Four identical resistive strain gauges with gauge factor of 2.0 are used in a Wheatstone bridge as

Q. Four identical resistive strain gauges with gauge factor of 2.0 are used in a Wheatstone bridge as shown in the figure below. Only one of the strain gauges 𝑅_{𝑆𝐸𝑁𝑆𝐸} changes its resistance due to strain. If the output voltage 𝑉_𝑂𝑈𝑇 is measured to be 1 mV, the magnitude of strain, in units of microstrain, is

(A) 1

(B) 10

(C) 10

 (D) 1000

Ans: 1000

Sol:

Given that, gauge factor (Gf) = 2. Output voltage (Vo) = 1 mV Source voltage (Vs) = 2 V For the given bridge, output voltage is given by