Fluid Mechanics MCQs

Question 1

Working of a __________ pump characterises mixed flow.

Accepted Answer

Turbine

Answer

Piston

Answer

Diaphragm

Answer

None of these

Question 2

Which is the correct relationship for a centrifugal pump? (where, D = Impeller diameter, inches H = Head developed, ft of liquid pumped N = Speed of pump, rpm)

Accepted Answer

D = 1840 H0.5/N

Answer

D = 1840 N/H0.5

Answer

H = 1840 D0.5/N

Answer

D = 1840 H/N

Question 3

Purpose of air lift pump is to

Accepted Answer

Lift water from a well by using compressed air

Answer

Compress air

Answer

Lift compressed air

Answer

Lift air under negative pressure

Question 4

A pump operating under specific conditions delivers insufficient quantity of liquid. This may be set right by

Accepted Answer

Both B and C

Answer

Decreasing the size of the inlet pipe

Answer

Increasing the size of the inlet pipe

Answer

Lowering the pump position

Question 5

A pressure of 10 m head of water is equivalent to __________ kN/m2.

Accepted Answer

98

Answer

147

Answer

196

Answer

49

Question 6

Viscosity of water at 40°C lies in the range of

Accepted Answer

0.5 × 10-3 to 1 × 10-3 kg/m.s

Answer

1 × 10-3 to 2 × 10-3 kg/m.s

Answer

1 to 2 kg/m.s

Answer

0.5 to 1 kg/m.s

Question 7

Which of the following conditions must be satisfied for lift force to be developed?

Accepted Answer

Circulation around the body is essentially required

Answer

The body should be bluff body

Answer

The body should be stream lined

Answer

The main stream velocity must approach the velocity of sound in that fluid medium

Question 8

Pipes having diameter 14 inches or more are designated by their

Accepted Answer

Outside diameter

Answer

Inside diameter

Answer

Schedule number

Answer

None of these

Question 9

For flow past a flat plate, if x is the distance along the plate in the direction of flow, the boundary layer thickness is proportional to

Accepted Answer

$$\sqrt {	ext{x}} $$

Answer

$$\frac{1}{{\sqrt {	ext{x}} }}$$

Answer

x

Answer

$$\frac{1}{{	ext{x}}}$$