Two wires A and B of equal lengths are connected in left and right gap of a metre bridge, null point is obtained at 40 ~cm from left end. Diameters of the wires A and B are in the ratio 3: 1 . The ratio of specific resistance of A to that o

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Two wires A and B of equal lengths are connected in left and right gap of a metre bridge, null point is obtained at 40 ~cm from left end. Diameters of the wires A and B are in the ratio 3: 1 . The ratio of specific resistance of A to that of B is

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Correct answer: B. 6:1

aligned _ A &= _ B r_ A r_ B = 3 1 R_ A R_ B &= 4 6 = 2 3 = _ A _ B A_ A A_ B _ B _ B &= _ A _ B _ A _ B r_ B ² r_ A ² _ A _ B &= 2 3 9= 6 1 aligned

Two wires A and B of equal lengths are connected in left and right gap of a metre bridge, null point is obtained at 40 ~cm from left end. Diameters of the wires A and B are in the ratio 3: 1 . The ratio of specific resistance of A to that of B is

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