While doing an experiment with potentiometer (Fig 3.5) it was found that the deflection is one sided and (i) the deflection decreased while moving from one end A of the wire to the end B; (ii) the deflection increased. While the jockey was moved towards the end B.
(i) Which terminal +or –ve of the cell E1, is connected at X in case (i) and how is E1 related to E?
(ii) Which terminal of the cell E1 is connected at X in case (ii)?
(i) In case (i), the deflection decreases, magnitude of current in the wire decreases and potential difference across A and jockey decreases. The deflection is one sided. This is only possible if positive terminal of E1 is connected at X and E1>E.
(ii) In case (i), the deflection increases, magnitude of current in the wire increases and potential difference across A and jockey increases. This implies, negative terminal of E1 is connected at X.