Momentra Flashcards
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 liquide:
B
The dimensionless number that characterizes the flows of fluid in a conduit.
a. Nusselt number
b. Peclet number
c. Grashof number
d. Reynolds number
D
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
For an ideal fluid flow, the Reynolds number is
a. 2100
b. 100
c. zero
d. infinity
D
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
b. more than
c. the same as
d. one-half
B
For pipes that must be broken at intervals for maintenance, the connector used should be a/an
a. union
b. reducer
c. tee
d. elbow
A
Which valve is used accurately to regulate the flow of liquids and gases at low flow rates?
a. needle valve
b. check valve
c. ball valve
d. globe valve
A
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
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
