A celll of V volts and neglgible internal resistance is connected across a potentiometer Whose sliding contact is placed exactly at the middle . A voltmeter is connected between the sliding contact and one fixed end of the potentimeter . If it is assumed that the resistance of voltmeter is not very high compared with the resistance of the potentimeter , what voltage will the voltmeter show : higher than or less than `(V)/(2)` ? Justify your answer .

Explanation

B is the midpoint of the potentiometer AC

So long as the voltmeter D is not connected , `V_(AB)=V_(BC)=(V)/(2)` But as the voltemeter is connected between the points B and C the resistance of the portion BC and resistance of the voltmeter D form a parallel combination . So, the equivalent resistance of BC, i. e , in this condition the resistance of AB is graeter than resistance of between the points B and C becomes less than the resistance of BC , i.e . , in this condition the resistance of AB is greater than the resistance of BC. So `V_(AB)gtV_(BC)` i. e ., the potentail difference between A ans B will be greater than `(V)/(2)` . So , the voltmeter will record a reading less than `(V)/(2)` .