Question

An electric kettle draws a current of $4A$ for $2.5min$. If the resistance of its element is $100\Omega$, calculate the electric energy drawn by kettle in kilojoules.

Answer 1

Hint:

$w=I^{2}Rt$

$w=$Energy

$R=$Resistance

$t=$Time

Step 1:

Find the electric energy is drawn by the kettle in kilojoules

Given data :

$I=4A$

$R=100\Omega$

$t=2.5min$

Electric energy is drawn $𝑤=I^2𝑅𝑡$

$W=4\times 4\times 100\times \left(\frac{25}{10}\times 60\right)$

$=1600\times \left(\frac{25}{10}\times 60\right)$

$=1600\times 25\times 6$

$=1600\times 150$

$=240000𝐽$

Divide the energy value by $1000$

$W=\frac{24000}{1000}$

$=240kJ$

The electric energy is drawn by the kettle in kilojoules is $240kJ$