Question

Buffer amplifier converts ____________

(a) low impedance signals to high impedance signals

(b) high impedance signals to low impedance signals

(c) ac impedance signals to dc impedance signals

(d) dc impedance signals to ac impedance signals

The question was posed to me during an interview.

I need to ask this question from Electrodes for ECG in section Bioelectric Signal and Electrodes of Biomedical Instrumentation

Answer 1

Right option is (b) high impedance signals to low impedance signals

The best I can explain: Noise is typically generated from motion artefacts and power line interference. A common solution used to suppress noise in dry electrode signals is a buffer amplifier. A  buffer amplifies is essentially an impedance converter, that converts high impedance signals to low impedance signals.