Question

The equivalent resistance between A and B (of the circuit shown) is

• A. 4.5 $\Omega$
• B. 12 $\Omega$
• C. 5.4 $\Omega$
• D. 20 $\Omega$

Answer 1

Answer: (A)

$7\Omega ,3\Omega$ are in parallel and $6\Omega ,4\Omega$ are in parallel and both combinations are in series.
So, $30mm{R}_{eq}=\frac{7\times 3}{7+3}+\frac{4\times 6}{4+6}$
$\Rightarrow 30mm{R}_{eq}=\frac{21}{10}+\frac{24}{10}$
$\Rightarrow 30mm{R}_{eq}=2.1+2.4$
$\Rightarrow 30mm{R}_{eq}=4.5\Omega$