Experiment Description

Experiment

Experiment E21    Transistor as a Linear Voltage Amplifier

Objectives
  • Obtain the input/output voltage characteristics of a transistor module
  • Set biasing condition for a linear voltage amplifier
  • Study how a transistor can be used to amplify an a.c. signal
  • Estimate the current amplification factor of a transistor from the voltage gain
Description
In this activity, you will construct a linear amplifier using a transistor. A.c. from a signal is amplified and displayed on a double beam CRO.

In Experiment 1, you will study the input/output characteristics of a transistor. The input voltage is provided by a potential divider and recorded by the voltmeter on the left. The output voltage is recorded by the voltmeter on the right.

In Experiment 2, you will demonstrate the amplification of an a.c. source using the transistor. You will calculate the voltage gain of the amplifier. You will also deliberately produce distorted output.
Apparatus
n-p-n transistor [1]
resistor (15 kOhm) (base resistor) [1]
resistor (1 kOhm) (load resistor) [1]
capacitor (10 mF) [2]
variable resistor (0 - 5 kOhm) [1]
voltmeter (1V, 5 V and 10 V) [1]
signal generator [1]
double beam CRO [1]
battery box with 4 dry cells [1]
Experiment