While doing an experiment with potcntiometc as shown in figure in was found that th deflection is one sided and (i) the detlectio, decreased while moving from one end A of the wire to the end B, (ii) the deflection increase while the jockey was moved towards the end

(i) Which terminal + or - ve Of the cell `E_(1) ` connected at X in case (i) and how is related to E ?
(ii) Which terminal of the cell `E_(1)` is connected at X in case (ii) ?

Explanation

(i) Deflection of galvanometer is on one side when jokey key is moved from A to B if deflection decreases, then it can be said that current through primary cell (lower circuit) decrease. and p.d. between point A and jokey key increase. This is possible only if positive of `E_(1) ` cell is connected with terminal X, thus `E_(1) gt ` E (ii) When jokey key is moved from A to B if deflection increases then it can be said that current through primary cell (lower circuit) increases and p.d. between jokey key and A decreases.
This is possible only if positive of `E_(1) ` cell is connected with X.