Question

Which of the following technique is not employed in isolation devices?

(a) resistance

(b) optical

(c) inductance

(d) capacitance

The question was posed to me by my school principal while I was bunking the class.

The origin of the question is General Considerations for Signal Conditioners in portion Recording System of Biomedical Instrumentation

Answer 1

Right option is (a) resistance

To elaborate: Resistance technique is not employed in making isolation devices. The isolation devices pass the signal from its source to the measurement device without a physical or galvanic connection by using transformer, optical or capacitive coupling technique.