Question

How much energy is transferred when $10A$ current flows through a resistor of resistance $5\Omega$ for time of $30minutes$?

• A. 1.2 kWh
• B. 0.25 kWh
• C. 3.2 kWh
• D. 0.025 kWh

Answer 1

The correct option is B

0.25 kWh

Given:
Current, $I=10A$
Resistance, $R=5\Omega$
Time for which the current flows,
$t=30minutes=0.5h$

According to fomula for power,
$P=I^{2}R$
$P={10}^2\times 5W$
$P=500W$

Power is the rate at which energy is consumed. Hence,
$E=Pt$
$E=500\times 0.5Wh$
$E=0.25kWh$