Question

An expression for the electrical energy spent in flow of current through an electrical appliance in terms of current, resistance and time is :

• A. $I^{2}Rt$
• B. $IRt$
• C. $I{R}^{2}t$
• D. $I{R}^2{t}^2$

Answer 1

The correct option is A $I^{2}Rt$

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 $VI\times tasP=VI$.
It can also be written as $\frac{V^2}{R}\times tasI=\frac{V}{R}or{I}^{2}R\times tasV=IR$.
Hence, the expression is given as $P=\frac{V^{2}t}{R}orP=I^{2}Rt$.