# Previous Years’ Fluid Mechanics Objective Questions

## Fluid Mechanics Objective Questions

These Fluid Mechanics Objective Questions are very important for the competitive exams like SSC JE, RRB, GATE, ISRO, DRDO, and all other competitive exams.

All these Fluid Mechanics Objective Questions are from the previous years’ papers of one of the exams mentioned before.

1. Laminar developed flow at an average velocity of 5 m/s occurs in a pipe of a 10 cm radius. The velocity at 5 cm radius is?

A. 6.5 m/s

B. 7 m/s

C. 7.5 m/s

D. 8m/s

Using the Formula

U = 2Uavg. [1 – (r/R)² ]

2. Flow separation is caused by –

C. reduction of pressure to the local vapor pressure

D. thinning of boundary layer thickness to zero

3. A centrifugal pump is started with its delivery valve kept –

A. fully closed

B. fully open

C. partially open

D. 50% open

4. Ir-rotational flow occurs when?

A. there is no net rotation of the fluid element about its mass center

B. streamlines are curved

C. fluid element does not undergo any change in size or shape

D. flow takes place in a duct of a uniform cross-section at a constant mass flow rate

5. Which of the following forces act on a fluid at rest?

1. Gravity force
2. Hydrostatic force
3. Surface tension
4. Viscous force

A. All of these

B. 1 and 2

C. 1, 2 and 4

D. 1, 2 and 3