Question

Diode is used as

• A. Amplifier
• B. Oscillator
• C. Modulator
• D. Rectifier

Hint:

Think of the arrow in the diode's circuit symbol. The arrow points in the direction of conventional current flow (from the p-side/anode to the n-side/cathode). This visual cue helps to remember its function as a one-way gate for current, which is the essence of rectification.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
A semiconductor diode (typically a p-n junction diode) is a two-terminal electronic component whose fundamental characteristic is that it allows electric current to flow easily in one direction (forward bias) while severely restricting it in the opposite direction (reverse bias).
Step 2: Detailed Explanation:
This property of allowing unidirectional current flow is the key principle behind rectification.
Rectification is the process of converting alternating current (AC), which periodically reverses its direction, into direct current (DC), which flows in only one direction.
A diode, when placed in an AC circuit, acts like a one-way electrical valve. It allows either the positive or negative half-cycles of the AC waveform to pass through while blocking the other half. This converts the AC into a pulsating DC.
Step 3: Analyzing the Options:
(A) Amplifier: A device that increases the amplitude of an electrical signal. This is the primary function of a transistor.
(B) Oscillator: A circuit that produces a continuous, repeated, alternating waveform without any input. Transistors or op-amps are typically used.
(C) Modulator: A device used in communications to superimpose a message signal onto a high-frequency carrier wave.
(D) Rectifier: A device that converts AC to DC. This is the most fundamental application of a diode.
Step 4: Final Answer:
The primary and most common application of a diode is to function as a rectifier due to its ability to conduct current in only one direction. Therefore, option (D) is correct.