Question

For the circuit shown, the total resistance between $\text{A}$ & $\text{B}$ is

• A. $12\Omega$
• B. $4\Omega$
• C. $6\Omega$
• D. $8\Omega$

Answer 1

The correct option is D $8\Omega$

In the diagram given in question, two resistance of $1\Omega$ at the extreme right of the circuit will not be considered because both are in open circuit, so current will not be flow through them.

So circuit become,



4 resistances $1\Omega$ and $4\Omega$ are in series and their equivalent resistance is in parallel combination with $8\Omega$.

After simplifying the circuit by successive reduction of series and parallel combination, we get,



Now, equivalent resistance between $\text{A}$ & $\text{B}$ is

$R_{eq}=2+4+2=8\Omega$

Hence, option $\left(d\right)$ is correct.