Task id16242

In Fig. shows a bridge for measuring resistance (Wheatstone bridge). Unknown resistance Rx, R0 is the reference resistance. The voltmeter is connected by a sliding contact to a homogeneous high resistance wire AB (reohord). The distance of contact D from points A and B can be measured using a centimeter, which lies next to the high-resistance resistance AB. At the moment when the voltmeter readings are equal to zero, the distances l1 and l2 are recorded. Determine the unknown resistance Rx.