Question

How is the contact resistance related to the circuit while measuring a low resistance?

(a) independent of the type of resistance

(b) it is negligible

(c) depends on the e.m.f source

(d) it is very high

The question was asked in a job interview.

This question is from Measurement of Low Resistance topic in section Measurement of Resistance of Electrical Measurements

Answer 1

Correct choice is (b) it is negligible

To explain: The contact and lead resistances form a part of the circuit whose resistance is very high.  As a result the contact and lead resistances are usually neglected compared to the high resistance value.