Question

Lower resistances are difficult to measure using Wheatstone bridge circuit because of ____________

(a) Leakage currents

(b) I^2R effects

(c) Power dissipation

(d) Thermal breakdown

This question was posed to me during an interview.

I need to ask this question from Measuring Resistance the Wheatstone Bridge and Delta-to-Wye (Pi-to-Tee) Equivalent Circuits topic in division Simple Resistive Circuits of Electric Circuits

Answer 1

Correct answer is (b) I^2R effects

The best I can explain: A standard Wheatstone bridge couldn’t measure lower resistances because of thermoelectric voltages which are generated at the junctions of the dissimilar metals and also because of thermal heating effects- that is, i^2R effects.