A voltage `V_(0)` is applied to a potentiometer whose sliding constant is exacly in tne middle. A voltmeter `V` is connected between the sliding constant and one fixed end of the potentionmeter. If is assumed that the resistance of the voltmeter is not very high in comparison to the resistance of the potentiometer wire. What voltage will the voltmeter show : higher than, less than, or equal to `V_(0)//2`?

Explanation

Let `R` be the resistance of the whole potentimeter wire and `R_(V)` be the resistance of the voltmeter. Then the total resistance across section `AC` is
`R_(AC) = (R_(V)(R//2))/(R_(V) + (R//2)) = (R)/(2(1 + R//2 R_(V))) lt (R )/(2)`
The resistance of section `CB` is equal to `R//2`. So the reading of the voltmeter will be less than `V_(0)//2`.