Power Engineering - 4B9, 4B10 Practice Questions With
Complete Solutions
Which of the following devices has a de-clutching feature?
a. A variable speed motor control.
b. A fluid drive.
c. An outlet damper control.
d. A V-belt drive.
e. A variable inlet vane control.
b. A fluid drive.
The type of operation which stops the compressor when the
desired low temperature of the substance to be cooled is reached
and starts the compressor up again when the temperature rises to
a set level is called:
a. cylinder bypass operation
b. variable guide operation
c. intermittent operation
d. unloading operation
e. continuous operation with reduced output
c. intermittent operation
To prevent freezing of downstream equipment in a coil handling
a large amount of outdoor air, which of the following is
required?
,a. A preheat coil.
b. Two-Position damper motor.
c. A long coil length.
d. An oversized coil.
e. A vacuum breaker.
a. A preheat coil.
Steam coils:
a. Do not require a vacuum breaker.
b. Do not require air venting.
c. Should be installed with tubes in a vertical position to ensure
positive condensate drainage.
d. Are installed exactly the same as are glycol coils.
e. When installed in the horizontal position, do not have to be
pitched toward the return.
c. Should be installed with tubes in a vertical position to ensure
positive condensate drainage.
When all supply air duct is outside the conditioned space there is
a certain leakage. This leakage must be calculated how?
a. It must be added to the calculated room specific latent
humidity load.
b. It must be subtracted from the return air duct leakage.
c. It need not be considered in loss calculation.
d. It must be added to the calculated room sensible heat load.
e. It must be added to the return air duct leakage.
d. It must be added to the calculated room sensible heat load.
,The two general groups of fans are:
a. Centrifugal and axial flow.
b. Rotary positive displacement and centrifugal.
c. Reciprocating and axial flow.
d. Positive displacement and axial flow.
e. Reciprocating and centrifugal.
a. Centrifugal and axial flow.
This type of drive is normally used on small fan coil units to
heat or cool the perimeter areas of a building.
a. direct drive
b. variable inlet vane control
c. variable speed motor control
d. v-belt drive
e. fluid drive
a. direct drive
A typical stationary crankshaft seal consisting of a metallic
bellows soldered at one end to a ring (seal nose) which bears
either against a shoulder on the shaft or against a seal ring on the
shaft is called a:
a. rotating mechanical seal
b. setscrew seal
c. packing gland seal
d. bellows seal
e. diaphragm seal
, d. bellows seal
Duct liners:
a. Reduce the noise level of air flowing in the duct system.
b. Increase erosion to the duct.
c. Are primarily used to reduce fire hazard in non-metal duct
work.
d. Help to decrease the air pressure drop in ducting.
e. Are primarily used to eliminate corrosion in metal ducting.
a. Reduce the noise level of air flowing in the duct system.
Semi-rigid fibrous glass blankets attached to the insides of the
ducts are in place to mainly serve which function?
a. To stop leakage in the seams of the duct work.
b. To insulate.
c. To attenuate airborne noises.
d. To act as a fire retardant.
e. To restrict spread of smoke.
c. To attenuate airborne noises.
A type of fan which is unable to produce high pressures and
cannot be used in ducted air distribution systems is the
__________.
a. forward curve fan
b. centrifugal fan
c. vane axial fan
Complete Solutions
Which of the following devices has a de-clutching feature?
a. A variable speed motor control.
b. A fluid drive.
c. An outlet damper control.
d. A V-belt drive.
e. A variable inlet vane control.
b. A fluid drive.
The type of operation which stops the compressor when the
desired low temperature of the substance to be cooled is reached
and starts the compressor up again when the temperature rises to
a set level is called:
a. cylinder bypass operation
b. variable guide operation
c. intermittent operation
d. unloading operation
e. continuous operation with reduced output
c. intermittent operation
To prevent freezing of downstream equipment in a coil handling
a large amount of outdoor air, which of the following is
required?
,a. A preheat coil.
b. Two-Position damper motor.
c. A long coil length.
d. An oversized coil.
e. A vacuum breaker.
a. A preheat coil.
Steam coils:
a. Do not require a vacuum breaker.
b. Do not require air venting.
c. Should be installed with tubes in a vertical position to ensure
positive condensate drainage.
d. Are installed exactly the same as are glycol coils.
e. When installed in the horizontal position, do not have to be
pitched toward the return.
c. Should be installed with tubes in a vertical position to ensure
positive condensate drainage.
When all supply air duct is outside the conditioned space there is
a certain leakage. This leakage must be calculated how?
a. It must be added to the calculated room specific latent
humidity load.
b. It must be subtracted from the return air duct leakage.
c. It need not be considered in loss calculation.
d. It must be added to the calculated room sensible heat load.
e. It must be added to the return air duct leakage.
d. It must be added to the calculated room sensible heat load.
,The two general groups of fans are:
a. Centrifugal and axial flow.
b. Rotary positive displacement and centrifugal.
c. Reciprocating and axial flow.
d. Positive displacement and axial flow.
e. Reciprocating and centrifugal.
a. Centrifugal and axial flow.
This type of drive is normally used on small fan coil units to
heat or cool the perimeter areas of a building.
a. direct drive
b. variable inlet vane control
c. variable speed motor control
d. v-belt drive
e. fluid drive
a. direct drive
A typical stationary crankshaft seal consisting of a metallic
bellows soldered at one end to a ring (seal nose) which bears
either against a shoulder on the shaft or against a seal ring on the
shaft is called a:
a. rotating mechanical seal
b. setscrew seal
c. packing gland seal
d. bellows seal
e. diaphragm seal
, d. bellows seal
Duct liners:
a. Reduce the noise level of air flowing in the duct system.
b. Increase erosion to the duct.
c. Are primarily used to reduce fire hazard in non-metal duct
work.
d. Help to decrease the air pressure drop in ducting.
e. Are primarily used to eliminate corrosion in metal ducting.
a. Reduce the noise level of air flowing in the duct system.
Semi-rigid fibrous glass blankets attached to the insides of the
ducts are in place to mainly serve which function?
a. To stop leakage in the seams of the duct work.
b. To insulate.
c. To attenuate airborne noises.
d. To act as a fire retardant.
e. To restrict spread of smoke.
c. To attenuate airborne noises.
A type of fan which is unable to produce high pressures and
cannot be used in ducted air distribution systems is the
__________.
a. forward curve fan
b. centrifugal fan
c. vane axial fan
