Question

Which of the following is true about the two charged vanes that produce electric field in Paramagnetic oxygen analyzer?

(a) Both the vanes should be at higher potential than the test body

(b) Both the vanes should have the same potential as the test body

(c) One vane should be at higher potential than the test body and the other vane should be at lower potential

(d) Both the vanes should be at lower potential than the test body

The question was asked during a job interview.

My question is taken from Paramagnetic Oxygen Analyser topic in chapter Industrial Gas Analysers of Analytical Instrumentation

Answer 1

Correct answer is (c) One vane should be at higher potential than the test body and the other vane should be at lower potential

To explain I would say: In Paramagnetic oxygen analyzer, the two charged vanes should be such that one vane should be at higher potential than the test body and the other vane should be at lower potential. This electric field produces a force.