Answer:
P = (120)² / R
Explanation:
Electrical power (P) is equal to the voltage (V) times the current (I). From Ohm's law, the voltage drop (V) across a resistor is equal to the current (I) times the resistance (R). Substituting, we can show that the power is equal to the square of the voltage divided by the resistance.
Starting with Ohm's law:
V = IR
Solving for current:
I = V/R
Definition of power:
P = VI
Substituting:
P = V (V/R)
P = V²/R
If the voltage is 120 V, then the power is:
P = (120)² / R