For laminar flow in a pipe of circular cross-section, the Darcy’s friction factor f is________________?

A. directly proportional to Reynolds number and independent of pipe wall roughness
B. directly proportional to pipe wall roughness and independent of Reynolds number
C. inversely proportional to Reynolds number and indpendent of pipe wall roughness
D. inversely proportional to Reynolds number and directly proportional to pipe wall roughness

Related Mcqs:

For laminar flow in circular pipes, the Darcy’s friction factor f is equal to_________________?
A. 16/Re
B. 32/ Re
C. 64/ Re
D. none of the above where R,, is Reynolds number
If velocity is zero over l/3rd of a cross-section and is uniform over remaining 2/3rd of the cross-section, then the correction factor for kinetic energy is__________________?
A. 4/3
B. 3/2
C. 9/4
D. 27/8
The velocity distribution for laminar flow through a circular tube__________________?
A. is constant over the cross-section
B. varies linearly from zero at walls to maximum at centre
C. varies parabolically with maximum at the centre
D. none of the above
The ratio of average velocity to maximum velocity for steady laminar flow in circular pipes is_______________?
A. 1/2
B. 2/3
C. 3/2
D. 2
A fluid of kinematic viscosity 0.4 cm2/sec flows through a 8 cm diameter pipe. The maximum velocity for laminar flow will be__________________?
A. less than 1 m/sec
B. 1 m/sec
C. 1.5 m/sec
D. 2 m/sec
The horse power transmitted through a pipe is maximum when the ratio of loss of head due to friction and total head supplied is________________?
A. 1/3
B. 1/4
C. 1/2
D. 2/3
The depth ‘d’ below the free surface at which the point velocity is equal to the average velocity of flow for a uniform laminar flow with a free surface, will be_________________?
A. 0.423 D
B. 0.577 D
C. 0.223 D
D. 0.707 D
where D is the depth of flow
The distance y from pipe boundary, at which the point velocity is equal to average velocity for turbulent flow, is________________?
A. 0.223 R
B. 0.423 R
C. 0.577 R
D. 0.707 R
where R is radius of pipe
Flow at constant rate through a tapering pipe is________________?
1. steady flow
2. uniform flow
3. unsteady flow
4. non-uniform flow
The correct answer is?
A. (1) and (2)
B. (1)and(iv)
C. (2) and (3)
D. (2) and (4)
When the velocity distribution is uniform over the cross-section, the correction factor for momentum is__________________?
A. 0
B. 1
C. 4/3
D. 2