Midterm

Question 1

In turbulent pipe liquid flow, zero velocity at the tube wall and a parabolic velocity distribution.

Answer 1

False

Question 2

Pipe flows with Re number less than 6000 are inherently laminar

Answer 2

false

Question 3

Pipe flows with Re number more than 4000 are mostly turbulent but it might be laminar in few cases

Answer 3

True

Question 4

For the same liquid and pipe diameter, increasing flow rate leads to an increase in the Re number

Answer 4

True

Question 5

For the same liquid and flow rate , increasing the pipe diameter leads to an decrease in the Re number

Answer 5

False

Question 6

Drop in pressure of liquid flow in coarse pipe is higher than the drop of pressure in smooth pipe

Answer 6

True

Question 7

In a water flowing pipeline, if the diameter of a pipe is reduced, the pressure drop in the line per unit length will decrease

Answer 7

False

Question 8

friction factor in a liquid flow in a pipe decreases with decreasing Re number

Answer 8

false

Question 9

For the same pipe and liquid , pressure drop decreases with the increase in the flow rate

Answer 9

false

Question 10

Based on Moodys’ diagram shown below, Friction factor in a liquid flow in a pipe increases with decreasing relative roughness (D/e)

Answer 10

false

Question 11

Based on Moody’s diagram shown below, Friction factor in a fully laminar liquid flow is:

Answer 11

inversely proportional to Re

Question 12

The dynamic viscosity is calculated by measuring the terminal velocity (v) of a ball falling through a fluid

Answer 12

True

Question 13

If a gravity acceleration is 9.822 m/s2 at standard sea level, then, the weight of 1kg-force is equal to 1 kg-mass

Answer 13

True

Question 14

Hydrometer sinks deeper in liquid as the SG of the liquid increases

Answer 14

False

Question 15

As fluid temperature increases, the density of the fluid increases.

Answer 15

False

Question 16

Liquid water is assumed to be an incompressible fluid to simplify calculations.

Answer 16

True

Question 17

Oil is slightly compressible fluid; therefore, it can not be considered as ideal fluid.

Answer 17

False

Question 18

Small ceramic ball fall in oil at a lower velocity than falling a large ceramic ball.

Answer 18

True

Question 19

Hydrostatic pressure is the pressure that is exerted by a liquid at equilibrium at a given point within the liquid, due to the force of gravity; it depends on density of liquid, gravity acceleration, and the vertical depth form the surface of the liquid (P =pgh).

Answer 19

True

Question 20

Terminal velocity of falling ball in oil decreases with increasing oil temperature.

Answer 20

False

Question 21

The direction of pressure is always perpendicular to surface area of a body emerged inside fluids.

Answer 21

True

Question 22

The peizometric head is what is measured with the manometer board on the apparatus for lab 3 experiment

Answer 22

True

Question 23

The energy loss for the rotameter decreases with increasing the liquid flow rate

Answer 23

True

Question 24

Venturi flowmeter can’t be used in pipes having small diameter

Answer 24

True

Question 25

The energy loss associated with the orifice meter is small.

Answer 25

False

Question 26

The energy loss for the rotameter is seen to be approximately constant irrespective of flow rate

Answer 26

True

Question 27

The discharge coefficient of the orifice flow meter is low.

Answer 27

True

Question 28

The venturi tube is suitable for clean liquid but not for dirty and viscous liquid.

Answer 28

False

Question 29

From the following identify which flowmeter requires to be mounted vertically?

Answer 29

Rotameter

Question 30

Small ceramic ball fall in oil at a higher velocity than falling a large ceramic ball

Answer 30

False

Question 31

If the temperature of the liquid decreases, its viscosity will increase causing the balls to
travel through the liquid faster.

Answer 31

False

Question 32

Based on Moody’s diagram shown below, friction factor in a transition liquid flow in a pipe decreases with decreasing Reynolds.

Answer 32

False

Question 33

Based on Moody’s diagram shown below, Friction factor in a liquid flow in a pipe increases with increasing relative roughness

Answer 33

True

Question 34

Friction Losses in Pipes is constant for fully turbulent flow.

Answer 34

True

Question 35

For laminar flow in a horizontal pipe, the friction factor decreases with increasing Reynolds number and independents on surface roughness.

Answer 35

False

Question 36

Slow fluid flows are dominated by viscous forces.

Answer 36

True

Question 37

In the Venturi flowmeter, viscosity effect is low

Answer 37

False

Question 38

In the Orifice flowmeter, viscosity effect is low

Answer 38

False

Question 39

The energy loss for the rotameter increases with increasing the liquid flow rate.

Answer 39

False