ABSA 4th Class Exam Part 1 Practice
Questions and Answers154
Soot blower Operation - ANSWERS -During soot blowing, the boilers should be operating at a
minimum of 50 percent load to ensure stable combustion. Furnace pressure should be below
atmospheric, to prevent blowback through inspection doors and openings.
Falling shot cleaning - ANSWERS -Uses 6mm pellets
- falls by gravity
- Hopper at bottom collects and return to distributing chamber pneumatically.
Advantages:
- Supply of air or steam for the operation of soot blowers is not required.
- in small plants, the turbine steam supply is not affected by the steam consumption of the soot
blowers.
Absolute pressure is: - ANSWERS -gauge pressure plus atmospheric pressure
The motion of moving parts is _____ by friction:
A: Prevented
B: Improved
C: controlled
D: resisted
,E: Regulated - ANSWERS -D: resisted
Voltage is
a) the rate of current flow
b) the rate of electron flow
c) electromotive force
d) Kinetic energy
e) A form of power - ANSWERS -c) electromotive force
The resistance of a conductor is affected by:
1. Cross section area
2. Length
3. Temperature
4. Type of material
a) 1,2,3
b) 1,2,4
c) 1,3
d) 1,2,3,4
e) 1,2 - ANSWERS -d) 1,2,3,4
The movement of electrons in a conductor can be measured in:
a) Amperes
b) Ohms
,c) Volts
d) Watts
e) Micrometer - ANSWERS -a) Amperes
An electric motor has a 3/4 horse power output rating. Calculate the rating in kilowatts:
a) 0.56
b) 0.75
c) 0.70
d) 7.5
e) 1.005 - ANSWERS -a) 0.56
The connection provided on DC motors to supply the armature with power:
a) are slip rings
b) are field poses
c) is a rheostat
d) commutator
e) is a rotating conductor - ANSWERS -d) commutator
The unit for the oppostion to current flow is the:
a) volt
b) amperes
c) ohm
d) watt
, e) resistance - ANSWERS -c) ohm
In an electric circuit protected by a single fuse the current flowing through the fuse must be:
a) Equal to the voltage in the circuit
b) Equal to the resistance in the circuit
c) All of the current in the circuit
d) Equal to the rated value of the fuse
e) 1.732 times the applied current - ANSWERS -d) Equal to the rated value of the fuse
Electric overloads may be due to
1. Applying too heavy load to an electric motor
2. Lightning strike
3. A short circuit
4. Overloading a circuit with too many devices
5. Addition of circuit breakers
a) 1,2,3,4
b) 1,3,4,5
c) 1,2,5
d) 2,3,4
e) 1,3,5 - ANSWERS -a) 1,2,3,4
Since the discovery of electrons, it has been determined that electrons are a negative charge
and flow from:
Questions and Answers154
Soot blower Operation - ANSWERS -During soot blowing, the boilers should be operating at a
minimum of 50 percent load to ensure stable combustion. Furnace pressure should be below
atmospheric, to prevent blowback through inspection doors and openings.
Falling shot cleaning - ANSWERS -Uses 6mm pellets
- falls by gravity
- Hopper at bottom collects and return to distributing chamber pneumatically.
Advantages:
- Supply of air or steam for the operation of soot blowers is not required.
- in small plants, the turbine steam supply is not affected by the steam consumption of the soot
blowers.
Absolute pressure is: - ANSWERS -gauge pressure plus atmospheric pressure
The motion of moving parts is _____ by friction:
A: Prevented
B: Improved
C: controlled
D: resisted
,E: Regulated - ANSWERS -D: resisted
Voltage is
a) the rate of current flow
b) the rate of electron flow
c) electromotive force
d) Kinetic energy
e) A form of power - ANSWERS -c) electromotive force
The resistance of a conductor is affected by:
1. Cross section area
2. Length
3. Temperature
4. Type of material
a) 1,2,3
b) 1,2,4
c) 1,3
d) 1,2,3,4
e) 1,2 - ANSWERS -d) 1,2,3,4
The movement of electrons in a conductor can be measured in:
a) Amperes
b) Ohms
,c) Volts
d) Watts
e) Micrometer - ANSWERS -a) Amperes
An electric motor has a 3/4 horse power output rating. Calculate the rating in kilowatts:
a) 0.56
b) 0.75
c) 0.70
d) 7.5
e) 1.005 - ANSWERS -a) 0.56
The connection provided on DC motors to supply the armature with power:
a) are slip rings
b) are field poses
c) is a rheostat
d) commutator
e) is a rotating conductor - ANSWERS -d) commutator
The unit for the oppostion to current flow is the:
a) volt
b) amperes
c) ohm
d) watt
, e) resistance - ANSWERS -c) ohm
In an electric circuit protected by a single fuse the current flowing through the fuse must be:
a) Equal to the voltage in the circuit
b) Equal to the resistance in the circuit
c) All of the current in the circuit
d) Equal to the rated value of the fuse
e) 1.732 times the applied current - ANSWERS -d) Equal to the rated value of the fuse
Electric overloads may be due to
1. Applying too heavy load to an electric motor
2. Lightning strike
3. A short circuit
4. Overloading a circuit with too many devices
5. Addition of circuit breakers
a) 1,2,3,4
b) 1,3,4,5
c) 1,2,5
d) 2,3,4
e) 1,3,5 - ANSWERS -a) 1,2,3,4
Since the discovery of electrons, it has been determined that electrons are a negative charge
and flow from:
