Question

What is the effect of lead wires on the Wheatstone bridge?

(a) no effect

(b) stabilizes the system

(c) desensitizes the system

(d) increases the resistance of the circuit

This question was posed to me in an interview for internship.

This key question is from Limitations of Wheatstone Bridge topic in section Measurement of Resistance of Electrical Measurements

Answer 1

Correct option is (c) desensitizes the system

To elaborate: The lead wires connecting the resistance arms of a Wheatstone bridge add to the existing values of resistances across the ratio arms. As a result the net value of resistance changes, thus destabilizing the system.