Physics – 4.3.1 Circuit diagrams and circuit components | e-Consult
4.3.1 Circuit diagrams and circuit components (1 questions)
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(a) The diode acts as a one-way valve for electrical current. It allows current to flow easily in one direction (forward bias) but blocks current flow in the opposite direction (reverse bias). In this circuit, the diode ensures that current only flows through the LED when the battery is connected in the correct polarity. This prevents the LED from being damaged by reverse voltage.
(b) Power (P) can be calculated using the formula P = V * I. In this case, V = 2V and I = 0.02A (20mA = 0.02A). Therefore, P = 2V * 0.02A = 0.04W. The power dissipated by the LED is 0.04 Watts.
(c)
- Advantage: The diode protects the LED from damage due to reverse polarity connection. Without the diode, reversing the battery could permanently damage the LED.
- Disadvantage: The diode introduces a voltage drop of approximately 0.7V (for silicon diodes). This reduces the amount of voltage available to the LED, potentially making it dimmer than if it were connected directly to the battery.