Question

What is a transistor? By drawing the circuit diagram of common emitter configuration, plot the output characteristics.

Hint:

The common emitter configuration provides voltage amplification and is widely used in signal amplification.

Answer 1

A **transistor** is a semiconductor device used to amplify or switch electronic signals and electrical power. It consists of three layers of semiconductor material, known as the emitter, base, and collector. The common emitter configuration is the most commonly used configuration in amplifiers. It has the following characteristics: - The emitter is common to both the input and output. - The base controls the current between the collector and emitter. - It provides high voltage gain. ### Circuit Diagram of Common Emitter Configuration: \[ \text{[Insert diagram of common emitter configuration here]} \] ### Output Characteristics: In the common emitter configuration, the output characteristics are a plot of collector current (\(I_C\)) versus collector-emitter voltage (\(V_{CE}\)) for different values of base current (\(I_B\)). The graph typically shows three regions: 1. **Cutoff region**: Where \(I_C = 0\). 2. **Active region**: Where \(I_C\) increases linearly with \(V_{CE}\). 3. **Saturation region**: Where the collector current becomes almost constant, irrespective of further increases in \(V_{CE}\). The graph demonstrates the transistor's ability to amplify the input signal.