n-p-n transistor power amplifier in C-E configuration gives:

The base-emitter junction serves as the input junction and the collector-emitter junction serves as the output junction when a transistor is utilized as an amplifier in the common emitter mode. Applying forward voltage makes the input junction forward biased, and applying reverse voltage makes the output junction reverse biased.

Because the CE design offers significant current gain, voltage gain, and power gain values, we frequently use transistors in this configuration as amplifiers.