In order to avoid cavitation in centrifugal pumps

In centrifugal pumps, cavitation occurs, when pressure of the impeller eye or vane becomes

A

Less than atmospheric pressure

B

More than liquid vapor pressure

C

Less than liquid vapor pressure

D

More than atmospheric pressure

Probability of cavitation occuring becomes very high, when the local __________ resulting in water bubbles formation, which on rupture cause cavitation

A

Pressure falls below the vapour pressure

B

Pressure becomes very high

C

Temperature becomes low

D

All of the above

Cavitation in a pump creates so many undesirable effects. Out of the following, which is not an undesirable effect created by cavitation?

A

Decrease in effect

B

Increase in thrust

C

Develops noise

D

Develops high pressure

2 large and 1 small pumps can fill a water tank in 4 hours. 1 large and 3 small pumps can also fill the same water tank in 4 hours . How many hours will it take for 3 large 4 small pumps to fill the tank?

A

2 hours

B

2.5 hours

C

3 hours

D

3.5 hours

2 large and 1 small pumps can fill a water tank in 4 hours. One large and 3 small pumps can also fill the same water tank in 4 hours. how many hours will it take for 3 large and 4 small pumps to fill the tank?

A

2 hours

B

2.5 hours

C

3 hours

D

3.5 hours

The cost of manufacturing x water pumps is Tk.9000+400x. The amount received by selling these x water pumps is Tk. 500x. What is the least number of water pumps that must be manufactured and sold so that that the amount recieved is at least equal to the manufacturing cost ?

A

50

B

60

C

90

D

100

Reciprocating pumps compared to centrifugal pumps

A

Deliver liquid at uniform pressure

B

Can handle slurries more efficiently

C

Are not subject to air binding

D

Can be operated with delivery valve closed

Reciprocating pumps are no more to be seen in industrial applications (in comparison to centrifugal pumps) because of

A

High initial and maintenance cost

B

Lower discharge

C

Lower speed of operation

D

Necessity of air vessel

Reciprocating pumps are not able to compete with the centrifugal pump for industrial use, mainly because these pumps have

A

Very low speeds

B

Smaller discharge

C

Higher capital &maintenance cost

D

High vibrations

Centrifugal pumps as compared to reciprocating pumps

A

Run at a lower speed for the same discharge

B

Do not need priming

C

Deliver fluid with pulsating/fluctuating discharge

D

Can be run with discharge line valve closed for a short interval

In order to avoid cavitation in centrifugal pumps

Related Questions