Question

How does emitter resistor RE provides stability?

(a) Consumes less power

(b) Has an easier circuit design

(c) Automatically biases the circuit

(d) It does not provide stability

This question was posed to me in unit test.

This is a very interesting question from Collector-Emitter Feedback Bias topic in portion Transistor Biasing and Thermal Stabilization of Electronic Devices & Circuits

Answer 1

The correct answer is (c) Automatically biases the circuit

Best explanation: In a collector emitter feedback, the emitter resistor provides stability by automatically biasing the circuit using negative feedback. The negative feedback negates any change due to the collector current with an opposing change provided by the base bias voltage and thus helps maintain circuit stability.