Question

Which of the following are true?

(a) TJ-TA=θpd

(b) TJ-TA=θ/pd

(c) TJ-TA=θ+pd

(d) TJ-TA=θ-pd

The question was posed to me in unit test.

I want to ask this question from Thermal Stability in division Transistor Biasing and Thermal Stabilization of Electronic Devices & Circuits

Answer 1

Correct choice is (a) TJ-TA=θpd

To elaborate: The TJ¬ is called as junction temperature which varies and TA is called as the ambient temperature which is fixed. The difference between these temperatures is directly proportional to the power dissipation. Here, θ is called as thermal resistance which is proportionality constant.