Explore topic-wise MCQs in GATE (Mechanical Engineering).

This section includes 2158 Mcqs, each offering curated multiple-choice questions to sharpen your GATE (Mechanical Engineering) knowledge and support exam preparation. Choose a topic below to get started.

1501.

In case of end to end connection of two or more pipes in series, the __________ each pipe.

A. Same rate of flow passes through
B. Head loss is same through
C. Rate of flow in each pipe is proportional to the length of
D. Total flow rate is the sum of flow rate in
Answer» B. Head loss is same through
1502.

Consider two pipes of same length and diameter through which water is passed at the same velocity. The friction factor for rough pipe is f₁ and that for smooth pipe is f₂. Pick out the correct statement.

A. f₁ = f₂
B. f₁ < f₂
C. f₁ > f₂
D. Data not sufficient to relate f₁ & f₂
Answer» D. Data not sufficient to relate f₁ & f₂
1503.

For a particle settling in water at its terminal settling velocity, which of the following is true?

A. Buoyancy = weight + drag
B. Weight = buoyancy + drag
C. Drag = buoyancy + weight
D. Drag = weight
Answer» C. Drag = buoyancy + weight
1504.

When the water is warm, the height to which it can be lifted by a pump

A. Decreases due to reduced viscosity
B. Decreases due to reduced vapour pressure
C. Increases due to increased vapour pressure
D. Decreases due to increased frictional resistance
Answer» C. Increases due to increased vapour pressure
1505.

Hydraulic intensifier is used for increasing the

A. Rate of velocity of liquid supply
B. Rate of flow through delivery pipeline of a pump
C. Intensity of pressure of the liquid
D. Momentum rate through delivery pipe
Answer» D. Momentum rate through delivery pipe
1506.

Vena-contracta formed during flow of a liquid through an orificemeter has

A. Minimum liquid cross-section
B. More diameter compared to orifice diameter
C. Minimum velocity of fluid stream
D. None of these
Answer» B. More diameter compared to orifice diameter
1507.

Drag co-efficient for motion of spherical particles in a stationary fluid in the stoke's law range is

A. 24/NRe,p
B. 16/NRe,p
C. 64/NRe,p
D. 48/NRe,p
Answer» B. 16/NRe,p
1508.

In centrifugal pump operation, the cavitation can be eliminated by maintaining suction pressure __________ the vapor pressure of the liquid at the suction temperature.

A. Lower than
B. Higher than
C. Equal to
D. None of these
Answer» C. Equal to
1509.

In turbulent flow, a rough pipe has the same friction factor as a smooth pipe

A. In the zone of complete turbulence
B. When the roughness projections are much smaller than the thickness of the laminar film
C. Everywhere in the transition zone
D. When the friction factor is independent of the Reynold's number
Answer» C. Everywhere in the transition zone
1510.

Power required by a centrifugal pump is proportional to (where, D = diameter, N = r.p.m)

A. N²D³
B. ND²
C. N²D
D. N³D⁵
Answer» E.
1511.

In open channel flow in a rectangular channel, the ratio between the critical depth and the initial depth, when a hydraulic jump occurs is

A. 0.5
B. 0.84
C. 1.84
D. 1.25
Answer» D. 1.25
1512.

For flow through an orifice from a reservoir, the actual velocity at the vena con-tracta is given by

A. √(2gh)
B. C.V. √(2gh)
C. Cd √(2gh)
D. Cc √(2gh)
Answer» C. Cd √(2gh)
1513.

A Pitot tube indicates 5 cm of water (manometer) when it is being used for measuring velocity of air. The velocity of air in m/sec is

A. 5
B. 14.1
C. 56.22
D. 28.2
Answer» E.
1514.

Foot valve provided in the pump is a __________ valve.

A. Direction control
B. Back pressure
C. Relief
D. Pressure reduction
Answer» C. Relief
1515.

One stoke (unit of kinematic viscosity) is equivalent to

A. 1 cm²/second
B. 1 m²/second
C. 1 gm/cm. second
D. 1 kg . m/second
Answer» B. 1 m²/second
1516.

Weber number is the ratio of inertial force to __________ force.

A. Surface tension
B. Gravity
C. Viscous
D. Elastic
Answer» B. Gravity
1517.

A pipe of I.D. 4 m is bifurcated into two pipes of I.D. 2 m each. If the average velocity of water flowing through the main pipe is 5 m/sec, the average velocity through the bifurcated pipes is

A. 20 m/sec
B. 10 m/sec
C. 5√2 m/sec
D. 5 m/sec
Answer» C. 5√2 m/sec
1518.

A special type of liquid transporting device is the diffuser pump, in which __________ are minimised.

A. Bearing losses
B. Disk friction
C. Shock losses
D. Cavitation
Answer» D. Cavitation
1519.

The location of centre of pressure, which defines the point of application of the total pressure force on the surface, can be calculated by applying the principle of moments according to which "sum of the moment of the resultant force about an axis is equal to the sum of the components about the same axis". The centre of pressure of a rectangular surface (of width 'w') immersed vertically in a static mass of fluid is at a depth of(where, y = depth of the liquid)

A. 1/3y
B. 2y/3
C. 1/4y
D. 3y/4
Answer» C. 1/4y
1520.

Umf is the minimum fluidisation velocity for a bed of particles. An increase in the superficial gas velocity from 2 Umf to 2.5 Umf results in (all velocities are smaller than the entrainment velocity of the particles) no change in the

A. Drag on particles
B. Drag on coloumn walls
C. Bed height
D. Bed voidage
Answer» D. Bed voidage
1521.

Stoke's law is valid, when the particle Reynolds number is

A. < 1
B. > 1
C. < 5
D. None of these
Answer» B. > 1
1522.

Which of the following has the maximum compression ratio?

A. Blower
B. Compressor
C. Vacuum pump
D. Fan
Answer» D. Fan
1523.

In Newton's law range, the terminal velocity of a solid spherical particle falling through a stationary fluid mass varies as the __________ of its diameter.

A. Inverse
B. Square root
C. Second power
D. First power
Answer» C. Second power
1524.

In case of a rotameter, the density of the float material is __________ that of the liquid it replaces.

A. More than
B. Less than
C. Equal to
D. Either A or B
Answer» B. Less than
1525.

The ratio of the depth of flow to the diameter of the channel for maximum discharge in a circular channel in open channel flow is

A. 0.1
B. 0.55
C. 0.95
D. 1.85
Answer» D. 1.85
1526.

The line of action of the buoyant force passes through the centre of gravity of the

A. Submerged body
B. Displaced volume of the fluid
C. Volume of fluid vertically above the body
D. Horizontal projection of the body
Answer» C. Volume of fluid vertically above the body
1527.

The boundary layer thickness at a given section along a flat plate __________ with increasing Reynold's number.

A. Increases
B. Decreases
C. Remains same
D. May increase or decrease
Answer» C. Remains same
1528.

The discharge through a rectangular weir varies as

A. H1/2
B. H5/2
C. H2/5
D. H3/2
Answer» E.
1529.

Pick out the correct statement pertaining to the flow through a converging-diverging tube.

A. The value of Mach number is always unity at the throat
B. No shock wave develops in the tube when the Mach number at exit is greater than unity
C. Throughout the converging portion of the tube, the density increases in the downstream direction
D. None of these
Answer» C. Throughout the converging portion of the tube, the density increases in the downstream direction
1530.

Diaphragm pumps are used to transport

A. Solids
B. Liquids
C. Fluids
D. Slurries
Answer» E.
1531.

The maximum head that can be developed by a single impeller is __________ ft.

A. 25
B. 100
C. 250-300
D. 1000
Answer» D. 1000
1532.

Glass pipes can be joined by

A. Flanges
B. Welding
C. Soldering
D. Bell and spigot joint
Answer» E.
1533.

Surge tanks are provided in high pressure water pipelines to

A. Store a definte quantity ofwater all the time
B. Reduce the water hammer
C. Facilitate easy dismantling of pipeline for cleaning and maintenance
D. None of these
Answer» C. Facilitate easy dismantling of pipeline for cleaning and maintenance
1534.

The discharge through a venturimeter depends upon

A. Pressure drop only
B. Its orientation
C. Co-efficient of contraction only
D. None of these
Answer» B. Its orientation
1535.

Gear pump

A. Is a positive displacement pump
B. Is a centrifugal pump
C. Is a non-positive displacement pump
D. Can be started with delivery valve closed
Answer» B. Is a centrifugal pump
1536.

What is the shear rate at the pipe wall, in case of laminar flow of Newtonion fluids in a pipe of diameter 'D' & length 'L' incurring a pressure drop 'Δp' with average velocity 'Vavg'?

A. D Δp/8L
B. D Δp/4L
C. 8 . Vavg/D
D. 4 . Vavg/D
Answer» D. 4 . Vavg/D
1537.

The percentage slip in a reciprocating pump set is given by the % of (where, Q₁ = actual discharge Q₂ = theoretical discharge)

A. Q₁/Q₂
B. Q₂/Q₁
C. (Q₂ - Q₁)/Q₁
D. (Q₂ - Q₁)/Q₂
Answer» E.
1538.

The general relationship between speed N, head H, power P and discharge Q for a centrifugal pump is

A. Q∝N : H∝N² : P∝N³
B. Q∝N² : H∝N³ : P∝N
C. Q∝N : H∝N³ : P∝N²
D. Q∝N³ : H∝N : P∝N²
Answer» B. Q∝N² : H∝N³ : P∝N
1539.

Centrifugal pump can't be used to pump

A. Molten sodium (used as a coolant in Fast Breeder Reactor)
B. Moderately viscous vegetable oil used in soap industry
C. Thick molten soap at 80°C
D. None of the above
Answer» D. None of the above
1540.

Water flow rate in a pipe of 3.5 metres diameter can be most economically and conveniently measured by a/an

A. Pitot tube
B. Venturimeter
C. Orificemeter
D. Rotameter
Answer» B. Venturimeter
1541.

With the increase in depth, the hydrostatic pressure in an unaccelerated incompressible fluid (in a constant gravitational field)

A. Decreases
B. Increases linearly
C. Increases exponentially
D. Remains constant
Answer» C. Increases exponentially
1542.

For pipes that must be broken at intervals for maintenance, the connector used should be a/an

A. Union
B. Tee
C. Reducer
D. Elbow
Answer» B. Tee
1543.

Mass velocity in case of steady flow and through a constant cross-section conduit is independent of the

A. Temperature
B. Pressure
C. Both A & B
D. Neither A nor B
Answer» D. Neither A nor B
1544.

Reciprocating pumps compared to centrifugal pumps

A. Deliver liquid at uniform pressure
B. Can handle slurries more efficiently
C. Are not subject to air binding
D. Can be operated with delivery valve closed
Answer» D. Can be operated with delivery valve closed
1545.

A gas (density = 1.5 kg/m³ , viscosity = 2x 10⁻⁵ kg/m.s) flowing through a packed bed (particle size = 0.5 cm, porosity = 0.5) at a superficial velocity of 2 m/s causes a pressure drop of 8400 Pa/m. The pressure drop for another gas, with density of 1.5kg/m³and viscosity of 3 x 10⁻⁵kg/m.s flowing at 3 m/s will be

A. 8400 Pa/m
B. 12600 Pa/m
C. 18900 Pa/m
D. 16800 Pa/m
Answer» C. 18900 Pa/m
1546.

During ageing of fluid carrying pipes, the

A. Pipe becomes smoother with use
B. Friction factor increases linearly with time
C. Absolute roughness decreases with time
D. Absolute roughness increases linearly with time
Answer» E.
1547.

Disc compensators are provided in large diameter fuel gas carrying pipelines to

A. Keep the pipe in proper orientation
B. Make the pipe joint leak-proof
C. Account for contraction/expansion of pipe due to temperature changes of the surroundings
D. Account for the pressure variation side the pipeline
Answer» D. Account for the pressure variation side the pipeline
1548.

Applicability of Bernoulli's equation is limited to a/an __________ fluid, that does not exchange shaft work with the surroundings.

A. Incompressible
B. Non-viscous
C. Both A and B
D. Neither A nor B
Answer» D. Neither A nor B
1549.

Froude number is the ratio of

A. Shear stress to gravitational stress
B. Drag stress to shear stress
C. Inertial stress to shear stress
D. Inertial stress to gravitational stress
Answer» E.
1550.

Froude number is not a factor

A. For Reynolds number greater than 300
B. When there is no vortex formation
C. For unbaffled tank
D. None of these
Answer» C. For unbaffled tank