Question

When the current and resistance is given in an electric circuit, power can be calculated by:

• A. multiplying the current by the current and the resistance
• B. multiplying the resistance by the resistance and the current
• C. multiplying the current by the difference between the voltage going into and going out of the device
• D. multiplying the resistance by the difference between the voltage going into and going out of the device
• E. multiplying the voltage by the voltage and the current

Answer 1

The correct option is A multiplying the current by the current and the resistance

Power $P=V\times I$ where $V$ is the voltage of the battery

Using $V=IR$

$⟹$ $P=\left(IR\right)\times I=I^{2}R$

Thus option A is correct.