank containing liquid moves with an acceleration in the horizontal direction, then the free surface of the liquid

A. emains horizontal
B. ecomes curved
C. alls on the front end
D. alls on the back end
Answer» D. alls on the back end