1.

How can one decrease the spreading resistance in the base of the heat sink?(a) Increase the base thickness.(b) Decrease the base thickness.(c) Choosing a material with less conductivity.(d) There is no possible way.This question was addressed to me during an online interview.My question is based upon Transistor Case and Heat Sinks in section Differential and Multistage Amplifiers of Electronic Devices & Circuits

Answer»

Correct choice is (a) Increase the BASE thickness.

The BEST I can explain: Spreading resistance occurs when thermal energy is transferred from a minute area to a larger area in a SUBSTANCE with finite thermal conductivity. In a heat sink, this MEANS that heat does not distribute uniformly through the heat sink base. The spreading resistance occurrence is shown by how the heat travels from the heat source location and causes a large temperature gradient between the heat source and the edges of the heat sink. This means that some fins are at a LOWER temperature than if the heat source were uniform from corner to corner of the base of the heat sink.



Discussion

No Comment Found

Related InterviewSolutions