Question

Gauge factor is given by which of the following relation?

(a) S = \(\frac{\Delta R/R}{\Delta l}\)

(b) S = \(\frac{\Delta R}{\Delta l/l}\)

(c) S = \(\frac{R}{\Delta l/l}\)

(d) S = \(\frac{\Delta R/R}{\Delta l/l}\)

I had been asked this question during an interview.

I'm obligated to ask this question of Operation of Strain Gauges topic in section Transducers of Electrical Measurements

Answer 1

The correct option is (d) S = \(\frac{\Delta R/R}{\Delta l/l}\)

The explanation: Gauge factor in a strain gauge is given by the relation

S = \(\frac{\Delta R/R}{\Delta l/l}\)

where, S is the gauge factor

       R is the gauge wire resistance

            ∆R is the change in resistance

       l is the length of the wire in unstressed condition

            ∆l is the change in length of the wire.