Question

Three resistors are connected to a 6 V battery as shown in the figure given.

Calculate the potential difference across the $7.2\Omega$ resistor.

Answer 1

In this circuit, $8\Omega$ and $12\Omega$ are connected in parallel, and this parallel resistors are connected in series with $7.2\Omega$.

$8\Omega$ and $12\Omega$ are in parallel, their equivalent resistance:

$\frac{1}{R}=\frac{1}{8}+\frac{1}{12}=\frac{5}{24}$

$R=4.8\Omega$

Now, Equivalent resistance (series connection) of the circuit $=4.8+7.2=12\Omega$

$V=I{R}_{eq}$

$I=\frac{V}{R_{eq}}=\frac{6}{12}=0.5A$

Potential Difference across $7.2\Omega$ resistor $=I\times R=0.5\times 7.2=3.6V$