Question

The figure shows two diagrams in which diode and resistance are connected. Out of the following statements which one is TRUE?

• A. Diagram (a) and diagram (b) both are forward biased
• B. Diagram (a) forward biased and diagram (b) reverse biased
• C. Diagram (a) and diagram (b) both are reverse biased
• D. Diagram (a) reverse biased and diagram (b) forward biased

Hint:

To check diode biasing, always compare anode and cathode potentials instead of absolute values.

Answer 1

The Correct Option is D

Step 1: Condition for forward and reverse bias.
A diode is forward biased when anode is at higher potential than cathode and reverse biased otherwise.

Step 2: Analysis of diagram (a).
In diagram (a), anode is at $-4\,V$ and cathode is at $-3\,V$.
Since anode is at lower potential, the diode is reverse biased.

Step 3: Analysis of diagram (b).
In diagram (b), anode is at $0\,V$ and cathode is at $-2\,V$.
Since anode is at higher potential, the diode is forward biased.

Step 4: Conclusion.
Diagram (a) is reverse biased and diagram (b) is forward biased.