TCM 322 EXAM 1 QUESTIONS WITH
CORRECT ANSWERS | ALREADY
PASSED
What is NM cable? - Answer- Non-metallic (Romex) usual sizes are 14-2,14-3,12-2,12-
3- used in homes and small commercial
What is UF Cable? - Answer- Underground feeder used in residential. It is typically non-
metallic
What is SE Cable? - Answer- Service entrance cable, used to run from the meter to the
main, from the main to the sub, or to feed large appliances. Can be ran in or out of a
raceway.
What is the advantage of a four wire system? - Answer- It provides both 3 phase and
single phase power
Who governs the method of bringing in power to a building? - Answer- Local Utility
Companies
How many service entrances are allowed per building? - Answer- One.... the exceptions
are 230.2 Emergency, fire pumps, etc.
Pad mounted transformers can be used for smaller service entrances, but how are
larger ones configured? - Answer- Unit substations
Underground Vaults
Occupants should have access to their supply disconnect. What is the exception? -
Answer- If it is under constant monitoring by the building management
How many Amps does it take to cause death? - Answer- 20mA
How many Volts does it take to cause death? - Answer- Dry- 2000V
Wet- 20V
What limits the amount of current a wire or cable can carry? - Answer- The allowable
temp rating of the conductor's insulation
What is the most common type of insulation? - Answer- Thermoplastic- THW, THHN,
etc.
, What is AC Cable? - Answer- Armored Cable- (Bx)
DRY LOCATIONS ONLY
What is MC Cable? - Answer- Metal Clad- Can be used in wet locations with a pvc
jacket. nIt is heavier than BX cable
What is FC Cable? - Answer- Flat cable- it is used in factories and warehouses where
large equipment is moved around. It is the kind that has the long runways that the
fixtures can be moved around on.
What is Current? (Definition, Unit of Measurement, Symbol) - Answer- The rate of flow
for an electrical charge. It is measure in Amperes (Amps) and the symbol is (I)
What is Voltage? (Definition, Unit of Measurement, Symbol) - Answer- It is what makes
electrons flow (think of it as a pressure). It is measured in volts, and the symbol is (E) or
(V).
What is used to define voltage? - Answer- Power..... 1 watt produces a flow of 1 amp
across a potential of 1 volt. Most batteries are 1.5 Volt. A fridge and TV are 120V.
What is DC Current? - Answer- Direct Current.. In DC, Voltage and Current never vary.
Think of flashlights, phones, cars.
What is AC Current? - Answer- Alternating Current. Voltage and Current vary with time.
Think of buildings, outlets, lights, elevators.
What is frequency measured in, and what is the frequency of US and Foreign Power? -
Answer- Hertz
US- 60 Hz
Foreign Countries- 50 Hz
What are the two types of AC Power? - Answer- Single Phase
Three Phase
What is Resistance? (Definition, Unit of Measurement, Symbol) - Answer- Resistance is
the opposition to the flow of current. it is measured in Ohms and the symbol is (R). 1
Ohm allows a current of 1 Amp at 1 Volt.
What is Impedance? (Definition, Unit of Measurement, Symbol) - Answer- Impedance is
pretty much the same thing as Resistance, but for AC Applications. It is measure in
Ohms as well. Symbol = (Z)
What is Capacitance? - Answer- the ability to store energy in an electric field.
What does the term dielectric mean? - Answer- It is a nonconductor of electricity
CORRECT ANSWERS | ALREADY
PASSED
What is NM cable? - Answer- Non-metallic (Romex) usual sizes are 14-2,14-3,12-2,12-
3- used in homes and small commercial
What is UF Cable? - Answer- Underground feeder used in residential. It is typically non-
metallic
What is SE Cable? - Answer- Service entrance cable, used to run from the meter to the
main, from the main to the sub, or to feed large appliances. Can be ran in or out of a
raceway.
What is the advantage of a four wire system? - Answer- It provides both 3 phase and
single phase power
Who governs the method of bringing in power to a building? - Answer- Local Utility
Companies
How many service entrances are allowed per building? - Answer- One.... the exceptions
are 230.2 Emergency, fire pumps, etc.
Pad mounted transformers can be used for smaller service entrances, but how are
larger ones configured? - Answer- Unit substations
Underground Vaults
Occupants should have access to their supply disconnect. What is the exception? -
Answer- If it is under constant monitoring by the building management
How many Amps does it take to cause death? - Answer- 20mA
How many Volts does it take to cause death? - Answer- Dry- 2000V
Wet- 20V
What limits the amount of current a wire or cable can carry? - Answer- The allowable
temp rating of the conductor's insulation
What is the most common type of insulation? - Answer- Thermoplastic- THW, THHN,
etc.
, What is AC Cable? - Answer- Armored Cable- (Bx)
DRY LOCATIONS ONLY
What is MC Cable? - Answer- Metal Clad- Can be used in wet locations with a pvc
jacket. nIt is heavier than BX cable
What is FC Cable? - Answer- Flat cable- it is used in factories and warehouses where
large equipment is moved around. It is the kind that has the long runways that the
fixtures can be moved around on.
What is Current? (Definition, Unit of Measurement, Symbol) - Answer- The rate of flow
for an electrical charge. It is measure in Amperes (Amps) and the symbol is (I)
What is Voltage? (Definition, Unit of Measurement, Symbol) - Answer- It is what makes
electrons flow (think of it as a pressure). It is measured in volts, and the symbol is (E) or
(V).
What is used to define voltage? - Answer- Power..... 1 watt produces a flow of 1 amp
across a potential of 1 volt. Most batteries are 1.5 Volt. A fridge and TV are 120V.
What is DC Current? - Answer- Direct Current.. In DC, Voltage and Current never vary.
Think of flashlights, phones, cars.
What is AC Current? - Answer- Alternating Current. Voltage and Current vary with time.
Think of buildings, outlets, lights, elevators.
What is frequency measured in, and what is the frequency of US and Foreign Power? -
Answer- Hertz
US- 60 Hz
Foreign Countries- 50 Hz
What are the two types of AC Power? - Answer- Single Phase
Three Phase
What is Resistance? (Definition, Unit of Measurement, Symbol) - Answer- Resistance is
the opposition to the flow of current. it is measured in Ohms and the symbol is (R). 1
Ohm allows a current of 1 Amp at 1 Volt.
What is Impedance? (Definition, Unit of Measurement, Symbol) - Answer- Impedance is
pretty much the same thing as Resistance, but for AC Applications. It is measure in
Ohms as well. Symbol = (Z)
What is Capacitance? - Answer- the ability to store energy in an electric field.
What does the term dielectric mean? - Answer- It is a nonconductor of electricity
