APPRENTICE LINEMAN GENERAL KNOWLEDGE STUDY GUIDE
QUESTIONS WITH ANSWERS 2025/2026 GRADED A+
What is it called when a change of current in a coil induces an EMF in the same coil? -
self induction
The direction of flow of an induced EMF is always in which direction? - The direction
that opposes the change of current that caused it.
When a conductor is moved through magnetic lines of force what happens? - An EMF is
induced
A straight line drawn from the center of a circle to its outer edge is called the
__________. - radius
A straight line drawn through the center of a circle that touches the circle in two places
is called what? - diameter
The distance around a circle is called the __________. - circumference
What is the formula to find the circumference of a circle? - C = 3.14 x D
Where: D = diameter of circle
What is the formula to find the Area of a circle? - A = 3.14 x R²
Where: R = radius of circle
To prevent a series circuit from being completely interrupted by a burn out of one lamp,
__________ __________ __________ are used. - film disk cutout
What should always be done before opening a series circuit? - Drop load and take out
of service.
If raising a transformer causes temporary excessive strain to the pole what should be
done? - Install a temporary guy
As a rule what polarity are distribution transformers? - Additive (below 200kVA & below
8,660 V)
What protects direct burial cable from: moisture, gases, chemicals, and mechanical
injury during installation? - sheathes
What are sheathes made of? - plastic or lead
What is tracking? - Flow of electricity that causes damage to insulators.
Why must you be careful to adequately ground neutral conductors? - So fault current
can dissipate before causing damage to cable or equipment.
,What is the purpose of armor rods? - Protect the conductor from chafing, dampening
vibration, protect from flashover burns.
Stockbridge damper is designed to prevent what? - Resonant Vibration
When a wye secondary is used on any bank what should be done with the neutral? -
solidly grounded
Bending hot sticks should be kept to a __________ ? - minimum
The current in a transformer winding when connected delta is: - line current ÷ 1.73
How does winding voltage compare with line voltage when transformers are connected
delta? - winding voltage = line voltage
The voltage across transformer windings when connected wye is: - winding voltage =
line voltage ÷ 1.73
How does winding current compare with line current when transformers are connected
wye? - line current = winding current
To convert an underground cable to an overhead line requires _________ and a
__________. - riser, pothead
If an underground riser is low voltage it terminates in a __________ __________. -
weather head
If the termination is high voltage it terminates in a _________. - pothead
Name two types of potheads? - 1. one conductor
2. three conductor
How is a pothead attached to the sheath of the cable? - wiped joint or a clamping joint
What is the purpose of a pothead? - To separate conductors and to seal out water.
What is another name for galvanic action? - electrolysis
What determines how the secondary of a bank is hooked up? - customer demands
What are the formulas for finding the capacity of an open bank? - 57.7% of total closed
bank, or 86.6% of remaining cans
What should be hooked up first when installing a transformer on transformer bank? -
grounds and then neutral
, What are the three ways to sag a conductor? - 1. Dynamometer
2. Timing mechanical waves with a unisagwatch
3. Transit
What are the four principle types of electric discharge lamps? - 1. Sodium
2. Mercury vapor
3. Halide
4. Florescent
How does an incandescent lamp work? - A wire filament sealed in a glass tube with the
air pumped out is heated by a electric current that causes it to glow, it must be heated to
5000°F
What are lamps rated output in? - lumens
The highest value that a demand reaches is called the __________ __________ . -
Peak (max.) demand
What determines the size and type of equipment necessary to supply the consumer? -
Max. demand
What is the formula to determine load factor? - Load Factor = Average Demand ÷
Maximum Demand
How much can a booster transformer boost line voltage? - 5% or 10%
How should the secondary coils be connected to boost the voltage 5%? - parallel
How should the secondary coils be connected to boost the voltage 10%? - series
A booster transformer is connected with the primary in __________ with the line, and
the secondary in __________ with the line. - parallel, series
What are the three types of overhead line faluts? - 1. Open circuit
2. Cross circuit
3. Short circuit
Grounded Circuit
How does a maximeter work? - On the transformer principle with the primary being the
conductor, and the meter coil being the secondary.
What do most maximeter scales read? - 0 to 6 amps, but to read more a multiplier is
provided.
QUESTIONS WITH ANSWERS 2025/2026 GRADED A+
What is it called when a change of current in a coil induces an EMF in the same coil? -
self induction
The direction of flow of an induced EMF is always in which direction? - The direction
that opposes the change of current that caused it.
When a conductor is moved through magnetic lines of force what happens? - An EMF is
induced
A straight line drawn from the center of a circle to its outer edge is called the
__________. - radius
A straight line drawn through the center of a circle that touches the circle in two places
is called what? - diameter
The distance around a circle is called the __________. - circumference
What is the formula to find the circumference of a circle? - C = 3.14 x D
Where: D = diameter of circle
What is the formula to find the Area of a circle? - A = 3.14 x R²
Where: R = radius of circle
To prevent a series circuit from being completely interrupted by a burn out of one lamp,
__________ __________ __________ are used. - film disk cutout
What should always be done before opening a series circuit? - Drop load and take out
of service.
If raising a transformer causes temporary excessive strain to the pole what should be
done? - Install a temporary guy
As a rule what polarity are distribution transformers? - Additive (below 200kVA & below
8,660 V)
What protects direct burial cable from: moisture, gases, chemicals, and mechanical
injury during installation? - sheathes
What are sheathes made of? - plastic or lead
What is tracking? - Flow of electricity that causes damage to insulators.
Why must you be careful to adequately ground neutral conductors? - So fault current
can dissipate before causing damage to cable or equipment.
,What is the purpose of armor rods? - Protect the conductor from chafing, dampening
vibration, protect from flashover burns.
Stockbridge damper is designed to prevent what? - Resonant Vibration
When a wye secondary is used on any bank what should be done with the neutral? -
solidly grounded
Bending hot sticks should be kept to a __________ ? - minimum
The current in a transformer winding when connected delta is: - line current ÷ 1.73
How does winding voltage compare with line voltage when transformers are connected
delta? - winding voltage = line voltage
The voltage across transformer windings when connected wye is: - winding voltage =
line voltage ÷ 1.73
How does winding current compare with line current when transformers are connected
wye? - line current = winding current
To convert an underground cable to an overhead line requires _________ and a
__________. - riser, pothead
If an underground riser is low voltage it terminates in a __________ __________. -
weather head
If the termination is high voltage it terminates in a _________. - pothead
Name two types of potheads? - 1. one conductor
2. three conductor
How is a pothead attached to the sheath of the cable? - wiped joint or a clamping joint
What is the purpose of a pothead? - To separate conductors and to seal out water.
What is another name for galvanic action? - electrolysis
What determines how the secondary of a bank is hooked up? - customer demands
What are the formulas for finding the capacity of an open bank? - 57.7% of total closed
bank, or 86.6% of remaining cans
What should be hooked up first when installing a transformer on transformer bank? -
grounds and then neutral
, What are the three ways to sag a conductor? - 1. Dynamometer
2. Timing mechanical waves with a unisagwatch
3. Transit
What are the four principle types of electric discharge lamps? - 1. Sodium
2. Mercury vapor
3. Halide
4. Florescent
How does an incandescent lamp work? - A wire filament sealed in a glass tube with the
air pumped out is heated by a electric current that causes it to glow, it must be heated to
5000°F
What are lamps rated output in? - lumens
The highest value that a demand reaches is called the __________ __________ . -
Peak (max.) demand
What determines the size and type of equipment necessary to supply the consumer? -
Max. demand
What is the formula to determine load factor? - Load Factor = Average Demand ÷
Maximum Demand
How much can a booster transformer boost line voltage? - 5% or 10%
How should the secondary coils be connected to boost the voltage 5%? - parallel
How should the secondary coils be connected to boost the voltage 10%? - series
A booster transformer is connected with the primary in __________ with the line, and
the secondary in __________ with the line. - parallel, series
What are the three types of overhead line faluts? - 1. Open circuit
2. Cross circuit
3. Short circuit
Grounded Circuit
How does a maximeter work? - On the transformer principle with the primary being the
conductor, and the meter coil being the secondary.
What do most maximeter scales read? - 0 to 6 amps, but to read more a multiplier is
provided.
