MCQOPTIONS
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MCQOPTIONS
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.
| 851. |
What is positive suction head? |
| A. | Draft tube is above |
| B. | Pump pressure is above |
| C. | Liquid level is above |
| D. | Turbine head is above View Answer |
| Answer» D. Turbine head is above View Answer | |
| 852. |
What is a major advantage of centrifugal pump? |
| A. | Cost |
| B. | Simple in construction |
| C. | Efficiency |
| D. | Pump parameters View Answer |
| Answer» C. Efficiency | |
| 853. |
The simple elbow draft tube is placed close to the_ |
| A. | Head race |
| B. | Tail race |
| C. | Tank |
| D. | Nozzle |
| Answer» C. Tank | |
| 854. |
Jet propulsion of ship is less efficient than screw propeller due to |
| A. | Pressure |
| B. | Temperature |
| C. | Frictional losses |
| D. | Wear and tear |
| Answer» D. Wear and tear | |
| 855. |
The force analysis on a curved vane is understood using |
| A. | Velocity triangles |
| B. | Angle of the plate |
| C. | Vane angles |
| D. | Plate dimensions |
| Answer» B. Angle of the plate | |
| 856. |
Hydraulic head is also called as |
| A. | Pressure head |
| B. | Density head |
| C. | Kinetic head |
| D. | Piezometric head |
| Answer» E. | |
| 857. |
A pipe has a porous section of length L as shown in the figure. Velocity at the start of this section of V0. If fluid leaks into the pipe through the porous section at a volumetric rate per unit area q(x/L)2, what will be axial velocity in the pipe at any x ? Assume incompressible one dimensional flow i.e., no gradients in the radial direction. |
| A. | [A]. |
| B. | [B]. |
| C. | [C]. |
| D. | [D]. |
| Answer» E. | |
| 858. |
The Kozney-Carman equation, rewritten in terms of non-dimensional numbers gives (ΔP/pu2 ) proportional to |
| A. | [A]. |
| B. | [B]. |
| C. | [C]. |
| D. | [D]. |
| Answer» B. [B]. | |
| 859. |
A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun's equation for the above fluid-particle system (in SI units) is given below : Δ P/L = 375 x 103 VOM + 10.94 x 106 V2OM (SI units) If water is to be used as the fluidising medium, in actual operation, the above bed has a height = 1 m. What is the porosity of the fluidised bed ? |
| A. | 0.2 |
| B. | 0.5 |
| C. | 0.7 |
| D. | 0.8 |
| Answer» D. 0.8 | |
| 860. |
A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun's equation for the above fluid-particle system (in SI units) is given below : Δ P/L = 375 x 103 VOM + 10.94 x 106 V2OM (SI units) If water is to be used as the fluidising medium, the minimum fluidisation velocity, VOM is |
| A. | 12 mm/s |
| B. | 16 mm/s |
| C. | 24 mm/s |
| D. | 28 mm/s |
| Answer» C. 24 mm/s | |
| 861. |
A Bingham fluid of viscosity μ = 10 Pa.s and yield stress, τ0 = 10 KPa, is shared between flat parallel plates separated by a distance of 10-3 m. The top plate is moving with a velocity of 1 m/s. The shear stress on the plate is |
| A. | 10 KPa |
| B. | 20 KPa |
| C. | 30 KPa |
| D. | 40 KPa |
| Answer» C. 30 KPa | |
| 862. |
A free jet of water of cross-sectional area 0.01m2 and a velocity of 20 m/s strikes a plate and then flows in a plane parallel to the plate as shown in the figure below. The horizontal component of the force on the support is |
| A. | 200 N |
| B. | 400 N |
| C. | 2000 N |
| D. | 4000 N |
| Answer» E. | |
| 863. |
Bed pressure drop in an air fluidised bed of catalyst particles (ρp = 200 kg/m3, Dp = 0.05 cm) of 60 cm bed depth and bed porosity of 0.5 expressed in cm of water (manometer) is |
| A. | 90 |
| B. | 60 |
| C. | 45 |
| D. | 30 |
| Answer» C. 45 | |
| 864. |
Hydraulic mean radius for flow through packed bed of spherical particle of size, 'Dp, with porosity 'ε' is |
| A. | [A]. |
| B. | [B]. |
| C. | [C]. |
| D. | [D]. |
| Answer» B. [B]. | |
| 865. |
During fluid flow, variation of shear stress(τ) with velocity gradientat constant pressure temperature is shown below in the figure In the above figure, Binghom plastic is represented by the curve . |
| A. | V |
| B. | II |
| C. | III |
| D. | I |
| Answer» C. III | |
| 866. |
Which of the following equations as suggested by Colebrook and White gives the increase in roughness of a new surface (ε0) with age/time (t) (where, ε = roughness of the surface after time't'. α = a co-efficient to be experimentally determined)? |
| A. | ε = ε0 + α.t |
| B. | ε = ε0 + α.t2 |
| C. | ε = ε0 + α.t3 |
| D. | ε = ε0 + α.t4 |
| Answer» B. ε = ε0 + α.t2 | |
| 867. |
What is the ratio of fluid carrying capacity of two pipes having diameters d1 and d2 respectively ? |
| A. | [A]. |
| B. | [B]. |
| C. | [C]. |
| D. | [D]. |
| Answer» C. [C]. | |
| 868. |
__________ pump is the most suitable device for discharging a liquid against a pressure of ≥ 1500 kgf/cm2. |
| A. | Centrifugal |
| B. | Piston |
| C. | Plunger |
| D. | Vane |
| Answer» D. Vane | |
| 869. |
Drag co-officient CD, in Stoke's law range is given by |
| A. | [A]. |
| B. | [B]. |
| C. | [C]. |
| D. | [D]. |
| Answer» C. [C]. | |
| 870. |
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. | [C]. |
| D. | [D]. |
| Answer» E. | |
| 871. |
Various efficiencies of a centrifugal pump are related as (where, ηm = mechanical efficiency ηv = volumetric efficiency. ηma = manometric efficiency ηo = overall efficiency) |
| A. | ηma x ηm x ηv = ηo |
| B. | ηm = ηv . ηma |
| C. | ηma = ηm x ηv |
| D. | ηv = ηm x ηma |
| Answer» C. ηma = ηm x ηv | |
| 872. |
Pick out the Blake-Plummer equation (valid for large NRe) for fluid flow through beds of solids. |
| A. | [A]. |
| B. | [B]. |
| C. | [C]. |
| D. | [D]. |
| Answer» E. | |
| 873. |
Pick out the Kozney-Karman equation (valid for low NRe) for fluid flow through a packed bed of solids. |
| A. | [A]. |
| B. | [B]. |
| C. | [C]. |
| D. | [D]. |
| Answer» D. [D]. | |
| 874. |
A centrifugal pump has the following specifications: Power = 4 H.P.; Speed = 800 rpmHead = 8 metresFlow = 1000 litres/minutes.If its speed is halved, then the new head will be __________ metres. |
| A. | 2 |
| B. | 4 |
| C. | 8 |
| D. | 5.5 |
| Answer» B. 4 | |
| 875. |
Bed pressure drop in an air fluidised bed of catalyst particles (ρₚ = 200 kg/m³, Dₚ = 0.05 cm) of 60 cm bed depth and bed porosity of 0.5 expressed in cm of water (manometer) is |
| A. | 90 |
| B. | 60 |
| C. | 45 |
| D. | 30 |
| Answer» C. 45 | |
| 876. |
Which of the following is a dimensionless parameter ? |
| A. | Angular velocity |
| B. | Specific weight |
| C. | Kinematic viscosity |
| D. | None of these |
| Answer» E. | |
| 877. |
N²ʀₑ/Nғᵣ is called the __________ number. |
| A. | Brinkman |
| B. | Galileo |
| C. | Archimedes |
| D. | Euler |
| Answer» C. Archimedes | |
| 878. |
The variable required to be known in correlations used for estimating the horse power of a centrifugal gas compressor and hence its cost are P. Inlet pressureQ. Compressor rpmR. Delivery pressureS. Volumetric flow rate at inlet. |
| A. | P, Q and R |
| B. | P and R |
| C. | R and S |
| D. | P, Rand S |
| Answer» B. P and R | |
| 879. |
A fluid element has a velocity V = -y² . xi + 2yx² . j. The motion at (x, y) = (l/√2, 1) is |
| A. | rotational and incompressible |
| B. | rotational and compressible |
| C. | irrotational and compressible |
| D. | irrotational and incompressible |
| Answer» C. irrotational and compressible | |
| 880. |
In a fully turbulent flow (Re > 10⁵) in a pipe of diameter 'd', for a constant pressure gradient, the dependence of volumetric flow rate of an incompressible fluid is |
| A. | d |
| B. | d² |
| C. | d^2.5 |
| D. | d⁴ |
| Answer» D. d⁴ | |
| 881. |
A centrifugal pump has the following specifications: Power = 4 H.P. Speed = 800 rpmHead = 8 metresFlow = 1000 litres/minutes.If its speed is halved, the new discharge will be __________ litres/minute. |
| A. | 500 |
| B. | 200 |
| C. | 1000 |
| D. | 750 |
| Answer» B. 200 | |
| 882. |
In which type of fluid flow, the velocity of flow of fluid changes from point to point in the fluid at any instant ? |
| A. | Rotational |
| B. | Unsteady |
| C. | Turbulent |
| D. | Non-uniform |
| Answer» E. | |
| 883. |
Horsepower increase of a centrifugal gas compressor without altering the volumetric flow rate will __________ the gas discharge pressure. |
| A. | increase |
| B. | decrease |
| C. | not change |
| D. | exponentially decrease |
| Answer» B. decrease | |
| 884. |
A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun's equation for the above fluid-particle system (in SI units) is given below : Δ P/L = 375 x 10³ Vₒₘ + 10.94 x 10⁶ V²ₒₘ (SI units) If water is to be used as the fluidising medium, in actual operation, the above bed has a height = 1 m. What is the porosity of the fluidised bed ? |
| A. | 0.2 |
| B. | 0.5 |
| C. | 0.7 |
| D. | 0.8 |
| Answer» D. 0.8 | |
| 885. |
The drag co-efficient for a bacterium moving in water at 1 mm/s, will be of the following order of magnitude (assume size of the bacterium to be 1 micron and kinematic viscosity of water to be 10⁻⁶ m²/s). |
| A. | 24000 |
| B. | 24 |
| C. | 0.24 |
| D. | 0.44 |
| Answer» E. | |
| 886. |
What is the ratio of the velocity at the axis of the pipe to the mean velocity of flow in case of pipe flow under viscous condition ? |
| A. | 0.5 |
| B. | 0.67 |
| C. | 1 |
| D. | 2 |
| Answer» E. | |
| 887. |
Which of the following relationship is valid for the equilibrium position of the float in a rotameter ? (where, Df = Drag force on the float Bf = Buoyant force on the float Wf = Weight of the float) |
| A. | Df + Bf = Wf |
| B. | Df = Bf + Wf |
| C. | Df + Bf + Wf =0 |
| D. | none of these |
| Answer» B. Df = Bf + Wf | |
| 888. |
Which of the following is the most common pump for pumping either raw sewage or sludge ? |
| A. | Electromagnetic pump |
| B. | Centrifugal pump |
| C. | Reciprocating pump |
| D. | Gear pump |
| Answer» D. Gear pump | |
| 889. |
Which of the fluid forces are not considered in the Reynold's equation of flow ? |
| A. | Viscous forces |
| B. | Turbulent forces |
| C. | Pressure forces |
| D. | Compressibility forces |
| Answer» E. | |
| 890. |
A centrifugal pump has the following specifications: Power = 4 H.P. Speed = 800 rpmHead = 8 metresFlow = 1000 litres/minutes.If its speed is halved, the power consumed now will be __________ hp. |
| A. | 0.5 |
| B. | 2 |
| C. | 4 |
| D. | 1 |
| Answer» B. 2 | |
| 891. |
Which of the following facilitates close control of flow of fluids ? |
| A. | Gate valve |
| B. | Globe valve |
| C. | Butterfly valve |
| D. | Check valve |
| Answer» C. Butterfly valve | |
| 892. |
Fanning friction factor is equal to (where, fʙ = Blassius friction factor). |
| A. | fʙ/4 |
| B. | fʙ/2 |
| C. | 4fʙ |
| D. | 2fʙ |
| Answer» B. fʙ/2 | |
| 893. |
In case of turbulent flow of a Newtonion fluid in a straight pipe, the maximum velocity is equal to (where, Vavg = average fluid velocity) |
| A. | Vavg |
| B. | 1.2 Vavg |
| C. | 1.5 Vavg |
| D. | 1.8 Vavg |
| Answer» C. 1.5 Vavg | |
| 894. |
Upto what value of 'Mach number', a fluid may be considered as incompressible ? |
| A. | 0.03 |
| B. | 0.3 |
| C. | 3 |
| D. | 10 |
| Answer» C. 3 | |
| 895. |
The equation relating friction factor to Reynold number, f^-0.5 = 4 logₑ (Nʀₑ/√f)^-0.4, is called the __________ equation. |
| A. | Nikuradse |
| B. | Von-Karman |
| C. | Blausius |
| D. | Colebrook |
| Answer» B. Von-Karman | |
| 896. |
f = 16/Nʀₑ, is valid for |
| A. | turbulent flow |
| B. | laminar flow through an open channel |
| C. | steady flow |
| D. | none of these |
| Answer» E. | |
| 897. |
Which of the following is not concerned with the fluid-particle interaction ? |
| A. | Drag co-efficient |
| B. | Froude number |
| C. | Galileo number |
| D. | Weber number |
| Answer» E. | |
| 898. |
Which is not a variable head meter ? |
| A. | Venturimeter |
| B. | Pitot tube |
| C. | Rotameter |
| D. | None of these |
| Answer» D. None of these | |
| 899. |
Mach number is defined as the ratio of the local flow velocity to the sonic velocity in the fluid. For what value of Mach number, the gases are considered incompressible ? |
| A. | < 0.3 |
| B. | > 3 |
| C. | 50 |
| D. | 1 |
| Answer» B. > 3 | |
| 900. |
What causes cavitation in centrifugal pump ? |
| A. | High suction pressure |
| B. | Low barometric pressure |
| C. | Low suction pressure |
| D. | High suction velocity |
| Answer» D. High suction velocity | |