Electrical Technology

E = I*R
E = Voltage
I = Current
R = Resistance
If there is 15 Amps of current flowing through 20 Ohms of resistance, what would the voltage be in this circuit?

• 15/20 = 3/4 = 0.75 Volts
• 15 * 20 = 300V
• 15/20 = 3/4V
• 15 * 20 = 3000 Volts

E = IR
E = Voltage
I = Current
R = Resistance
If a circuit has a voltage of 120 Volts and a current flow of 20 Amps,  what is the resistance?

• 120/20 = 6 Ohms
• 15 * 20 = 300 Volts
• 120 * 20 = 2400 Ohms
• 120/20 = 6 Amps

What is the first step to solving the problem:
If 277 Volts flows through a 25 Ohms of reisistance, what is the amount of current in this circuit?

• Rearrange the equation to get the variable for current by itself.
• Rearrange the equation so the variable for current is on the left-hand side, with Energy.
• Plug in the numbers and chug it out.
• Combine like terms.

VD = (2K*L*I)/(CM)
VD = Voltage Drop
K = A constant multiplier for the type of wire 12.9 for Copper and 21.2 for Aluminum
L = Length of the wire
I = The current rating of the system
CM = Circular Mills of the wire
What is the voltage drop of a 277V 50A system traveling 950ft utilizing a number 10 AWG copper conductor (CM = 10,380)?

• 122550/10380
• 12.25V
• ~= 12V
• 11.8V

VD = (2K*L*I)/(CM)
K = A constant multiplier 12.9 for Copper and 21.2 for Aluminum
What is the voltage drop of a 277V 50A system traveling 950ft utilizing a number 8 AWG aluminum (CM = 16,510)?

• 12.2V
• 122V
• IDK/IDC
• 122A