Answer:
Choice A. P = I² · R where
- P is the power in the DC circuit,
- I is the current through the circuit, and
- R is the total resistance of the circuit.
Step-by-step explanation:
Electrical power is the rate at which the electrical force does work. So what is electrical work? That's the work that the electrical force do when it moves charges
across a potential difference
:
W = .
The power is the rate at which the electrical force do the work:
.
On the other hand, current is the charge through a cross-section of the circuit in unit time. By the definition of current:
.
.
Consider Ohm's Law:
.
Therefore
.