The equivalent resistance of the circuit shown below between points a and b is :

Question

Aicharya · Accepted Answer

The resistance in $ab$ is parallel to all other resistances. Since all the resistances other than $R_b$ is $4 \Omega$ the potential is zero $V_x = V_y$ as the upper branch will become a case of balanced wheatstone bridge between $V_x$ and $V_y$. So, the simplified circuit looks like the one below.

Hence, the equivalent resistance is $\begin{aligned} \frac{1}{R_{eq}} &= \frac{1}{8} + \frac{1}{8} + \frac{1}{16} = \frac{5}{16} \\ \Rightarrow R_{eq} &= \frac{16}{5} \Omega = 3.2 \Omega \end{aligned}$

The equivalent resistance of the circuit shown below between points a and b is :

Solution