Fluid Mechanics MCQs

631. Purpose of relief valve in a reciprocating pump is to

Protect the pump against developing excessive pressure

Facilitate unidirectional flow of liquid

Reduce the discharge pressure

Control the rate of discharge

✅ The correct answer is option A.

632. The capacity of a centrifugal pump Can be increased by increasing the

Impeller diameter or speed

Number of pumps and joining them in series

Number of pumps and joining them in parallel

All of the above

✅ The correct answer is option D.

633. In parallel pipe problems, the

Head loss is the same through each pipe

Discharge is the same through all the pipes

Total head loss is equal to the sum of the head losses through each pipe

None of these

✅ The correct answer is option A.

634. The pipe wall thickness is minimum for a pipe of given nominal size having schedule number

160

120

80

40

✅ The correct answer is option D.

635. The maximum delivery pressure of compressors can be upto __________ atmospheres.

10

100

250

1000

✅ The correct answer is option D.

636. Glass pipes can be joined by

Flanges

Welding

Soldering

Bell and spigot joint

✅ The correct answer is option D.

637. Which of the fluid forces are not considered in the Reynold’s equation of flow?

Viscous forces

Turbulent forces

Pressure forces

Compressibility forces

✅ The correct answer is option D.

638. Two dimensional stream function

Relates velocity and pressure

Is constant along a stream line

Is constant along an equipotential surface

None of these

✅ The correct answer is option B.

639. The equation relating friction factor to Reynold number, f-0.5 = 4 loge (NRe/√f)-0.4, is called the __________ equation.

Nikuradse

Von-Karman

Blausius

Colebrook

✅ The correct answer is option A.

640. Rotary vacuum pumps can reduce the absolute pressure to as low as __________ mm Hg.

1

0.1

0.01

0.001

✅ The correct answer is option C.