Safety First
The safest ladder to use around electricity would be made mainly out of what material?
Fiberglass
What are the three parts required to make a circuit?
1. Source
2. Load
3. Conductor
What is the most commonly used conductor?
Copper but Silver actually has the highest conductivity of all metals!
What is a transformer used for?
To either step up (raise) or step down (lower) the voltage.
How many watts are in one kilowatt?
1000
1000 watts = 1 kilowatt
How often should a pair of insulated gloves be visually inspected?
Before each and every use.
Do not get shocked!!
Is a size 4 AWG conductor smaller or bigger in size than a size 12 AWG conductor?
Bigger.
Remember that when using the AWG, the bigger the number, the smaller the gauge.
What is a trade name for non-metallic cabling?
Romex
An electrical cable must extend how far into an electrical box?
Minimum of 6 inches.
This is code to allow for enough wire to actually work with.
What is the formula for Ohm's Law?
Voltage (V) = Current (I) x Resistance (R)
What class of hard hat would provide the best protection for an electrician?
Class E (Electrical) Hard Hat
Do electrons flow in an open or a closed circuit?
Electrons flow in a closed circuit.
Open means not connected.
True/False: Electrical tape can be used to repair a damaged extension cord? Why/Why not?
False.
Under a load the insulation (jacket) of the cord will get hot. Electrical tape will actually melt because it is not of an equal material.
A battery would be an example of what type of current?
Direct Current or DC
A resistor has a resistance of 100 ohms is connected to a 12-volt battery, how much current will flow through the circuit according to Ohm's Law?
0.12 Amperes
I = V / R
Current (Amps) = Voltage (V) / Resistance (Ohms)
I = 12 / 100
I = 0.12 amperes
What type fire extinguisher should be used on an electrical fire?
Type C
Used for energized electrical equipment.
Usually made with CO2 or a dry powder. (No water)
What is a material called that does not conduct electricity?
An Insulator.
Examples:
Rubber, Glass, Oil, dry wood, even the air!
What do we call multiple conductors encased in the same jacket?
Cable
An electrical device box marked WP would mean what?
The electrical device box is rated to be weather-proof.
This is a box that would be used in an outdoor location.
A circuit has a voltage of 120 volts and a current of 10 amps. How much power is being used (in watts)?
1200 watts
P = V x I
Power (watts) = Voltage (Volts) x Current (Amps)
120 volts x 10 amps = 1200 watts
An anchor used for fall protection must be able to support how many pounds per person?
5000 pounds per employee
Think of tools, equipment, etc. You never know what you may be holding/connected to when you fall.
This type of circuit has more than one path for current to flow.
Parallel Circuit
What are the two most common types of wire construction?
Solid and stranded.
Solid- Lower resistance, less flexibility.
Stranded- Higher resistance, higher flexibility.
How much working space must be kept clear in front of an electrical panel?
The code requires a minimum of 36 inches or 3 feet.
This ensures that you have room to work!
What is the voltage if a circuit has 12 amps of current and 10 ohms of resistance?
120 Volts
V = I x R
Voltage = Current (Amps) x Resistance (Ohms)