A. Where there is no velocity gradient
B. At higher temperatures
C. Only in Newtonian fluids
D. None of these
Related Mcqs:
- In isotropic turbulence, the _____________ are equal to each other?
A. Temporal velocity components
B. Mean square of velocity fluctuations in the three co-ordinate directions
C. Root mean square of velocity fluctuations in the three co-ordinate directions
D. None of these - In the complete turbulence zone (in rough pipes), the____________________?
A. Rough and smooth pipes have the same friction factor
B. Laminar film covers the roughness projections
C. Friction factor depends upon NRe only
D. Friction factor is independent of the relative roughness - In centrifugal pumps, cavitation occurs, when pressure of the impeller eye or vane becomes_______________?
A. Less than atmospheric pressure
B. More than liquid vapor pressure
C. Less than liquid vapor pressure
D. More than atmospheric pressure - Slugging occurs in a fluidised bed, if the bed is___________________?
A. Narrow
B. Deep
C. Both A. & B.
D. Neither A. nor B. - Cavitation occurs in a centrifugal pump when the suction pressure is________________?
A. Less than the vapour pressure of the liquid at that temperature
B. Greater than the vapour pressure of the liquid at that temperature
C. Equal to the vapour pressure
D. Equal to the developed head - Steady fluid flow occurs, when the derivative of flow variables satisfy the following condition.
A. ∂/∂s = 0
B. ∂/∂t = 0
C. ∂/∂s = constant
D. ∂/∂t = constant - Turbulent flow generally occurs for cases involving__________________?
A. Highly viscous fluid
B. Very narrow passages
C. Very slow motion
D. None of these - Steady flow occurs, when the__________________?
A. Conditions change steadily with time
B. Conditions are the same at the adjacent points at any instant
C. Conditions do not change with time at any point
D. Rate of the velocity change is constant - Boundary layer separation occurs when the____________________?
A. Pressure reaches a minimum
B. Cross-section of the channel is reduced
C. Valve is closed in a pipeline
D. Velocity of sound is reached - In open channel flow in a rectangular channel, the ratio between the critical depth and the initial depth, when a hydraulic jump occurs is_________________?
A. 0.5
B. 0.84
C. 1.84
D. 1.25
