Power Engineering - 4B11 Practice Questions With
Complete Solutions
In a pulse combination furnace the stated efficiency is:
a. 50 - 60%
b. 60 - 70%
c. 80 - 95%
d. 70 - 75%
e. 94 - 98%
e. 94 - 98%
Electric motors:
a. do not require any maintenance
b. all of the answers
c. only have sleeve bearings
d. bearings for electric motors require no lubrication
e. are rugged and simple machines
e. are rugged and simple machines
In regard to electric heating, the main disadvantage is:
a. an electrician is required to repair the system
b. poor local temperature control
c. high maintenance cost
d. all of the answers
e. expensive installation
,a. an electrician is required to repair the system
Air filters can be divided into two groups
a. electronic and steam
b. mechanical and electronic
c. mechanical and rotating drum
d. steam and rotating drum
e. dry and wet
b. mechanical and electronic
The perimeter loop system of furnace ducting is ideal for a
building with:
a. low head room in the basement
b. no insulation in the walls
c. no cold air returns
d. no basement
e. concrete walls
d. no basement
Which of the following are used for direct heating:
a. all of the answers
b. unit ventilators
c. unit heaters
d. radiant panel heaters
a. all of the answers
,Which of the following are used for indirect heating:
a. electric boilers
b. radiant panel heaters
c. unit ventilators
d. unit heaters
a. electric boilers
The main advantage of electric heating is:
a. electric heating devices produce no toxic gages
b. operating cost is lower
c. all of the answers
d. an electrician is required to repair the system
a. electric heating devices produce no toxic gages
The vent damper minimizes heat loss up the stack:
a. by increasing combustion air flow
b. when burners are on
c. by shutting off burners
d. by reducing firing rate
e. when burners are off
e. when burners are off
Furnace efficiency can be improved by
a. using electronic ignition
b. installation of a vent damper
, c. adding a secondary heat exchanger
d. improving heat exchanger design
e. all of the answers
e. all of the answers
Which three items give the forced warm air system a definite
advantage over steam and hot water heating systems?
1. The ducts are much smaller
2. Air may be cleaned by filters
3. Air can be humidified by using a humidifier
4. Controlled quantities of external ventilation air may be drawn
into the system
5. Blower noise can be carried through the ducts
a. 1, 3, 4
b. 1, 3, 5
c. 1, 2, 3
d. 2, 3, 4
e. 1, 2, 4
d. 2, 3, 4
The airborne contaminants are removed from the plates of
electronic air filters by:
a. blast of high pressure air
b. reversal of the air flow direction through the filter
c. using a rapper system to knock the particles loose
d. periodic replacement of the plates
e. washing
Complete Solutions
In a pulse combination furnace the stated efficiency is:
a. 50 - 60%
b. 60 - 70%
c. 80 - 95%
d. 70 - 75%
e. 94 - 98%
e. 94 - 98%
Electric motors:
a. do not require any maintenance
b. all of the answers
c. only have sleeve bearings
d. bearings for electric motors require no lubrication
e. are rugged and simple machines
e. are rugged and simple machines
In regard to electric heating, the main disadvantage is:
a. an electrician is required to repair the system
b. poor local temperature control
c. high maintenance cost
d. all of the answers
e. expensive installation
,a. an electrician is required to repair the system
Air filters can be divided into two groups
a. electronic and steam
b. mechanical and electronic
c. mechanical and rotating drum
d. steam and rotating drum
e. dry and wet
b. mechanical and electronic
The perimeter loop system of furnace ducting is ideal for a
building with:
a. low head room in the basement
b. no insulation in the walls
c. no cold air returns
d. no basement
e. concrete walls
d. no basement
Which of the following are used for direct heating:
a. all of the answers
b. unit ventilators
c. unit heaters
d. radiant panel heaters
a. all of the answers
,Which of the following are used for indirect heating:
a. electric boilers
b. radiant panel heaters
c. unit ventilators
d. unit heaters
a. electric boilers
The main advantage of electric heating is:
a. electric heating devices produce no toxic gages
b. operating cost is lower
c. all of the answers
d. an electrician is required to repair the system
a. electric heating devices produce no toxic gages
The vent damper minimizes heat loss up the stack:
a. by increasing combustion air flow
b. when burners are on
c. by shutting off burners
d. by reducing firing rate
e. when burners are off
e. when burners are off
Furnace efficiency can be improved by
a. using electronic ignition
b. installation of a vent damper
, c. adding a secondary heat exchanger
d. improving heat exchanger design
e. all of the answers
e. all of the answers
Which three items give the forced warm air system a definite
advantage over steam and hot water heating systems?
1. The ducts are much smaller
2. Air may be cleaned by filters
3. Air can be humidified by using a humidifier
4. Controlled quantities of external ventilation air may be drawn
into the system
5. Blower noise can be carried through the ducts
a. 1, 3, 4
b. 1, 3, 5
c. 1, 2, 3
d. 2, 3, 4
e. 1, 2, 4
d. 2, 3, 4
The airborne contaminants are removed from the plates of
electronic air filters by:
a. blast of high pressure air
b. reversal of the air flow direction through the filter
c. using a rapper system to knock the particles loose
d. periodic replacement of the plates
e. washing
