Question

An electric heater draws a current of $10A$ and its element has a resistance $20\Omega$. If the heater is switched on for 6 minutes, calculate energy released in kilojoules.

• A. $200kJ$
• B. $360kJ$
• C. $720kJ$
• D. $2kJ$

Answer 1

The correct option is C $720kJ$

Given:

$I=10A$

$R=20\Omega$

$t=6min=6\times 60s=360s$

By Joule's law of heating,
Energy released $H$

$=I^{2}Rt$

$={\left(10\right)}^2\times 20\times 360$

$=720,000J$

$=720kJ$.