In the given figure of meter bridge experiment, the balancing length A C corresponding to null deflection of the galvanometer is 40 cm . The balancing length, if the radius of the wire A B is doubled, will be _____ cm .

Step-by-step solution

Even if the radius of wire is doubled, the balancing point would not change as x l - x = R 1 R 2 , which is independent of area in case of uniform wire. Thus, the balancing length remains the same i.e., 40   cm .