A Strain Gauge with gauge factor of 2 is fastened to a metallic member subjected to a stress of 1000 $kg/cm^2$. The modulus of elasticity of the metal is $2 × 10^6 kg/cm^3$. Calculate the percentage change in the resistance of the strain gauge. What is the value of Poisson’s ratio?

Mumbai University > Electronics Engineering > Sem3 > Electronic Instruments and Measurements

Marks: 5M

Year: Dec 2013

Given –

Gauge Factor $G_f$=2

Stress =$1000 kg/cm^2 $

Modulus of elasticity=ε= $2×10^6 kg/cm^3$

Formulae –

Modulus of elasticity=ε=Stress/Strain

Change in Resistance=$∆R=G_f×Strain$

Poisson^' sratio=$μ=\frac{G_f-1}2$

Solution –

Before we calculate the change in resistance, we have to deduce the value of strain. Strain is given by the ratio of stress and …