Question

If the differential amplifier gives a negative output then it infers which of the following (Reference output is given to the positive terminal and sample output is given to the negative terminal)?

(a) The concentration of silica in sample and reference solution is equal

(b) The concentration of silica in a reference solution is more than that in the sample solution

(c) The concentration of silica in sample solution is more than that in the reference solution

(d) Further processing is required to come to any conclusion

The question was posed to me in examination.

I need to ask this question from Silica Analyser in section Dissolved Component Analysers of Analytical Instrumentation

Answer 1

Correct option is (b) The concentration of silica in a reference solution is more than that in the sample solution

To explain: If the differential amplifier gives a negative output then, it means that the concentration of silica in a reference solution is more than that in the sample solution. It means that the photodetector’s output is not equal.