Question

How to minimize the drift in the value of resistance measured using a Wheatstone bridge?

(a) by using a high precision null detector

(b) by keeping the lead wire resistances within 0.2 mΩ

(c) by using a e.m.f source of minimum value

(d) by minimizing the flow of current

The question was asked in semester exam.

I'd like to ask this question from Limitations of Wheatstone Bridge topic in division Measurement of Resistance of Electrical Measurements

Answer 1

Correct answer is (b) by keeping the lead wire resistances within 0.2 mΩ

The best I can explain: The drift in the measured value of resistance in a Wheatstone bridge can be minimized by maintaining the lead wire resistances within 0.2 mΩ. As a result, the effect of lead wire resistance gets removed in the output value of the bridge circuit.