Question

The equivalent resistance between $A$ and $B$ (of the circuit as shown in figure) is

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

Answer 1

The correct option is A $4.5\Omega$

Equivalent circuit can be redrawn as:


Resistor $7\Omega$ and $3\Omega$ are in parallel;
$6\Omega$ and $4\Omega$ are in parallel and their equivalent are in series.

So, $R_{eq}=\frac{7\times 3}{7+3}+\frac{4\times 6}{4+6}=4.5\Omega$