Physics - Current Electricity Question with Solution | TestHub

The equivalent circuit of the given configuration can be drawn as follows:

With reference to the above diagram, the equivalent resistance of the given configuration can be calculated as follows:
$$\begin{array}{rlr}\frac{1}{R}& =\frac{1}{20\Omega }+\frac{1}{20\Omega }+\frac{1}{10\Omega }& \\ & =\frac{1}{5\Omega }& \\ & \Rightarrow & R=5\Omega \end{array}$$