Basic Electrical Theory Final Exam Questions
and Answers.
Electricity:
An electrical arc blast can vaporize metal parts and produces an explosive and deadly
pressure wave. How many degrees Fahrenheit can an electrical arc blast reach? -
Correct answer 30,000 degrees Fahrenheit
Electric Motors:
Does the electric motor work on the principle of the attracting and repelling forces of
magnetic fields? - Correct answer Yes
Electromagnetic Relay:
Is a holding relay primarily used for worker convenience? - Correct answer No
Current Flow on the Neutral Conductor:
A balanced 3-wire, 120/240, single-phase circuit is connected so that the ungrounded
conductors are from different transformer phases (line 1 and Line 2.) The current on the
neutral conductor will be how much percent of the ungrounded conductor current? -
Correct answer 0%
Interrupting Rating:
If the protection device is not rated to interrupt the current at the available fault values at
its listed voltage rating, it can explode while attempting to clear the fault correct? -
Correct answer Yes
Sine Wave:
A no sinusoidal waveform is created when NONLINEAR loads distort the voltage and
current sine wave. True or false? - Correct answer True
Phase Relationship:
The opposition offered to the flow of ac current by a capacitor is called "capacitive
reactance," which is expressed in ohms and abbreviated how? - Correct answer X of c
Induced Voltage and Applied Current:
The induced voltage in a conductor carrying alternating current opposes the change in
current flowing through the conductor. The induced voltage that opposes the current
, flow is interchangeably called what three things? - Correct answer CEMF, Counter-
Electromotive force, and Back-EMF
Impedance:
What is the total opposition to current flow in ac circuits and is measured in ohms? -
Correct answer impedance
Impedance:
Z is the abbreviation for what? - Correct answer Impedance
Current Flow:
Self-induced voltage opposes the change in current flowing in the conductor, is called
"inductive reactance" and is abbreviated how? - Correct answer X of l
Dual-Voltage AC Motors:
Dual-voltage ac motors are made with two field windings. How are the field winding
connected for low-Voltage operation? - Correct answer Parallel.
Dual-Voltage AC Motors:
Dual-voltage ac motors are made with two field windings. How are the field windings
connected for high-voltage operation? - Correct answer Series
Motor Current Ratings:
The motor FLA rating is used when sizing motor conductor size or circuit protection?
True or False? - Correct answer False
Motor Starting Current:
When a motor starts, the current drawn is approximately 6 times the motor FLA; this is
known as what? - Correct answer "motor locked-rotor amperes" or (LRA).
Reversing the Rotation of an AC Motor:
Swapping two of the line conductors can reverse a kind of ac motor's rotation? - Correct
answer 3-phase
Transformer Basics:
and Answers.
Electricity:
An electrical arc blast can vaporize metal parts and produces an explosive and deadly
pressure wave. How many degrees Fahrenheit can an electrical arc blast reach? -
Correct answer 30,000 degrees Fahrenheit
Electric Motors:
Does the electric motor work on the principle of the attracting and repelling forces of
magnetic fields? - Correct answer Yes
Electromagnetic Relay:
Is a holding relay primarily used for worker convenience? - Correct answer No
Current Flow on the Neutral Conductor:
A balanced 3-wire, 120/240, single-phase circuit is connected so that the ungrounded
conductors are from different transformer phases (line 1 and Line 2.) The current on the
neutral conductor will be how much percent of the ungrounded conductor current? -
Correct answer 0%
Interrupting Rating:
If the protection device is not rated to interrupt the current at the available fault values at
its listed voltage rating, it can explode while attempting to clear the fault correct? -
Correct answer Yes
Sine Wave:
A no sinusoidal waveform is created when NONLINEAR loads distort the voltage and
current sine wave. True or false? - Correct answer True
Phase Relationship:
The opposition offered to the flow of ac current by a capacitor is called "capacitive
reactance," which is expressed in ohms and abbreviated how? - Correct answer X of c
Induced Voltage and Applied Current:
The induced voltage in a conductor carrying alternating current opposes the change in
current flowing through the conductor. The induced voltage that opposes the current
, flow is interchangeably called what three things? - Correct answer CEMF, Counter-
Electromotive force, and Back-EMF
Impedance:
What is the total opposition to current flow in ac circuits and is measured in ohms? -
Correct answer impedance
Impedance:
Z is the abbreviation for what? - Correct answer Impedance
Current Flow:
Self-induced voltage opposes the change in current flowing in the conductor, is called
"inductive reactance" and is abbreviated how? - Correct answer X of l
Dual-Voltage AC Motors:
Dual-voltage ac motors are made with two field windings. How are the field winding
connected for low-Voltage operation? - Correct answer Parallel.
Dual-Voltage AC Motors:
Dual-voltage ac motors are made with two field windings. How are the field windings
connected for high-voltage operation? - Correct answer Series
Motor Current Ratings:
The motor FLA rating is used when sizing motor conductor size or circuit protection?
True or False? - Correct answer False
Motor Starting Current:
When a motor starts, the current drawn is approximately 6 times the motor FLA; this is
known as what? - Correct answer "motor locked-rotor amperes" or (LRA).
Reversing the Rotation of an AC Motor:
Swapping two of the line conductors can reverse a kind of ac motor's rotation? - Correct
answer 3-phase
Transformer Basics:
