Question

Thirteen resistances each of resistance $R \, \Omega$ are connected in the circuit, as shown in the figure. The effective resistance between $A$ and $B$ is

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

Answer 1

Answer: (C)

From symmetry, we get the following circuit diagram for half circuit,

For half circuit, $R^{′}=\frac{R}{3}$ .
$R_{e q}=\frac{2 R}{3}$