In a transistor, which part is associated with the voltage output?

In a transistor, which part is associated with the voltage output?

• A. Base
• B. Collector
• C. Emitter
• D. Gate

Answer: (C)

In an emitter-follower arrangement (common-collector), the output voltage is taken from the emitter. The base receives the input signal, and the emitter voltage follows the base voltage minus about 0.7 V for a silicon transistor. This makes the emitter the node where the output voltage appears. The collector typically ties to the supply in this setup and isn’t the output node in this configuration, and the gate is the input control for a FET, not the BJT’s output terminal. So the emitter is the part associated with the voltage output.

In an emitter-follower arrangement (common-collector), the output voltage is taken from the emitter. The base receives the input signal, and the emitter voltage follows the base voltage minus about 0.7 V for a silicon transistor. This makes the emitter the node where the output voltage appears. The collector typically ties to the supply in this setup and isn’t the output node in this configuration, and the gate is the input control for a FET, not the BJT’s output terminal. So the emitter is the part associated with the voltage output.