Question

Which of the following is the principle behind strain gauge?

(a) variable contact area

(b) variable inductance

(c) variable capacitance

(d) variable resistance

This question was posed to me by my school teacher while I was bunking the class.

I'm obligated to ask this question of Implantable Telemetry Systems topic in division Biomedical Telemetry of Biomedical Instrumentation

Answer 1

Correct option is (d) variable resistance

To elaborate: The principle behind strain gaude is the variable resistance. A linear relation exists between the deformation and electrical resistance of a suitable selected gauge over a specified range. The transducer is based upon the changed in resistance of a wire produced due to small mechanical displacement.