Concept:Interchanging the cell
E and galvanometer
G in a metre bridge does not alter the balance point, but away from balance, the deflection direction can be either left or right.
Formula:For a metre bridge at balance:
SR​=100−ll​, where
l is the balancing length. This relation is independent of which arm contains the cell or galvanometer.
Solution:When
E and
G are interchanged, the bridge circuit remains topologically the same, so the null point (balance length) does not change.
At the exact balance point, no current flows through
G, giving zero deflection.
Away from balance, the direction of deflection (left or right) depends on whether the jockey is on one side or the other of the null point.
Because the positions of
E and
G swap, the sense of the deflection can be either left-sided or right-sided depending on the jockey position.
Thus, both left and right deflections are possible when the jockey is moved, and at the balance point, no deflection occurs.
Answer:D. Both right-sided and left-sided deflection and at balance point, no deflection
