Question

Strain gauges are resistance devices in a Wheat stone bridge configuration _________

(a) which does not require bridge completion circuitry and an excitation source

(b) which requires bridge completion circuitry and an excitation source

(c) which neither requires bridge completion circuitry nor an excitation source

(d) which requires bridge completion circuitry but does not  an excitation source

I have been asked this question in an interview.

My doubt is from General Considerations for Signal Conditioners in portion Recording System of Biomedical Instrumentation

Answer 1

Correct choice is (b) which requires bridge completion circuitry and an excitation source

Best explanation: Strain gauges are resistance devices in a Wheat stone bridge configuration which requires bridge completion circuitry and an excitation source. These devices require external voltage or current excitation. Signal conditioning part of the measurement system usually provides the excitation signals.