Question

When the temperature is increased, what happens to the collector current after a feedback is given?

(a) it remains same

(b) it increases

(c) it cannot be predicted

(d) it decreases

This question was posed to me in an online interview.

This key question is from Thermal Runaway in chapter Transistor Biasing and Thermal Stabilization of Electronic Devices & Circuits

Answer 1

The correct answer is (d) it decreases

Explanation: Before the feedback is applied, when the temperature is increased, the reverse saturation increases. The collector current also increases. When the feedback is applied, the base current increases with decreasing collector current and the thermal runway too.