Physics – 4.3.1 Circuit diagrams and circuit components | e-Consult

(a)

The circuit diagram with the LED in reverse bias is as follows:

[Image missing: LED in Reverse Bias Diagram]

(b) When the LED is reverse biased, the diode blocks the current. Therefore, no current flows through the LED, and it does not light up. The diode prevents the current from flowing in the reverse direction, protecting the LED from damage.

(c) To ensure the LED only lights up with the correct polarity, the diode must be connected in series with the LED. This is already the case in the original circuit diagram. The diode acts as a one-way valve, allowing current to flow only when the battery is connected in the correct direction (forward bias). If the battery is connected in the reverse direction, the diode blocks the current, and the LED remains unlit.