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Wheatstone Bridge, , , , For a balanced Wheatstone’s bridge , the resistors are such that the current, through th galvanometer I, = 0., , Apply Kirchhoff’s junction rule to junctions B, I, = ly -------------(1), Apply Kirchhoff’s junction rule to junctions D, 1, = 3 -------------(2), Apply Kirchhoff’s loop rule to closed loop ABDA, -I,R2+ 1, Ry=0, I, Ry= 1,R2----------------(3), , Apply Kirchhoff’s loop rule to closed loop CBDC, 1,R4 — 1, R3=0, , , , eq (3) Ri _ IR, , eq (4) IgR3 14Rq, , Ri _ Re, Ry Ry, Rz _ Ry, Ri Rs, , This is the balance condition for the galvanometer to give zero or null, deflection.