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.

101.

The total energy of each particle at various places in the case of perfect incompressible fluid flowing in continuous stream

A. eeps on increasing
B. eeps on decreasing
C. emain constant
D. ay increase/decrease
Answer» D. ay increase/decrease
102.

A liquid compressed in cylinder has a volume of 0.04 m3 at 50 kg/cm² and a volume of 0.039 m3 at 150 kg/cm². The bulk modulus of elasticity of liquid is

A. 00 kg/cm²
B. 000 kg/cm²
C. 0 × 10⁵ kg/cm²
D. 0 × 10⁶ kg/cm²
Answer» C. 0 × 10⁵ kg/cm²
103.

The discharge over a rectangular weir, considering the velocity of approach, is (whereH1 = H + Ha = Total height of water above the weir, H = Height of water over the crest of the weir, and Ha = Height of water due to velocity of approach)

A. 2/3) Cd × L.√2g [H1 - Ha]
B. 2/3) Cd × L. √2g [H13/2 - Ha3/2]
C. 2/3) Cd × L.√2g [H12 - Ha2]
D. 2/3) Cd × L. √2g [H15/2 - Ha5/2]
Answer» C. 2/3) Cd × L.√2g [H12 - Ha2]
104.

A vertical wall is subjected to a pressure due to one kind of liquid, on one of its sides. Which of the following statement is correct?

A. he pressure on the wall at the liquid level is minimum
B. he pressure on the bottom of the wall is maximum
C. he pressure on the wall at the liquid level is zero, and on the bottom of the wall is maximum
D. he pressure on the bottom of the wall is zero
Answer» D. he pressure on the bottom of the wall is zero
105.

The process of diffusion of one liquid into the other through a semi permeable membrane is called

A. iscosity
B. smosis
C. urface tension
D. ohesion
Answer» C. urface tension
106.

The loss of head due to viscosity for laminar flow in pipes is (where d = Diameter of pipe, l = Length of pipe, v = Velocity of the liquid in the pipe, μ = Viscosity of the liquid, and w = Specific weight of the flowing liquid)

A. μvl/wd²
B. μvl/wd²
C. 6μvl/wd²
D. 2μvl/wd²
Answer» E.
107.

The atmospheric pressure at sea level is

A. 03 kN/m2
B. 0.3 m of water
C. 60 mm of mercury
D. ll of these
Answer» E.
108.

The Euler's equation for the motion of liquids is based upon the assumption that

A. he fluid is non - viscous, homogeneous and incompressible
B. he velocity of flow is uniform over the section
C. he flow is continuous, steady and along the stream line
D. ll of the above
Answer» E.
109.

The length AB of a pipe ABC in which the liquid is flowing has diameter (d1) and is suddenly enlarged to diameter (d2) at B which is constant for the length BC. The loss of head due to sudden enlargement is

A. v₁ - v₂)²/g
B. v₁² - v₂²)/g
C. v₁ - v₂)²/2g
D. v₁² - v₂²)/2g
Answer» D. v₁² - v₂²)/2g
110.

The depth of center of pressure of an immersed surface, inclined at an angle 'θ' with the liquid surface lies at a distance equal to __________ the center of gravity.

A. G sin²θ/Ax̅ below
B. G sin²θ/Ax̅ above
C. G sinθ/Ax̅ below
D. G sinθ/Ax̅ above
Answer» B. G sin²θ/Ax̅ above
111.

The discharge through a large rectangular orifice is given by (where H1 = Height of the liquid above the top of the orifice, H2 = Height of the liquid above the bottom of the orifice, b = Breadth of the orifice, and Cd = Coefficient of discharge)

A. = (2/3) Cd × b × √(2g) × (H2 - H1)
B. = (2/3) Cd × b × √(2g) × (H21/2 - H11/2)
C. = (2/3) Cd × b × √(2g) × (H23/2 - H13/2)
D. = (2/3) Cd × b × √(2g) × (H22 - H12)
Answer» D. = (2/3) Cd × b × √(2g) × (H22 - H12)
112.

The length of a liquid stream while flowing over a weir __________ at the ends of the sill.

A. xpands
B. oes not change
C. ontracts
D. one of these
Answer» D. one of these
113.

According to Francis formula, the discharge over a rectangular weir is (where n = Number of end contractions)

A. 2/3) × Cd (L - nH) × √(2gh)
B. 2/3) × Cd (L - 0.1nH) × √(2g) × H3/2
C. 2/3) × Cd (L - nH) × √(2g) × H²
D. 2/3) × Cd (L - nH) × √(2g) × H5/2
Answer» C. 2/3) × Cd (L - nH) × √(2g) × H²
114.

Power required (in watts) to drive a centrifugal pump is (where Hm = Manometric head in metres, w = Specific weight in N/m3, Q = Discharge of the pump in m3/s, and ηo = Overall efficiency of the pump)

A. w Hm) / (Q × ηo)
B. w Hm Q) / ηo
C. w Q) / (Hm × ηo)
D. w Qηo) / Hm
Answer» C. w Q) / (Hm × ηo)
115.

According to Bazin's formula, the discharge over a rectangular weir is mL2g x H3/2 where m is equal to

A. .405 + (0.003/H)
B. .003 + (0.405/H)
C. .405 + (H/0.003)
D. .003 + (H/0.405)
Answer» B. .003 + (0.405/H)
116.

The ratio of specific weight of a liquid to the specific weight of pure water at a standard temperature is called

A. ensity of liquid
B. pecific gravity of liquid
C. ompressibility of liquid
D. urface tension of liquid
Answer» C. ompressibility of liquid
117.

The centre of pressure for a vertically immersed surface lies at a distance equal to __________ the centre of gravity.

A. G / Ax̅ below
B. G / Ax̅ above
C. x̅ / IG below
D. x̅ / IG above
Answer» B. G / Ax̅ above
118.

The dynamic viscosity of gases __________ with rise in temperature.

A. emain unaffected
B. ncreases
C. ecreases
D. one of these
Answer» C. ecreases
119.

The dynamic viscosity of the liquid __________ with rise in temperature.

A. emain unaffected
B. ncreases
C. ecreases
D. one of these
Answer» D. one of these
120.

The pressure measured with the help of a pressure gauge is called

A. tmospheric pressure
B. auge pressure
C. bsolute pressure
D. ean pressure
Answer» C. bsolute pressure
121.

To avoid an interruption in the flow of a siphon, an air vessel is provided

A. t the inlet
B. t the outlet
C. t the summit
D. t any point between inlet and outlet
Answer» D. t any point between inlet and outlet
122.

In a footstep bearing, if the radius of the shaft is doubled, then the torque required to overcome the viscous resistance will be

A. ouble
B. our times
C. ight times
D. ixteen times
Answer» E.
123.

In a footstep bearing, if the speed of the shaft is doubled, then the torque required to overcome the viscous resistance will be

A. ouble
B. our times
C. ight times
D. ixteen times
Answer» B. our times
124.

The coefficient of discharge in case of internal mouthpiece is __________ that of external mouthpiece.

A. ess than
B. ore than
C. qual to
D. one of these
Answer» B. ore than
125.

A vertical wall is subjected to a pressure due to one kind of liquid, on one of its sides. The total pressure on the wall acts at a distance __________ from the liquid surface.

A. /3
B. /2
C. H/3
D. H/4
Answer» D. H/4
126.

The depth of centre of pressure (h) for a vertically immersed surface from the liquid surface is given by (where IG = Moment of inertia of the immersed surface about horizontal axis through its centre of gravity, A = Area of immersed surface, and x = Depth of centre of gravity of the immersed surface from the liquid surface)

A. IG/Ax̅) - x̅
B. IG/x̅) - Ax̅
C. Ax̅/IG) + x̅
D. IG/Ax̅) + x̅
Answer» E.
127.

The total pressure on a horizontally immersed surface is (where w = Specific weight of the liquid, A = Area of the immersed surface, and x = Depth of the centre of gravity of the immersed surface from the liquid surface)

A. A
B. x
C. Ax
D. A/x
Answer» D. A/x
128.

The mercury does not wet the glass. This is due to the property of the liquid known as

A. ohesion
B. dhesion
C. iscosity
D. urface tension
Answer» E.
129.

A turbine is required to develop 1500 kW at 300 r.p.m. under a head of 150 m. Which of the following turbine should be used?

A. elton wheel with one nozzle
B. elton wheel with two or more nozzles
C. aplan turbine
D. rancis turbine
Answer» B. elton wheel with two or more nozzles
130.

According to fan laws, for fans having constant wheel diameter, the pressure varies

A. irectly as fan speed
B. quare of fan speed
C. ube of fan speed
D. quare root of fan speed
Answer» C. ube of fan speed
131.

One cubic metre of water weighs

A. 00 liters
B. 50 liters
C. 00 liters
D. 000 liters
Answer» E.
132.

The discharge through a small rectangular orifice is given by (where Cd = Coefficient of discharge for the orifice, a = Cross-sectional area of the orifice, h = Height of the liquid above the centre of the orifice)

A. = Cd × a × 2gh
B. = (2/3). Cd × a × h
C. = (Cd × a)/√(2gh)
D. = (3Cd × a)/√(2h)
Answer» B. = (2/3). Cd × a × h
133.

The discharge through a wholly drowned orifice is given by (where H1 = Height of water (on the upstream side) above the top of the orifice, H2 = Height of water (on the downstream side) above the bottom of the orifice, and H = Difference between two water levels on either side of the orifice)

A. = Cd × bH₁ × √(2gh)
B. = Cd × bH2 × √(2gh)
C. = Cd × b (H2 - H1) × √(2gh)
D. = Cd × bH × √(2gh)
Answer» D. = Cd × bH × √(2gh)
134.

A weir is said to be broad crested weir, if the width of the crest of the weir is ________ half the height of water above the weir crest.

A. qual to
B. ess than
C. ore than
D. one of these
Answer» D. one of these
135.

A weir is said to be narrow-crested weir, if the width of the crest of the weir is __________ half the height of water above the weir crest.

A. qual to
B. ess than
C. ore than
D. one of these
Answer» C. ore than
136.

When an internal mouthpiece is running free, the discharge through the mouthpiece is (where a = Area of mouthpiece, and H = Height of liquid above the mouthpiece)

A. .5 a. √2gH
B. .707 a. √2gH
C. .855 a. √2gH
D. . √2gH
Answer» B. .707 a. √2gH
137.

The discharge through an external mouthpiece is given by (where a = Cross-sectional area of the mouthpiece, and H = Height of liquid above the mouthpiece)

A. .855 a.√(2gH)
B. .855 aH.√(2g)
C. .585 a.√(2gH)
D. .85 aH.√(2g)
Answer» B. .855 aH.√(2g)
138.

In an internal mouthpiece, the absolute pressure head at vena contracta is __________ the atmospheric pressure head by an amount equal to height of the liquid above the vena contracta.

A. ess than
B. ore than
C. qual to
D. one of these
Answer» B. ore than
139.

In an internal mouthpiece, if the jet after contraction does not touch the sides of the mouthpiece, then the mouthpiece is said to be

A. unning full
B. unning free
C. artially running full
D. artially running free
Answer» C. artially running full
140.

In a broad-crested weir, the discharge is maximum if the head of water on the downstream side of weir is __________ the head of water on the upstream side of weir.

A. qual to
B. ne-third
C. wo-third
D. hree-fourth
Answer» D. hree-fourth
141.

The unit power developed by a turbine is (where P = Power developed by the turbine under a head of water (H).

A. / √H
B. / H
C. / H3/2
D. / H²
Answer» D. / H²
142.

A pitot tube is used to measure the

A. elocity of flow at the required point in a pipe
B. ressure difference between two points in a pipe
C. otal pressure of liquid flowing in a pipe
D. ischarge through a pipe
Answer» B. ressure difference between two points in a pipe
143.

A ship whose hull length is 100 m is to travel at 10 m/sec. For dynamic similarity, at what velocity should a 1:25 model be towed through water?

A. 0 m/sec
B. 5 m/sec
C. m/sec
D. 0 m/sec
Answer» D. 0 m/sec
144.

The resultant upward pressure of the fluid on an immersed body due to its tendency to uplift the submerged body is called

A. p-thrust
B. eaction
C. uoyancy
D. etacentre
Answer» D. etacentre
145.

The center of gravity of the volume of the liquid displaced by an immersed body is called

A. enter of gravity
B. enter of pressure
C. etacenter
D. enter of buoyancy
Answer» E.
146.

When the pressure intensity at a point is more than the local atmospheric pressure, then the difference of these two pressures is called

A. auge pressure
B. bsolute pressure
C. ositive gauge pressure
D. acuum pressure
Answer» D. acuum pressure
147.

The siphon will work satisfactorily, if the minimum pressure in the pipe is __________ vapour pressure of liquid.

A. qual to
B. ess than
C. ore than
D. one of these
Answer» D. one of these
148.

The power produced by the reaction turbine is ________ to the head of water.

A. irectly proportional
B. nversely proportional
C. th power
D. one of these
Answer» B. nversely proportional
149.

The value of coefficient of velocity for a sharp edged orifice __________ with the head of water.

A. ecreases
B. ncreases
C. emain same
D. one of these
Answer» C. emain same
150.

When the Mach number is less than unity, the flow is called

A. ub-sonic flow
B. onic flow
C. uper-sonic flow
D. yper-sonic flow
Answer» B. onic flow