Question

An electric kettle draws a current of $5A$ for $5minutes$. If the resistance of its element is $80\Omega$, calculate the electric energy drawn by the kettle in kilojoules.

Answer 1

Step 1: Given data and formula

Given data:

1. Current drawn by electric kettle is $I=5A$
2. Time for which current flows is $t=5minutes=5\times 60=300s$ (Note: $1min=60sec$)
3. Resistance of the element is $R=80\Omega$

Formula:

Electric energy drawn by the kettle is equal to the heat produced by the kettle.

Therefore, the amount of heat produced $\left(H\right)$ by an electric kettle is given by

$H=I^{2}Rt$

Step 2: Finding the amount of heat produced or electric energy drawn by the kettle

Substituting the values of current, resistance, and time into the formula to calculate the amount of heat produced.

$$\begin{gathered} H={\left(5A\right)}^2\left(80\Omega \right)\left(300s\right) \\ H=25\times 80\times 300 \\ H=600000(1kJ=1000J) \\ H=600kJ \end{gathered}$$

Thus, the electric energy drawn by the kettle is $600kJ$.