Question

Thirteen resistance each of resistance $Rohm$ are connected in the circuit as shown in the figure below. The effective resistance between $A$ and $B$ is

• A. $2R\Omega$
• B. $\frac{4R}{3}\Omega$
• C. $\frac{2R}{3}\Omega$
• D. $R\Omega$

Answer 1

The correct option is C $\frac{2R}{3}\Omega$

We draw the equivalent circuit

For series $R_{eq}=\frac{2R}{3}+\frac{2R}{3}=\frac{4R}{3}\Omega$

For parallel $R_{eq}=\frac{1}{\frac{3}{4R}+\frac{3}{4R}}=\frac{2R}{3}\Omega$

Hence, $R_{eq}=\frac{2R}{3}\Omega$