ELECTRICAL ENGINEERING MY POWER 4B3
MULTIPLE CHOICE QUESTIONS AND
ANSWERS 100% VERIFIED.
At the end of the pre-purge period, the programming control:
Select one:
a. Opens the main fuel valve
b. Closes the pilot valve
c. Ends the ignition trial
d. Energizes the ignition transformer
Verified Answer -d. Energizes the ignition transformer
A steam boiler is regularly blown off in order to:
Select one:
a. Clean the soot and carbon out of the firebox and tubes
b. Lower the operating water level in the boiler
c. Discharge sediment from the boiler
d. Test the rated relieving capacity of the safety valves fitted to the boiler
Verified Answer -c. Discharge sediment from the boiler
A flame failure device is unresponsive to:
Select one:
a. Ultraviolet light
b. Infra-red light
c. Visible light
,d. Fuel flow
Verified Answer -d. Fuel flow
The popping pressure of a safety valve ________________ without
replacing its spring:
Select one:
a. Cannot be changed
b. Can only be increased by 5%
c. Can only be decreased by 5%
d. Can be changed by plus or minus 5%
Verified Answer -d. Can be changed by plus or minus 5%
A mercury switch bulb is under high vacuum and contains inert gas:
Select one:
a. So it will not explode
b. To keep the mercury from oxidizing
c. To decrease electrical resistance
d. So the contacts will not overheat
Verified Answer -b. To keep the mercury from oxidizing
The purpose of the spring in a safety valve is to:
Select one:
a. Help open the testing lever
b. Adjust the pressure setting of the valve
c. Adjust the blow down of the valve
, d. Hold down the disc on the seat
Verified Answer -d. Hold down the disc on the seat
A thermocouple:
Select one:
a. Consists of two similar wires
b. Produces an electric signal
c. Senses infrared light from the flame
d. Is made of several thermopiles connected in series
Verified Answer -b. Produces an electric signal
The lowest visible point of the gauge glass for a horizontal firetube power
boiler with diameter greater than 400 mm must be:
Select one:
a. Level with the highest fire tube
b. Level with the normal water level
c. 25 mm below the highest fire tube
d. 75 mm above the lowest permissible water level
Verified Answer -d. 75 mm above the lowest permissible water level
A flame rod:
Select one:
a. Is used in combination with a photocell
b. Is used only for oil fired burners
c. Forms an electric circuit with the rod, flame and burner
MULTIPLE CHOICE QUESTIONS AND
ANSWERS 100% VERIFIED.
At the end of the pre-purge period, the programming control:
Select one:
a. Opens the main fuel valve
b. Closes the pilot valve
c. Ends the ignition trial
d. Energizes the ignition transformer
Verified Answer -d. Energizes the ignition transformer
A steam boiler is regularly blown off in order to:
Select one:
a. Clean the soot and carbon out of the firebox and tubes
b. Lower the operating water level in the boiler
c. Discharge sediment from the boiler
d. Test the rated relieving capacity of the safety valves fitted to the boiler
Verified Answer -c. Discharge sediment from the boiler
A flame failure device is unresponsive to:
Select one:
a. Ultraviolet light
b. Infra-red light
c. Visible light
,d. Fuel flow
Verified Answer -d. Fuel flow
The popping pressure of a safety valve ________________ without
replacing its spring:
Select one:
a. Cannot be changed
b. Can only be increased by 5%
c. Can only be decreased by 5%
d. Can be changed by plus or minus 5%
Verified Answer -d. Can be changed by plus or minus 5%
A mercury switch bulb is under high vacuum and contains inert gas:
Select one:
a. So it will not explode
b. To keep the mercury from oxidizing
c. To decrease electrical resistance
d. So the contacts will not overheat
Verified Answer -b. To keep the mercury from oxidizing
The purpose of the spring in a safety valve is to:
Select one:
a. Help open the testing lever
b. Adjust the pressure setting of the valve
c. Adjust the blow down of the valve
, d. Hold down the disc on the seat
Verified Answer -d. Hold down the disc on the seat
A thermocouple:
Select one:
a. Consists of two similar wires
b. Produces an electric signal
c. Senses infrared light from the flame
d. Is made of several thermopiles connected in series
Verified Answer -b. Produces an electric signal
The lowest visible point of the gauge glass for a horizontal firetube power
boiler with diameter greater than 400 mm must be:
Select one:
a. Level with the highest fire tube
b. Level with the normal water level
c. 25 mm below the highest fire tube
d. 75 mm above the lowest permissible water level
Verified Answer -d. 75 mm above the lowest permissible water level
A flame rod:
Select one:
a. Is used in combination with a photocell
b. Is used only for oil fired burners
c. Forms an electric circuit with the rod, flame and burner
