Waste Water Engineering MCQ - Construction & Planning of Sewer System Part-2

1. An apparatus for raising, driving or compressing fluids or gases is called _________
a) Piston
b) Pump
c) Compressor
d) Force drive

Answer: b
Explanation: A pump is a device used to transfer or force the liquid or gas against gravity. There are different types of pumps based on the requirements and the pumps are designed for different loads.

2. ________ pumps produce a head and a flow by increasing the velocity of the liquid with the help of the rotating vane impeller.
a) Displacement pumps
b) Positive pumps
c) Centrifugal pumps
d) Rotating pumps

Answer: c
Explanation: Centrifugal pumps produce a head and a flow by increasing the velocity of the liquid with the help of the rotating vane impeller. Centrifugal pumps include radial, axial and mixed flow units.

3. What are the pumps that operate by alternately filling a cavity and then displacing a given volume of liquid called?
a) Centrifugal pump
b) Rotating pump
c) Positive displacement pump
d) Roto-dynamic pump

Answer: c
Explanation: A positive displacement pump alternately fills a cavity and then displaces a given volume of liquid. For each cycle, this pump delivers a constant volume of liquid independent of discharge pressure or head.

4. The two types of pumps behave very differently regarding pressure head and flow rate.
a) True
b) False

Answer: a
Explanation: There are two types of basic pumps. One is the centrifugal pump and the other one is positive displacement pump. Centrifugal pump is also called as a roto-dynamic pump. These two pumps behave very differently with respect to flow rates and pressure head.

5. A steam pump is a type of centrifugal pump.
a) True
b) False

Answer: b
Explanation: There are different types of centrifugal pumps such as end suction pumps, in-line pumps, axial-flow pumps, regenerative pumps, etc. Steam pump is a type of positive displacement pump.

6. In a centrifugal pump, the flow is _______ when the viscosity is increased.
a) Reduced
b) Increased
c) Greater
d) Same

Answer: a
Explanation: In a centrifugal pump, the flow is reduced when the viscosity is increased. This is because the viscosity of any fluid restricts its capacity to flow easily. On thickening the solution or liquid, the flow is reduced.

7. What are the pumps with one or more impellers called?
a) ANSI process pumps
b) API process pumps
c) Centrifugal pumps
d) Positive displacement pumps

Answer: c
Explanation: The general name for pumps with one or more impellers is called centrifugal pumps. Many types and configurations of centrifugal pumps are used for different applications.

8. Why are booster pumps used?
a) Higher flow
b) Boost pressure
c) Chop solids
d) Maintain flow

Answer: b
Explanation: Booster pumps are used to further boost the pressure in a system. It may be in-line circulator, horizontal split case, or vertical turbine in a can type of pump. Chopper Pumps are designed to chop up solids and stringy material as it pumps.

9. Why are cryogenic pumps used?
a) Boost pressure
b) Handle low temperature liquids
c) Handle high temperature liquids
d) Pump small quantities of liquids

Answer: b
Explanation: Cryogenic pumps are used to handle very low temperature liquids. Booster pumps are used to further boost the pressure in a system. Drum pumps are used to pump out small quantities of liquid of out of drums and carboys.

10. End suction pumps are the common type of _________ pumps.
a) Drum pumps
b) Centrifugal pumps
c) Positive displacement pumps
d) Grinder pumps

Answer: b
Explanation: End suction pumps are the common type of centrifugal pump. It has a horizontal shaft with an overhung impeller. The flow goes in the end of the casing, and out the top.