Power Engineering - 4B1, 4B2, 4B7
Practice Questions With Complete
Solutions
A pump is capable of suction lift due to
a. its ability to convert kinetic energy into potential energy
b. the speed at which it operates
c. its input power
d. its size
e. atmospheric pressure
Centrifugal pumps do not develop good suction lift because
a. atmospheric pressure is usually too low
b. the pumped medium relative density is too high
c. their internal component clearances are too high
d. the speed is too low
e. they favour pressure rather than volume
It is generally accurate to say that
a. 9.8 kPa pressure results from every metre of water depth or height
b. a water height or depth of 10.34 metres results in 1 kPa
c. 1 kPa will result from a water head of 9.8 metres
d. 10.21 kPa will result from 1 metre of static water head
e. atmospheric pressure has no bearing on static water head
Preferably, dynamic pumps should be located
a. directly under the liquid source when suction lift is involved
b. above the liquid source when suction head is involved
c. above the liquid source when suction lift is involved
d. at the liquid source level when suction lift is involved
e. below the liquid source when suction head is involved
The vertical distance from the liquid surface up to the pump centre-line plus the
vertical distance from the pump centre-line up to the surface of the liquid in the
,discharge tank is
a. static discharge head
b. static suction head
c. suction lift
d. total discharge head
e. total static head
The difference between static suction head and static discharge head is
a. total static head
b. static discharge head
c. static suction head
d. equivalent head
e. dynamic head
When a pump discharges into a vessel operating at 300 kPa, the 300 kPa is
referred to as
a. dynamic head
b. equivalent head
c. discharge head
d. friction head
e. total static head
The total static head of a pump
a. is the capacity of the pump
b. is the difference between the static suction head and the static discharge head
c. is the discharge pressure in metres
d. is all the parts of the pump casing
e. is the discharge head of the pump
When a reciprocating pump discharges while its piston or plunger moves in only
one direction, it is termed a
a. positive displacement unit
b. single acting unit
c. dynamic unit
d. double acting unit
e. duplex unit
Centrifugal pumps convert rotating mechanical energy into kinetic energy then
a. discharge the kinetic energy
b. back to mechanical energy
,c. absorb the energy
d. into potential energy in the form of pressure
e. into centrifugal force
A hot water heating system circulator should
a. be directly coupled
b. have its own vibration-free base
c. be very quiet in operation
d. develop an extremely high differential pressure
e. not run continuously
The capacity of a centrifugal pump
a. varies with discharge pressure
b. can be altered by speed variation only
c. indicates that the unit is a positive displacement type
d. should be varied by suction valve manipulation
e. is fixed and can only be altered by changing the impeller
Centrifugal pump power requirements are decreased when
a. discharge pressure is decreased
b. the litres moved per minute is decreased
c. the casing pressure drops
d. the discharge velocity is high
e. the discharge head is at minimum
A rotary pump
a. is a variety of dynamic unit
b. never has discharge pulsations
c. should be equipped with a relief valve
d. has the highest capacity of any pump
e. never requires cylinder lubrication
When starting-up a rotary pump you must be sure that the
a. discharge valve is closed
b. discharge valve is open
c. pump is filled with air
d. pump is at the correct temperature
e. pump suction valve is closed
Rotary pumps:
1. are high pressure pumps
, 2. must be primed
3. use mechanical seals
4. are positive displacement pumps
a. 1, 2
b. 2, 3
c. 1, 4
d. 1, 3, 4
e. 1, 2, 3, 4
A double-acting pump
a. has two pistons on the pump end
b. will always be driven by the steam pistons
c. has two pistons on the driver end
d. will have two slide valves
e. is a positive displacement pump
A volute type pump
a. is a positive displacement pump
b. has a progressively expanding spiral casing
c. reduces the velocity in the discharge nozzle
d. is more costly than diffuser pumps
e. is a regenerative type pump
A diffuser pump:
1. has stationary guide vanes surrounding the impeller
2. has a higher efficiency than a volute type
3. has high suction lift
4. does not have to be primed
a. 1
b. 3
c. 2, 3
d. 1, 2
e. 4
Turbine pumps:
1. are high capacity pumps
2. are high pressure pumps
3. has the liquid gain energy in a number of impulses
a. 1
b. 1, 2
c. 2, 3
Practice Questions With Complete
Solutions
A pump is capable of suction lift due to
a. its ability to convert kinetic energy into potential energy
b. the speed at which it operates
c. its input power
d. its size
e. atmospheric pressure
Centrifugal pumps do not develop good suction lift because
a. atmospheric pressure is usually too low
b. the pumped medium relative density is too high
c. their internal component clearances are too high
d. the speed is too low
e. they favour pressure rather than volume
It is generally accurate to say that
a. 9.8 kPa pressure results from every metre of water depth or height
b. a water height or depth of 10.34 metres results in 1 kPa
c. 1 kPa will result from a water head of 9.8 metres
d. 10.21 kPa will result from 1 metre of static water head
e. atmospheric pressure has no bearing on static water head
Preferably, dynamic pumps should be located
a. directly under the liquid source when suction lift is involved
b. above the liquid source when suction head is involved
c. above the liquid source when suction lift is involved
d. at the liquid source level when suction lift is involved
e. below the liquid source when suction head is involved
The vertical distance from the liquid surface up to the pump centre-line plus the
vertical distance from the pump centre-line up to the surface of the liquid in the
,discharge tank is
a. static discharge head
b. static suction head
c. suction lift
d. total discharge head
e. total static head
The difference between static suction head and static discharge head is
a. total static head
b. static discharge head
c. static suction head
d. equivalent head
e. dynamic head
When a pump discharges into a vessel operating at 300 kPa, the 300 kPa is
referred to as
a. dynamic head
b. equivalent head
c. discharge head
d. friction head
e. total static head
The total static head of a pump
a. is the capacity of the pump
b. is the difference between the static suction head and the static discharge head
c. is the discharge pressure in metres
d. is all the parts of the pump casing
e. is the discharge head of the pump
When a reciprocating pump discharges while its piston or plunger moves in only
one direction, it is termed a
a. positive displacement unit
b. single acting unit
c. dynamic unit
d. double acting unit
e. duplex unit
Centrifugal pumps convert rotating mechanical energy into kinetic energy then
a. discharge the kinetic energy
b. back to mechanical energy
,c. absorb the energy
d. into potential energy in the form of pressure
e. into centrifugal force
A hot water heating system circulator should
a. be directly coupled
b. have its own vibration-free base
c. be very quiet in operation
d. develop an extremely high differential pressure
e. not run continuously
The capacity of a centrifugal pump
a. varies with discharge pressure
b. can be altered by speed variation only
c. indicates that the unit is a positive displacement type
d. should be varied by suction valve manipulation
e. is fixed and can only be altered by changing the impeller
Centrifugal pump power requirements are decreased when
a. discharge pressure is decreased
b. the litres moved per minute is decreased
c. the casing pressure drops
d. the discharge velocity is high
e. the discharge head is at minimum
A rotary pump
a. is a variety of dynamic unit
b. never has discharge pulsations
c. should be equipped with a relief valve
d. has the highest capacity of any pump
e. never requires cylinder lubrication
When starting-up a rotary pump you must be sure that the
a. discharge valve is closed
b. discharge valve is open
c. pump is filled with air
d. pump is at the correct temperature
e. pump suction valve is closed
Rotary pumps:
1. are high pressure pumps
, 2. must be primed
3. use mechanical seals
4. are positive displacement pumps
a. 1, 2
b. 2, 3
c. 1, 4
d. 1, 3, 4
e. 1, 2, 3, 4
A double-acting pump
a. has two pistons on the pump end
b. will always be driven by the steam pistons
c. has two pistons on the driver end
d. will have two slide valves
e. is a positive displacement pump
A volute type pump
a. is a positive displacement pump
b. has a progressively expanding spiral casing
c. reduces the velocity in the discharge nozzle
d. is more costly than diffuser pumps
e. is a regenerative type pump
A diffuser pump:
1. has stationary guide vanes surrounding the impeller
2. has a higher efficiency than a volute type
3. has high suction lift
4. does not have to be primed
a. 1
b. 3
c. 2, 3
d. 1, 2
e. 4
Turbine pumps:
1. are high capacity pumps
2. are high pressure pumps
3. has the liquid gain energy in a number of impulses
a. 1
b. 1, 2
c. 2, 3
