Physics - Current Electricity Question with Solution | TestHub

In the first circuit diagram, the diodes $D_1\&D_3$ are forward biased and $D_2$ is reverse biased(Hence, no current through it). So the circuit is simplified to the second diagram.

Hence, the equivalent resistance is

$R_{eq}=\frac{20\times 10}{20+10}$

$\Rightarrow R_{eq}=\frac{20}{3}\Omega$

Using Ohm's law, the current is

$I=\frac{10}{\frac{20}{3}}=\frac{30}{20}\text{A}=1.5\text{A}$