Question

Final answer only ;

Water (10 C) flows with a speed of (V=1.5 m/s) through a horizontal plastic pipe of diameter (D=0.0622 m). The length of the pipe is (L= 30 m). The friction factor is equal to

a. f = 0.015

b. f = 0.192

c. f = 0.210

d. f = 0.018

The laminar boundary layer occurs

a. Smooth flow

b. Rough flow

c. Uniform flow

d. Random flow

A flow of water passing over a smooth thin flat plate long and wide at a velocity of . Assuming that the boundary layer is laminar at first and then becomes turbulent. Given The distance of the laminar boundary layer downstream of the leading edge is equal to

a. 0.22 m.

b. 0.0022 m

c. 2.22 m

d. None of these

For a rectangular channel of length =10m and its hydraulic radius = 3. The value of the width of the rectangular channel is equal to

a. y = 10

b. y = 4

c. y = 15

d. y = 2

The region of a flow in a pipe where the velocity distribution is variable is called

a. Developing region

b. Laminar flow region

c. Turbulent flow region

d. Developed flow region

What are the reasons for minor head loses in a pipe?

a. Friction

b. Heat

c. Valves and bends

d. Temperature

For a streamlined body to achieve low drag coefficient, the boundary layer must

a. Flow over the body

b. Be attached to the body

c. Move away from the body

d. Move parallel to the body

For a flow between a stationary and moving plates. If the shear stress at the moving plate is 200 N/m2. The shear stress at the center between the plates is

a. Zero.

b. 200 N/m2

c. 100 N/m2

d. None of these

Which among the following is an assumption of Hagen-Poiseuille equation?

a. Fluid is compressible

b. Fluid is uniform

c. Fluid is laminar

d. Fluid is turbulent

Darcy- Weisbach equation gives relation between

a. Pressure and temperature

b. Mass, volume and pressure

c. Head loss and pressure loss

d. Pressure loss only Question

Which among the following does not depend on the friction factor?

a. Pipe diameter

b. Fluid density

c. Viscosity

d.Gravity

Which of the following are features of a laminar boundary layer?

a. Flow is smooth

b. An increased boundary layer thickness correlate with decreased shear stress

c. An increased boundary layer thickness correlate with increased shear stress

d. A+B.

For any system considered, which of the following statements is correct?

a. Two pumps should be connected in series to increase the flow rate.

b. Two pumps should be connected in series to increase the pump head.

c. Two pumps should be connected in parallel to increase the flow rate.

d. B+C

What are the equations used to find the power of the pump used to pump water from a lower tank to an upper tank

a. Energy and power of the pump equations

b. Energy, continuity, and power of the pump equations

c. Energy, Darcy-Weisbeck, continuity, and power of the pump equations

d. All of these

The Hydraulic radius of a equilateral triangular channel of length is equal to

a. h/6L

b. hL/6

c. h/6

d. L/6h

The friction factor (f) in Moody’s diagram for a turbulent flow is only a function of

a. f (Re, Ks/D) only

b. f (Re, hf) only

c. f (Re, Ks/D, hf) only

d. None of these.

Case (A): The car speed is 5 km/hr Case (B): The car speed is 10 km/hr Assuming the same car in both cases

a. Power in case (B) = power in case (A).

b. Power in case (B) = 2 x power in case (A).

c. Power in case (B) = 4 x power in case (A).

d. Power in case (B) = 8 x power in case (A).

Answer 1