280+ Fluid Mechanics and Machinery Solved MCQs

201.

Which among the following does not depend on the friction factor?

A. pipe diameter
B. fluid density
C. viscosity
D. weight
Answer» D. weight
202.

Darcy- Weisbach equation gives relation between                     

A. pressure and temperature
B. mass, volume and pressure
C. head loss and pressure loss
D. pressure loss only
Answer» C. head loss and pressure loss
203.

Loss of head due to friction is                      

A. directly proportional to hydraulic radius
B. inversely proportional to velocity
C. inversely proportional to hydraulic radius
D. directly proportional to gravitational constant
Answer» C. inversely proportional to hydraulic radius
204.

The formula for hydraulic diameter is             

A. 4a/p
B. 4ap
C. 4av
D. 4v
Answer» A. 4a/p
205.

Relative roughness is                   

A. ϵ/d
B. ϵ*d
C. ϵ/dm
D. ϵgd
Answer» A. ϵ/d
206.

The liquid flowing through a series of pipes can take up                     

A. pipes of different diameters
B. pipes of the same diameters only.
C. single pipe only
D. short pipes only
Answer» A. pipes of different diameters
207.

The total head loss for the system is equal to                   

A. pipe length
B. pipe diameter
C. width of the reservoir
D. height difference of reservoirs
Answer» D. height difference of reservoirs
208.

Which among the following is not a loss that is developed in the pipe?

A. entry
B. exit
C. connection between two pipes
D. liquid velocity
Answer» D. liquid velocity
209.

If the two reservoirs are kept at the same level, the head loss is                

A. z1-z2
B. zero
C. t2-t1
D. s2-s1
Answer» B. zero
210.

The pipe diameter is                  

A. directly proportional to fluid density
B. directly proportional to mass flow rate
C. inversely proportional to mass flow rate
D. directly proportional to fluid velocity
Answer» B. directly proportional to mass flow rate
211.

Coefficient of friction of a laminar flow is                   

A. re/16
B. re/64
C. 16/re
D. 64/re
Answer» C. 16/re
212.

1 NEED FOR DIMENSIONAL ANALYSIS - METHODS OF DIMENSIONAL ANALYSIS

A. botanical science
B. zoological science
C. chemistry
D. physics
Answer» C. chemistry
213.

Similitude is a concept applicable to the testing of                    

A. mathematical models
B. physical models
C. engineering models
D. chemical models
Answer» C. engineering models
214.

A model of with same shape is                     

A. geometric similarity
B. kinematic similarity
C. dynamic similarity
D. conditional similarity
Answer» A. geometric similarity
215.

All the parameters in a similitude are described using                   

A. continuum mechanics
B. solid mechanics
C. diesel mechanics
D. aircraft mechanics
Answer» A. continuum mechanics
216.

The rate at which the particles of fluid can spread is called               

A. surface tension
B. diffusivity
C. viscosity
D. kinetics
Answer» B. diffusivity
217.

The Prandtl Number approximates

A. momentum diffusivity to thermal diffusivity
B. thermal diffusivity to momentum diffusivity
C. shear stress to thermal diffusivity
D. thermal diffusivity to kinematic viscosity
Answer» A. momentum diffusivity to thermal diffusivity
218.

Which among the following is the standard symbol for Atwood number?

A. a
B. ar
C. ar
D. a
Answer» A. a
219.

Fanning friction factor is                    

A. 0.25 times darcy friction factor
B. same as darcy friction factor
C. 2 times darcy friction factor
D. independent
Answer» A. 0.25 times darcy friction factor
220.

Which among the following is the standard symbol for Froude number?

A. f
B. fo
C. fr
D. f
Answer» C. fr
221.

Principle of fluid mechanics works on the utilization of                 

A. accelerating mass
B. volume
C. work
D. velocity
Answer» C. work
222.

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» A. velocity triangles
223.

Jet propulsion works on the principle of                 

A. newton’s first law
B. newton’s second law
C. newton’s third law
D. thermodynamic properties
Answer» C. newton’s third law
224.

The relative velocity is obtained by the equation                   

A. u – v1
B. v1
C. u*v1
D. u/v1
Answer» A. u – v1
225.

If the friction is neglected, then               

A. vr1 > vr2
B. vr1 < vr2
C. vr1 = vr2
D. vr1 is a zero
Answer» C. vr1 = vr2
226.

Through inlet orifices, which are facing the direction of motion of the ship, the water from the sea can be taken by the pump.

A. true
B. false
Answer» A. true
227.

Jet propulsion of ship is less efficient than screw propeller due to               

A. pressure
B. temperature
C. frictional losses
D. wear and tear
Answer» C. frictional losses
228.

A jet strikes a curved plate at its              

A. sides
B. surface
C. centre
D. does not strike
Answer» C. centre
229.

Which among the following is not a type of jet engine?

A. turbojet
B. ramjet
C. scramjet
D. propulsive jet
Answer» D. propulsive jet
230.

The fluid gains                    while passing through the impeller.

A. velocity
B. pressure
C. temperature
D. velocity and pressure
Answer» D. velocity and pressure
231.

What is the shape of the diffuser in the centrifugal pump?

A. round
B. dough nut
C. rectangle
D. cylindrical
Answer» B. dough nut
232.

When the casing in a centrifugal pump decelerates the flow, what increases?

A. pressure
B. temperature
C. volume
D. flow rate
Answer» A. pressure
233.

The velocity imparted by the impeller is converted into                    

A. pressure energy
B. kinetic energy
C. momentum
D. potential energy
Answer» A. pressure energy
234.

The consequence of Newtons second law is                   

A. conservation of angular momentum
B. conservation of mass
C. conservation of potential energy
D. conservation of kinetic energy
Answer» A. conservation of angular momentum
235.

Euler developed the head pressure equation in centrifugal pumps.

A. true
B. false
Answer» A. true
236.

What is a major advantage of centrifugal pump?

A. cost
B. simple in construction
C. efficiency
D. pump parameters
Answer» B. simple in construction
237.

Different velocities in a centrifugal pump are determined by using                  

A. velocity triangle
B. reynolds number
C. froude number
D. overall efficiency
Answer» A. velocity triangle
238.

With the increase in the input power, efficiency                

A. increases
B. decreases
C. same
D. independent
Answer» B. decreases
239.

Turbomachines work under                  

A. newtons first law
B. newtons second law
C. newtons third law
D. kepler’s law
Answer» B. newtons second law
240.

The main function of nozzle is to

A. pump start procedure                      
B. positive start pump
C. pump start pointer
D. positive start pointer
Answer» A. pump start procedure                      
241.

The main function of centrifugal pumps are to                  

A. transfer speed
B. transfer pressure
C. transfer temperature
D. transfer energy
Answer» D. transfer energy
242.

The inlet passage of water entry is controlled by                  

A. head race
B. gate
C. tail race
D. pump
Answer» B. gate
243.

Centrifugal pumps transport fluids by converting                    

A. kinetic energy to hydrodynamic energy
B. hydrodynamic energy to kinetic energy
C. mechanical energy to kinetic energy
D. mechanical energy to hydrodynamic energy
Answer» A. kinetic energy to hydrodynamic energy
244.

With the increase in load, Energy in the turbine                 

A. decreases
B. increases
C. remains same
D. independent
Answer» A. decreases
245.

When the balancing of the turbine is disturbed, we use                  

A. throttle governing
B. steam governing
C. nozzle governing
D. emergency governing
Answer» D. emergency governing
246.

The fluid coming into the centrifugal pump is accelerated by                  

A. throttle
B. impeller
C. nozzle
D. governor
Answer» B. impeller
247.

Reciprocating pump is a                  

A. negative displacement pump
B. positive displacement pump
C. diaphragm pump
D. emulsion pump
Answer» B. positive displacement pump
248.

The cylinder of reciprocating cylinder is made up of                

A. cast iron
B. wrought iron
C. aluminium
D. copper
Answer» A. cast iron
249.

The higher discharge valve line holds the discharge valve                  

A. open
B. closed
C. stop functioning
D. automatic
Answer» B. closed
250.

Reciprocating pumps are also called as

A. force pumps
B. mass pumps
C. heat pumps
D. speed pumps
Answer» A. force pumps
251.

Reciprocating pumps are classified according to                        

A. drag force
B. number of cylinders
C. shock waves
D. flow speed
Answer» B. number of cylinders
252.

Simple hand operating pump is also called as              

A. froth pump
B. bicycle pump
C. multistage pumps
D. centrifugal pumps
Answer» B. bicycle pump
253.

Internal cavitation in reciprocating pumps occurs due to                      

A. drag force
B. cyclic stress
C. shock waves
D. flow speed
Answer» C. shock waves
254.

Operation of reciprocating motion is done by a                  source

A. power
B. energy
C. momentum
D. inertia
Answer» A. power
255.

High pressure reciprocating pumps are generally from 1500 HP.

A. true
B. false
Answer» A. true
256.

Which of the following centrifugal pumps has higher specific speed than the others?

A. axial flow
B. radial flow
C. mixed flow
D. all centrifugal pumps have same specific speed
Answer» A. axial flow
257.

Pump transfers the mechanical energy of a motor or of an engine into                    of a fluid.

A. pressure energy
B. kinetic energy
C. either pressure energy or kinetic energy
D. pressure energy, kinetic energy or both
Answer» D. pressure energy, kinetic energy or both
258.

Which of the following is NOT a type of positive displacement pumps?

A. reciprocating pump
B. rotary displacement pump
C. centrifugal pump
D. none of the mentioned
Answer» C. centrifugal pump
259.

Rotary displacement pumps are suitable for handling                  

A. oils
B. gritty liquids
C. both oils as well as gritty liquids
D. granules
Answer» A. oils
260.

Which of the following is/are not example/s of rotary displacement pumps?

A. gear pump
B. vane pump
C. rotary piston pump
D. centrifugal pump
Answer» D. centrifugal pump
261.

                       pump is also called as velocity pump.

A. reciprocating
B. rotary displacement
C. centrifugal
D. screw
Answer» C. centrifugal
262.

Discharge capacity of the reciprocating pump is                      that of the centrifugal pump.

A. higher than
B. lower than
C. same as
D. unpredictable
Answer» B. lower than
263.

The process of filling the liquid into the suction pipe and pump casing up to the level of delivery valve is called as                    

A. filling
B. pumping
C. priming
D. leveling
Answer» C. priming
264.

Main application of liquid ring pump is in which of the following?

A. low viscosity products
B. heavily aerated liquids
C. gentle treatment with high viscosity
D. water treatment
Answer» B. heavily aerated liquids
265.

What is the water flow direction in the runner in a Francis turbine?

A. axial and then tangential
B. tangential and then axial
C. radial and then axial
D. axial and then radial
Answer» C. radial and then axial
266.

Which of the following runner types will have the highest vane angle at inlet (β1 value)?

A. slow runner
B. medium runner
C. fast runner
D. vane angle is defined only for kaplan turbines and not francis turbines
Answer» C. fast runner
267.

2 AXIAL, RADIAL AND MIXED FLOW TURBINES.

A. guide vane angle at inlet
B. blade angle at inlet
C. vane angle at inlet
D. blade angle at outlet
Answer» A. guide vane angle at inlet
268.

A hydraulic coupling belongs to the category of                 

A. energy absorbing machines
B. energy generating machines
C. power absorbing machines
D. energy transfer machines
Answer» D. energy transfer machines
269.

The electric power which is obtained from hydraulic energy                         

A. thermal power
B. mechanical power
C. solar power
D. hydroelectric power
Answer» D. hydroelectric power
270.

At present which is cheapest means of generating power                           

A. thermal power
B. nuclear power
C. hydroelectric power
D. electric power
Answer» C. hydroelectric power
271.

Pen stocks are made up of                           

A. steel
B. cast iron
C. mild steel
D. wrought iron
Answer» A. steel
272.

                        is an inward radial flow reaction turbine?

A. pelton turbine
B. kaplan turbine
C. francis turbine
D. propeller turbine
Answer» C. francis turbine
273.

                             is a axial flow reaction turbines, if vanes are fixed to hub of turbine

A. propeller turbine
B. francis turbine
C. kaplan turbine
D. pelton turbine
Answer» A. propeller turbine
274.

Francis and Kaplan turbines are known as

A. impulse turbine
B. reaction turbine
C. axial flow turbine
D. mixed flow turbine
Answer» B. reaction turbine
275.

Specific speed of reaction turbine is between?

A. 5 and 50
B. 10 and 100
C. 100 and 150
D. 150 and 300
Answer» B. 10 and 100
276.

Draft tube is also called               

A. straight divergent tube
B. simple elbow tube
C. thermal tube
D. elbow tube with varying cross section
Answer» A. straight divergent tube
277.

A draft tube helps in converting kinetic energy into                 

A. electrical work
B. mechanical work
C. chemical work
D. thermal work
Answer» B. mechanical work
278.

Most common application of the draft tube is              

A. rotor
B. motor
C. pump
D. filter
Answer» C. pump
279.

Draft tube consists of conical diffuser with angles of             

A. 10 deg
B. 20 deg
C. 30 deg
D. 40 deg
Answer» A. 10 deg
280.

Turbine that consists of draft tubes is called as                     

A. impulse turbine
B. curtis turbine
C. rateau turbine
D. reaction turbine
Answer» D. reaction turbine
281.

The exit diameter for a simple elbow draft tube should be                 

A. large
B. small
C. very small
D. same
Answer» A. large
282.

The other name for elbow with varying cross section tube is called           

A. pressure tube
B. bent draft tube
C. velocity tube
D. sink tube
Answer» B. bent draft tube
283.

What is the efficiency of the simple elbow type draft tube?

A. 10
B. 30
C. 60
D. 90
Answer» C. 60
284.

In nozzle governing, the flow rate of steam is regulated by                    

A. nozzles
B. pumping
C. drafting
D. intercooling
Answer» A. nozzles
285.

The flow rate of steam is controlled by regulating the                    

A. steam
B. pressure
C. temperature
D. speed
Answer» B. pressure
286.

What is the purpose of a steam turbine governing?

A. controls speed
B. controls flow rate
C. controls volume
D. controls discharge
Answer» B. controls flow rate
287.

When bypass valve is opened to                

A. increase pressure
B. increase unit speed
C. increase unit power
D. increase the amount of fresh steam
Answer» D. increase the amount of fresh steam
288.

With the increase in load, Energy in the turbine                  

A. decreases
B. increases
C. remains same
D. independent
Answer» A. decreases
289.

When the mechanical speed of the shaft increases beyond 110 percent, we use

A. throttle governing
B. steam governing
C. nozzle governing
D. emergency governing
Answer» D. emergency governing
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