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.

201.

A thick liquid like syrup has a __________ viscosity than a light liquid like water.

A. esser
B. reater
C. ame
D. one of these
Answer» C. ame
202.

In a single casing, multistage pump running at constant speed, the capacity rating is to be slightly lowered. It can be done by

A. esigning new impeller
B. rimming the impeller size to the required size by machining
C. ot possible
D. ome other alterations in the impeller
Answer» C. ot possible
203.

The power transmitted through a pipe is (where w = Specific weight in N/m3, and Q = Discharge in m3/s)

A. × Q × H
B. × Q × hf
C. × Q (H - hf)
D. × Q (H + hf)
Answer» D. × Q (H + hf)
204.

A piece of metal of specific gravity 7 floats in mercury of specific gravity 13.6. What fraction of its volume is under mercury?

A. 0.5
B. 0.4
C. 0.515
D. 0.5
Answer» D. 0.5
205.

The water in a jet propelled boat is drawn through the openings facing the direction of motion of the boat. The efficiency of propulsion is given by

A. V/(vr - v)
B. V/(vr + v)
C. /(vr - v)
D. /(vr + v)
Answer» C. /(vr - v)
206.

The velocity of the liquid flowing through the divergent portion of a Venturimeter

A. emains constant
B. ncreases
C. ecreases
D. epends upon mass of liquid
Answer» D. epends upon mass of liquid
207.

The pressure of the liquid flowing through the divergent portion of a Venturimeter

A. emains constant
B. ncreases
C. ecreases
D. epends upon mass of liquid
Answer» D. epends upon mass of liquid
208.

The velocity corresponding to Reynold number of 2000 is called

A. ub-sonic velocity
B. uper-sonic velocity
C. ower critical velocity
D. igher critical velocity
Answer» D. igher critical velocity
209.

Euler's number is the ratio of __________ force to pressure force.

A. nertia
B. ravity
C. iscous
D. one of these
Answer» B. ravity
210.

The imaginary line drawn in the fluid in such a way that the tangent to any point gives the direction of motion at that point, is known as

A. ath line
B. tream line
C. teak line
D. otential line
Answer» C. teak line
211.

In order to avoid tendency of separation at throat in a Venturimeter, the ratio of the diameter at throat to the diameter of pipe should be

A. /16 to 1/8
B. /8 to 1/4
C. /4 to 1/3
D. /3 to 1/2
Answer» E.
212.

A tank of uniform cross-sectional area (A) containing liquid upto height (H1) has an orifice of cross-sectional area (a) at its bottom. The time required to empty the tank completely will be

A. 2A√H₁)/(Cd × a√2g)
B. 2AH₁)/(Cd × a√2g)
C. 2AH₁3/2)/(Cd × a√2g)
D. 2AH₁²)/(Cd × a√2g)
Answer» B. 2AH₁)/(Cd × a√2g)
213.

According to Chezy's formula, the discharge through an open channel is (where A = Area of flow, C = Chezy's constant, m = Hydraulic mean depth, and i = Uniform slope in bed)

A. × √(m × i)
B. × √(m × i)
C. C × √(m × i)
D. i × √(A × C)
Answer» D. i × √(A × C)
214.

The specific speed of a turbine is given by the equation

A. √P / H3/2
B. √P / H²
C. √P / H5/4
D. √P / H3
Answer» D. √P / H3
215.

The total energy line lies over the centre line of the pipe by an amount equal to

A. ressure head
B. elocity head
C. ressure head + velocity head
D. ressure head - velocity head
Answer» D. ressure head - velocity head
216.

In order that flow takes place between two points in a pipeline, the differential pressure between these points must be more than

A. rictional force
B. iscosity
C. urface friction
D. ll of the above
Answer» E.
217.

The most efficient section of a channel is

A. riangular
B. ectangular
C. quare
D. rapezoidal
Answer» E.
218.

The discharge through a channel of trapezoidal section is maximum when

A. idth of channel at the top is equal to twice the width at the bottom
B. epth of channel is equal to the width at the bottom
C. he sloping side is equal to half the width at the top
D. he sloping side is equal to the width at the bottom
Answer» D. he sloping side is equal to the width at the bottom
219.

The efficiency of a Pelton wheel working under constant head ________ with the increase in power.

A. emain same
B. ncreases
C. ecreases
D. one of these
Answer» C. ecreases
220.

The intensity of pressure on an immersed surface __________ with the increase in depth.

A. oes not change
B. ncreases
C. ecreases
D. one of these
Answer» C. ecreases
221.

A hydraulic accumulator is a device used to store _________ energy which may be supplied to a machine later on.

A. train
B. ressure
C. inetic
D. one of these
Answer» C. inetic
222.

The ratio of the normal force of jet of water on a plate inclined at an angle of 30° as compared to that when the plate is normal to jet, is

A. /√2
B. /2
C.
Answer» C.
223.

According to Manning's formula, the discharge through an open channel is (where M = Manning's constant)

A. × M × m1/2 × i2/3
B. × M × m2/3 × i1/2
C. 1/2 × M2/3 × m × i
D. 2/3 × M1/3 × m × i
Answer» C. 1/2 × M2/3 × m × i
224.

A Piezometer tube is used only for measuring

A. ow pressure
B. igh pressure
C. oderate pressure
D. acuum pressure
Answer» D. acuum pressure
225.

Which of the following instruments is used to measure flow on the application of Bernoulli's theorem?

A. enturimeter
B. rifice plate
C. ozzle
D. ll of the above
Answer» E.
226.

According to Bernoulli's equation

A. + p/w + v²/2g = constant
B. + p/w - v²/2g = constant
C. - p/w + v²/2g = constant
D. - p/w - v²/2g = constant
Answer» B. + p/w - v²/2g = constant
227.

The error in discharge (dQ/Q) to the error in measurement of head (dH/H) over a rectangular notch is given by

A. Q/Q = (1/2) × (dH/H)
B. Q/Q = (3/4) × (dH/H)
C. Q/Q = (dH/H)
D. Q/Q = (3/2) × (dH/H)
Answer» E.
228.

A flow through an expanding tube at constant rate is called

A. teady uniform flow
B. teady non-uniform flow
C. nsteady uniform flow
D. nsteady non-uniform flow
Answer» C. nsteady uniform flow
229.

An average value of coefficient of velocity is

A. 0.62
B. 0.76
C. 0.84
D. 0.97
Answer» E.
230.

Coefficient of discharge Cd is equal to (where Cc = Coefficient of contraction, Cv = Coefficient of velocity, and Cr = Coefficient of resistance)

A. c × Cv
B. c × Cr
C. v × Cr
D. c/Cr
Answer» B. c × Cr
231.

Delivery head of a centrifugal pump is

A. irectly proportional to N
B. nversely proportional to N
C. irectly proportional to N²
D. nversely proportional to N²
Answer» D. nversely proportional to N²
232.

The total head of a liquid particle in motion is equal to

A. ressure head + kinetic head + potential head
B. ressure head - (kinetic head + potential head)
C. otential head - (pressure head + kinetic head)
D. inetic head - (pressure head + potential head)
Answer» B. ressure head - (kinetic head + potential head)
233.

The power transmitted through the nozzle is maximum when the head lost due to friction in the pipe is __________ of the total supply head.

A. ne-half
B. ne-third
C. wo-third
D. one of these
Answer» C. wo-third
234.

A fluid having no viscosity is known as

A. eal fluid
B. deal fluid
C. ewtonian fluid
D. on-Newtonian fluid
Answer» C. ewtonian fluid
235.

In reaction turbine, draft tube is used

A. o transport water downstream without eddies
B. o convert the kinetic energy to flow energy by a gradual expansion of the flow cross-section
C. or safety of turbine
D. o increase flow rate
Answer» C. or safety of turbine
236.

The speed ratio in case of Francis turbine varies from

A. .15 to 0.3
B. .4 to 0.5
C. .6 to 0.9
D. to 1.5
Answer» D. to 1.5
237.

The power developed by a turbine is (where H = Head of water under which the turbine is working)

A. irectly proportional to H1/2
B. nversely proportional to H1/2
C. irectly proportional to H3/2
D. nversely proportional to H3/2
Answer» D. nversely proportional to H3/2
238.

The Thomson's turbine is _________ reaction turbine.

A. n axial flow
B. n inward flow
C. n outward flow
D. mixed flow
Answer» C. n outward flow
239.

Multistage centrifugal pumps are used to obtain

A. igh discharge
B. igh head
C. umping of viscous fluids
D. igh head and high discharge
Answer» C. umping of viscous fluids
240.

The height of a water column equivalent to a pressure of 0.15 MPa is

A. 5.3 m
B. 5.3 m
C. 5.3 m
D. 5.3 m
Answer» B. 5.3 m
241.

The pressure at a point 4 m below the free surface of water is

A. 9.24 kPa
B. 9.24 kPa
C. 9.24 kPa
D. 9.24 kPa
Answer» D. 9.24 kPa
242.

The flow in a pipe is turbulent when Reynold number is

A. ess than 2000
B. etween 2000 and 2800
C. ore than 2800
D. one of these
Answer» D. one of these
243.

The flow in a pipe is neither laminar nor turbulent when Reynold number is

A. ess than 2000
B. etween 2000 and 2800
C. ore than 2800
D. one of these
Answer» C. ore than 2800
244.

The hydraulic gradient line lies over the centre line of the pipe by an amount equal to the

A. ressure head
B. elocity head
C. ressure head + velocity head
D. ressure head - velocity head
Answer» B. elocity head
245.

The critical depth for a channel is given by (where q = Unit discharge (discharge per unit width) through the channel)

A. q/g)1/2
B. q²/g)1/3
C. q³/g)1/4
D. q⁴/g)1/5
Answer» C. q³/g)1/4
246.

The power absorbed (in watts) in overcoming the viscous resistance of a footstep bearing is

A. π³ N² R² /1800 t
B. π³ N² R⁴ /1800 t
C. π³ N² R² /3600 t
D. π³ N² R⁴ /3600 t
Answer» C. π³ N² R² /3600 t
247.

One poise is equal to

A. .1 N-s/m2
B. N-s/m2
C. 0 N-s/m2
D. 00 N-s/m2
Answer» B. N-s/m2
248.

An opening in the side of a tank or vessel such that the liquid surface with the tank is below the top edge of the opening, is called

A. eir
B. otch
C. rifice
D. one of these
Answer» C. rifice
249.

For very high discharge at low pressure such as for flood control and irrigation applications, following type of pump is preferred

A. entrifugal
B. xial flow
C. eciprocating
D. ixed flow
Answer» C. eciprocating
250.

By fitting an air vessel to the reciprocating pump, there is always a saving of work done and subsequently saving of power. The saving in case of a double acting reciprocating pump is

A. 9.2%
B. 8.8%
C. 4.8%
D. 8.4%
Answer» B. 8.8%