Question

The circuit has two oppositely connected ideal diodes in parallel. What is the current flowing in the circuit?

• A. $2.0A$
• B. $1.33A$
• C. $1.71A$
• D. $2.31A$

Answer 1

Answer: (C)

In the given circuit diode $D_1$ is forward biased and $D_2$ is reverse biased.
The resistance of $D_1$ is zero and that of $D_2$ is infinite as the diodes $D_1$ and $D_2$ are ideal. No current flows through $D_2$.
Thus $D_1$ can be replaced by a resistanceless wire and $D_2$ can be replaced by a broken wire. The equivalent circuit is shown in the figure.

The current in the circuit is
$I=\frac{12V}{4\Omega +3\Omega }$
$=\frac{12V}{7\Omega }$
$=1.71A$