Engineering Questions with Answers - Multiple Choice Questions
Mechanical Operations MCQ’s – Draft Tubes
1 - Question
How does the return flow to an impeller approaches the impeller?
a) From above
b) From below
c) From center
d) From all directions
View Answer
Answer: d
Explanation: The return flow to an impeller of any type approaches the impeller from all directions because it is not under the control of solid surfaces.
2 - Question
Impeller mixers should always have draft tubes.
a) True
b) False
View Answer
Answer: b
Explanation: In most cases of impeller mixer it is not a limitation but when the direction of flow and the suction to the impeller are to be controlled, draft tubes are used.
3 - Question
Draft tubes help to control ________________
a) Only the direction of flow
b) Only the suction to the impeller
c) The direction of flow and suction
d) Neither direction of flow nor suction
View Answer
Answer: c
Explanation: The purpose of using draft tubes is to control the direction of flow and the suction to the impeller. It is not a limitation to the use of impeller in most cases.
4 - Question
In a propeller, where are the draft tubes mounted?
a) Immediately above the impeller
b) Immediately below the impeller
c) Around the impeller
d) On the impeller
View Answer
Answer: c
Explanation: Draft tubes for propeller are mounted around the impeller, and those for turbines are mounted immediately around the impeller.
5 - Question
In a turbine, where are the draft tubes mounted?
a) Immediately above the impeller
b) Immediately below the impeller
c) Around the impeller
d) On the impeller
View Answer
Answer: a
Explanation: Draft tubes for propeller are mounted around the impeller, and those for turbines are mounted immediately above the impeller.
6 - Question
Using draft tubes is a limitation?
a) True
b) False
View Answer
Answer: b
Explanation: It is not a limitation to the use of impeller in most cases. The purpose of using draft tubes is to control the direction of flow and the suction to the impeller.
7 - Question
Shown figure illustrates _______
a) Turbine
b) Propeller
c) Baffleless tank
d) Agitation vessel
View Answer
Answer: b
Explanation: Draft tubes for propeller are mounted around the impeller, and those for turbines are mounted immediately above the impeller. As clearly visible in the image the draft tubes are around the impeller hence it is a propeller.
8 - Question
Shown figure illustrates _______
a) Turbine
b) Propeller
c) Baffleless tank
d) Agitation vessel
View Answer
Answer: a
Explanation: Draft tubes for propeller are mounted around the impeller, and those for turbines are mounted immediately above the impeller. As clearly visible in the image the draft tubes are immediately above the impeller hence it is a turbine.
9 - Question
Use of draft tubes _________________
a) Add to the fluid friction
b) Have no effect on fluid friction
c) Reduce fluid friction
d) Depend on the type of Fluid
View Answer
Answer: a
Explanation: Draft tubes add to the fluid friction in the system, and for a given power input, they reduce the rate of flow, so they are not used unless required.
10 - Question
Use of draft tubes _________________
a) Increase the rate of fluid flow
b) Decrease the rate of fluid flow
c) Have no impact on the rate of flow
d) Depends on the type of fluid
View Answer
Answer: b
Explanation: Draft tubes add to the fluid friction in the system, and for a given power input, they reduce the rate of flow, so they are not used unless required.