Question

Find the net resistance between points $A$ and $B$ :

• A. $\frac{15}{2}\Omega$
• B. $15\Omega$
• C. $\frac{7}{2}\Omega$
• D. $7\Omega$

Answer 1

The correct option is A $\frac{15}{2}\Omega$


The given circuit can be redrawn as:


Here, $3\Omega$ and $6\Omega$ are in parallel with each other. Their net resistance is given by :
$R=\frac{6\times 3}{6+3}=2\Omega$

Therefore, the above circuit can be further simplified as :

Hence, the net resistance between $A$ and $B$ is :
$R_{AB}=\frac{10\times 30}{10+30}=\frac{15}{2}\Omega$