Question

$500000$joules of energy consumed by an electric heater in$500s$. If the P.D. is $200V$, find the current flowing through the heater.

Answer 1

Step 1: Given data

Consumed energy $H=500000Joules$

Potential difference $V=200V$

Time, $t=500s$

Step 2: To find out the resistance of the heater

The formula for energy consumed in a circuit is,

$H=\frac{V^2}{R}t$

$$\begin{gathered} \Rightarrow 500000=\frac{{\left(200\right)}^2}{R}\times 500 \\ \Rightarrow R=\frac{{\left(200\right)}^2}{500000}\times 500 \\ \Rightarrow R=40\Omega \end{gathered}$$

So, the resistance of the heater came out to be$R=40\Omega$.

Step 3: To find out the current flowing through the heater

According to ohm's law, $V=I.R$

So, $I=\frac{V}{R}$

$\Rightarrow I=\frac{200}{40}=5A.$

Thus, the current flowing through the heater is $5A.$