Question

An electric heater of power $900W$, has a resistance of $36\Omega$. Calculate the magnitude of current and the $p.d$. at its ends.

Answer 1

Step 1: Determining the magnitude of the current:

Given data :

$R=36\Omega$

$P=900W$

The value of current in the given case is,

$P=I^{2}R$

$I^2=\frac{P}{R}$

$=\frac{900}{36}$

$=25$

$=5^2$

$I=5A$

Step 2: Calculating the $p.d.$at its ends:

$V=\frac{P}{I}$

$=\frac{900}{5}$

$V=180V$

Therefore, the magnitude of current is $5A$ and the $p.d$ at its ends is$180V$ .