MOMENTRA

The viscosity of a gas

a. decreases with increase in temperature

b. increases with increase in temperature

c. is independent of temperature

d. is independent of pressure for very high pressure intensities

b. increases with increase in temperature

The dimensionless number that characterizes the flows of fluid

in a conduit.

a. Nusselt number c. Grashof number

b. Peclet number d. Reynolds number

d. Reynolds number

Turbulent flow generally occurs for cases involving

a. viscous fluid

b. very narrow passages for capillary tube

c. very slow motions

d. none of these

d. none of these

When a fluid flows through a reducer in a piping system, the

velocity at the outlet end is the velocity at the inlet.

a. less than c. the same as

b. more than d. one-half

b. more than

For pipes that must be broken at intervals for maintenance,

the connector used should be a/an

a. union c. tee

b. reducer d. elbow

a. union

Which valve is used accurately to regulate the flow of liquids

and gases at low flow rates?

a. needle valve c. ball valve

b. check valve d. globe valve

a. needle valve

Which of the following is not true?

a. A pump will operate safely if its NPSH is greater than zero.

b. Fans and blowers are used to transport gases.

c. Pumps and blowers increase the mechanical energy of the

fluid.

d. The power loss due to friction in a venturi meter is greater

than in an orifice meter.

d. The power loss due to friction in a venturi meter is greater

than in an orifice meter.

Which statement is not true?

a. Potential flow is a flow of compressible fluids with no shear.

b. Rotameters are variable-head meters.

c. There are 8 schedule numbers in used for standard pipes.

d. Roughness has no appreciable effect on the friction factor

when flow is laminar

c. There are 8 schedule numbers in used for standard pipes.

For an ideal fluid flow, the Reynolds number is
a. 2100
b. 100
c. Zero
d. infinity

d. infinity

The dimension of dynamic viscosity is
a. ML^-1 T^-1
b. L² T^-1
c. LT²
d. ML^-1T^-2

a. ML^-1 T^-1

Dimension of surface tension is (where, F=force, L-length)
a. FL^-1
b. F¹ L
c. F L^-2

d. F² L

a. FL^-1

An ideal fluid is
A. frictionless and incompressible
b one, which obeys Newton’s Law of viscosity
c. Highly viscous

d. none of these

A. frictionless and incompressible

Power number is the ratio of

a. drag stress to inertial stress

b. inertial stress to drag stress

c. inertial stress to gravitational stress

d. gravitational stress to drag stress

a. drag stress to inertial stress

Weber number is the ratio of internal force to _______ force
a. surface tension

b, gravity

c. viscous

d. elastic

a. surface tension

Viscosity of water at 40 deg C lies in the range of
A. 1×10^-3 to 2 × 10^{-3 .}kg/m-s
B. 0.5×10^-3 to 2 × 10^{-3 .}kg/m-s
C. 1 to 2 ^.kg/m-s
D. 0.5 to 1 ^.kg/m-s

B. 0.5×10^-3 to 2 × 10^{-3 .}kg/m-s

All pipes of a particular nominal size have the same

a. inside diameter

b. outside diameter

c. thickness

d. none of these

b. outside diameter

Pipes having diameter 14 inches or more are designated by their

a. outside diameter

b. inside diameter

c. schedule number

d. none of these

a. outside diameter

Lower BWG means ______ of the tube
a. lower thickness

b. lower cross-section

c. outer diameter

d. inner diameter

b. lower cross-section

A fluid apparent viscosity increases with shear rate is termed as the ________ fluid

a. Newtonian

b. viscous

c. dilatant

d. non-viscous

c. dilatant

Quicksand is an example of a _________ fluid

a. bingham plastic

b. dilatent

c. newtonion

d. pseudoplastic

b. dilatent

If blausius or Darcey friction factor is f₁ then the fanning friction factor is equal to

a. f₁/4
b. 4f₂

c. 2f₁

d. f₁/2

a. f₁/4

The general relationship between speed N, Head H, power P and discharge Q for a centrifugal pump is
a. Q=N : H = N² : P = N³
b. Q=N² : H = N³ : P = N
c. Q=N : H = N³ : P = N²
d. Q=N³ : H = N² : P = N²

a. Q=N : H = N² : P = N³

A centrifugal pump has the following specifications:
Power = 4 H.P.; Speed = 800 rpm
Head = 8 metres
Flow = 1000 litres/minutes.
If its speed is halved, then the new head will be __________litres/minute

A. 500

B. 200

C. 1000

D. 750

A. 500

Hydraulic radius of 6×12 cross-section is ________ inches

a. 2

b. 0.5

c. 1.5

d. none of these

a. 2