Question

Which of the following circuits represents a forward biased diode?

• A. (B), (D) and (E) only
• B. (A) and (D) only
• C. (B), (C) and (E) only
• D. (C) and (E) only

Hint:

For a diode to be forward biased, the anode must be at a higher potential than the cathode, allowing current to flow through the diode.

Answer 1

The Correct Option is C

To determine which circuits represent a forward biased diode, we need to understand the behavior of a diode in a circuit. A diode is forward biased when the anode (positive side) is connected to a higher potential than the cathode (negative side). This allows current to flow through the diode.

Let's analyze the provided options:

1. Option (B): Check if in this circuit the anode is at a higher voltage than the cathode. If so, it is forward biased.
2. Option (C): Similarly, verify if the circuit has the anode at a higher voltage for forward biasing.
3. Option (E): Again, inspect the points and voltages to confirm if the anode is positively biased compared to the cathode.

Upon evaluating the potential differences in the circuits shown in the original problem, it is clear that options (B), (C), and (E) have the diodes in a forward biased state.

Therefore, the correct answer is: (B), (C), and (E) only.

Answer 2

Step 1 — Recall the condition for forward bias:
A diode conducts only when it is forward biased, i.e., when the anode (positive side) is connected to a higher potential and the cathode (negative side) is connected to a lower potential. In this state, the potential difference across the diode reduces the barrier, allowing current to flow easily.

Step 2 — Check each circuit:
- Option (A): The anode is at a lower potential, so the diode is reverse biased.
- Option (B): The anode is connected to a higher potential than the cathode — forward biased.
- Option (C): The diode’s anode is again at a higher voltage — forward biased.
- Option (D): The polarity is opposite — reverse biased.
- Option (E): The anode remains more positive than the cathode — forward biased.

Step 3 — Conclusion:
The circuits that represent forward biased diodes are:
(B), (C), and (E).

✅ Correct Answer: (B), (C), and (E) only