LINEMAN APPRENTICE RODEO
COMPREHENSIVE EXAMINATION TEST
COMPLETE QUESTIONS WITH ACCURATE
SOLUTIONS
●● Define an electric current.
Answer: The flow of free electrons when a voltage is applied.
●● Define a conductor.
Answer: Materials having many free electrons make good conductors of
electricity. Copper, Aluminum
●● Define an insulator.
Answer: Materials having few free electrons make poor conductors and
can be used to insulate electricity.
●● What are three samples of good insulators?
Answer: Glass, porcelain, rubber polyethylene and fiberglass.
●● What is the unit of electric current?
Answer: Amp or Ampere
,●● What instrument is used to measure electric current?
Answer: Ammeter
●● What is the unit of electric pressure?
Answer: Volt , Voltage is the electric force or pressure that is determined
by the potential difference between any two points in a circuit.
●● Draw a schematic diagram to illustrate the proper methods of
connecting instruments to a single-phase motor to measure electric
current and the electric pressure supplied to the motor. Voltmeter in
parallel, Ammeter in series.
Answer:
●● What is the unit of electric power?
Answer: Watt
●● Draw a schematic illustrating the method of connecting a wattmeter
in a single-phase circuit to measure the power consumed.
Answer:
●● What is the unit of electric energy?
Answer: Watt-hours or kWh Electricity must act for a period of time in
order to do useful work. The power expressed in watts tells how much
electricity is working, and the hours express the time during which it
,acts. The product of these two factors gives the amount of work done.
Power × Time = energy Watts × Hours = Watt Hours
●● What instrument is used to measure electric energy?
Answer: Watt-hour Meter (typical house meter)
●● What is the formula for Ohm's law?
Answer: E=I×R I = R=
●● Define an alternating current.
Answer:
●● What is the unit of an alternating-current frequency?
Answer: Number of Cycles per second Hertz or (Hz)
●● Define the power factor of an alternating-current circuit.
Answer: Power Factor - when an alternating voltage and the current
which it causes to flow rise and fall in value together and reverse
direction at the same instant, the two are said to be ' in phase' and the
power factor is unity. Watts = Volts × Amps × Power Factor Power
Factor =
●● Describe the theory of operation of an electric transformer.
, Answer:
●● Describe a typical electric system, itemizing the major parts of the
system
Answer: €Generation: Nuclear, Fossil Fuel, Hydro Electric €Generated
between 13,200 and 24,000 volts €Stepped up to transmission voltages
between 138,000 and 765,000volts€Transmission Substations step down
to Subtransmission voltages between 34,500 and 161,000 volts
€Distribution Substations step down to voltages between 4160/2400 and
34,500/19,920 volts -Underground and Overhead Branch Circuits •
Transformers step down voltages to 120/240, three phase voltages of
120/208 or 277/480.
●● What is a transmission line?
Answer: A set of conductors energized at voltages over 69,000 volts and
transmitting large blocks of electrical energy over relatively long
distances.
●● How do the voltage levels of transmission, sub-transmission, and
distribution lines compare?
Answer: High voltages used for AC transmission lines are 115,000;
138,000; 161,000 volts - Extra-High-voltage (EHV) Lines are energized
at 345,000 - 765,000 volts.
●● When are direct-current transmission lines used?
COMPREHENSIVE EXAMINATION TEST
COMPLETE QUESTIONS WITH ACCURATE
SOLUTIONS
●● Define an electric current.
Answer: The flow of free electrons when a voltage is applied.
●● Define a conductor.
Answer: Materials having many free electrons make good conductors of
electricity. Copper, Aluminum
●● Define an insulator.
Answer: Materials having few free electrons make poor conductors and
can be used to insulate electricity.
●● What are three samples of good insulators?
Answer: Glass, porcelain, rubber polyethylene and fiberglass.
●● What is the unit of electric current?
Answer: Amp or Ampere
,●● What instrument is used to measure electric current?
Answer: Ammeter
●● What is the unit of electric pressure?
Answer: Volt , Voltage is the electric force or pressure that is determined
by the potential difference between any two points in a circuit.
●● Draw a schematic diagram to illustrate the proper methods of
connecting instruments to a single-phase motor to measure electric
current and the electric pressure supplied to the motor. Voltmeter in
parallel, Ammeter in series.
Answer:
●● What is the unit of electric power?
Answer: Watt
●● Draw a schematic illustrating the method of connecting a wattmeter
in a single-phase circuit to measure the power consumed.
Answer:
●● What is the unit of electric energy?
Answer: Watt-hours or kWh Electricity must act for a period of time in
order to do useful work. The power expressed in watts tells how much
electricity is working, and the hours express the time during which it
,acts. The product of these two factors gives the amount of work done.
Power × Time = energy Watts × Hours = Watt Hours
●● What instrument is used to measure electric energy?
Answer: Watt-hour Meter (typical house meter)
●● What is the formula for Ohm's law?
Answer: E=I×R I = R=
●● Define an alternating current.
Answer:
●● What is the unit of an alternating-current frequency?
Answer: Number of Cycles per second Hertz or (Hz)
●● Define the power factor of an alternating-current circuit.
Answer: Power Factor - when an alternating voltage and the current
which it causes to flow rise and fall in value together and reverse
direction at the same instant, the two are said to be ' in phase' and the
power factor is unity. Watts = Volts × Amps × Power Factor Power
Factor =
●● Describe the theory of operation of an electric transformer.
, Answer:
●● Describe a typical electric system, itemizing the major parts of the
system
Answer: €Generation: Nuclear, Fossil Fuel, Hydro Electric €Generated
between 13,200 and 24,000 volts €Stepped up to transmission voltages
between 138,000 and 765,000volts€Transmission Substations step down
to Subtransmission voltages between 34,500 and 161,000 volts
€Distribution Substations step down to voltages between 4160/2400 and
34,500/19,920 volts -Underground and Overhead Branch Circuits •
Transformers step down voltages to 120/240, three phase voltages of
120/208 or 277/480.
●● What is a transmission line?
Answer: A set of conductors energized at voltages over 69,000 volts and
transmitting large blocks of electrical energy over relatively long
distances.
●● How do the voltage levels of transmission, sub-transmission, and
distribution lines compare?
Answer: High voltages used for AC transmission lines are 115,000;
138,000; 161,000 volts - Extra-High-voltage (EHV) Lines are energized
at 345,000 - 765,000 volts.
●● When are direct-current transmission lines used?
