Environmental Engineering Multiple Choice Questions on “Well Pump”.
1. Which of the following pump is not an example of well pump?
a) Hand pumps
b) Steam engine pumps
c) Jet pumps
d) Centrifugal pumps
Answer: b
Clarification: The types of pumps that are used for lifting water from wells are Hand pumps, Reciprocating pumps, Centrifugal pumps, Air lift pumps and Jet pumps.
2. Which type of pump is specifically used for shallow wells?
a) Hand pump
b) Reciprocating pump
c) Jet pump
d) Centrifugal pump
Answer: a
Clarification: Hand pumps are used specifically for shallow wells, whereas Reciprocating pumps are used for deep wells.
3. How many types of hand pumps are used?
a) 1
b) 2
c) 3
d) 4
Answer: b
Clarification: There are two types of hand pumps- Pitcher pump and Force pump. A Pitcher pump consists of a cylinder in which a plunger moves up and down.
4. The maximum number of impellers in a centrifugal well pump is _____________
a) 20
b) 30
c) 40
d) 50
Answer: a
Clarification: The maximum number of impellers in a centrifugal well pump is 20 and it depends on the head, mixed flow, propeller type with vanes and guide passages.
5. The diameter of turbine used in centrifugal well pump is _____________
a) 50cm
b) 64cm
c) 15cm
d) 100cm
Answer: c
Clarification: The diameter of turbine used in centrifugal well pump lies between 10 to 35cm and its length varies from 20 to 60cm.
6. _______ is provided at the entrance of suction pipe during centrifugal pump installation.
a) Delivery pipe
b) Foot valve
c) Strainer
d) Check valve
Answer: c
Clarification: Strainer is provided at the entrance of suction pipe during centrifugal pump installation to prevent the clogging otherwise it will damage the pump.
7. Which part of centrifugal well pumps act as a self priming device?
a) Delivery pipe
b) Foot valve
c) Strainer
d) Check valve
Answer: c
Clarification: When the pump is stopped, the foot valve prevents the water from leaving the pump. Therefore, it acts as a self priming device.
8. Which part of centrifugal well pumps prevents the back flow through the pump?
a) Delivery pipe
b) Foot valve
c) Strainer
d) Check valve
Answer: d
Clarification: Check valve is present at the entrance of the delivery pipe which prevents the back flow of water through the pump.
9. __________ is defined as the speed at which a pump will discharge a unit flow under a unit head at maximum efficiency.
a) Specific speed
b) Average speed
c) Maximum speed
d) Relative speed
Answer: a
Clarification: The speed at which the pump will discharge a unit flow under a unit head at maximum efficiency is called specific speed. It is denoted by NS.
10. The unit of specific speed is _____________
a) Metre/second
b) Metre/second2
c) Centimetre/second
d) Dimensionless
Answer: d
Clarification: Specific speed is a dimensionless quantity which is given by NS = NQ1/2 / H3/4.
11. The specific speed of the pump is 8000. What is the type of pump?
a) Reciprocating pump
b) Centrifugal pump
c) Mixed flow pump
d) Axial flow pump
Answer:d
Clarification: When the specific speed lies between 5000 to 10,000, the type of the pump is an axial flow pump.