Question

What is the expression for the electrical power spent in flow of current through a conductor in terms of resistance and potential difference ?

• A. $V^2/R$
• B. $V/R^2$
• C. $VR$
• D. $V^{2}R$

Answer 1

The correct option is A $V^2/R$

If a certain amount of power is dissipated for a given time, then energy is dissipated. Energy ($power\times time$) is measured in Joules and by including time (t) in the power formulae, the energy dissipated by a component or circuit can be calculated.

Energy dissipated $=Pt$ or $VI\times t$ as $P=VI$. When the time factor is ignored, the relationship can be written as

$P=\frac{V^2}{R}asI=\frac{V}{R}$.

Hence, the expression for the electrical power spent in flow of current through a conductor in terms of resistance and potential difference is given as $P=\frac{V^2}{R}$.