Physics 2008 JAMB Past Questions - Question 48: Zener diode is used for

Correct Answer

C

Explanation

Zener diode is useful in stabilized power supply i.e. to keep steady the voltage of power supplyZener diodes are primarily used for voltage regulation and voltage reference in electronic circuits. They are specifically designed to maintain a constant output voltage across their terminals, even when the input voltage or load conditions vary.

Here are the main purposes and applications of Zener diodes:

1. Voltage Regulation: Zener diodes can be used to regulate voltage by maintaining a constant output voltage across their terminals. When a Zener diode is properly biased in the reverse breakdown region, it will maintain a nearly constant voltage drop (known as the Zener voltage or breakdown voltage) across its terminals, regardless of changes in input voltage.

2. Voltage Clipping: Zener diodes can be used to clip voltage levels in electronic circuits. When the input voltage exceeds the Zener voltage, the diode conducts and limits the output voltage to the Zener voltage.

3. Voltage Reference: Zener diodes are often used as stable voltage references in electronic circuits. They provide a fixed voltage level that can be used as a reference for other components and circuitry.

4. Noise Suppression: Zener diodes can be used to suppress voltage spikes and noise in electronic circuits by providing a stable reference voltage.

5. Protection: Zener diodes can be used to protect sensitive electronic components from overvoltage conditions by shunting excess voltage away from the protected components.

6. Signal Clipping: Zener diodes can be used to limit the amplitude of AC signals by conducting when the signal amplitude exceeds the Zener voltage.

7. Oscillation and Waveform Clipping: Zener diodes are also used in some oscillator and waveform shaping applications to limit the amplitude of signals in a controlled manner.

Zener diodes are available in a variety of voltage ratings, making them suitable for different applications that require precise voltage control or reference. They are commonly found in power supplies, voltage regulators, and a wide range of electronic devices where stable voltage levels are essential.