In a meter-bridge experiment with a resistance `R_(1)` in left gap and a resistance `X` in a right gap. null point is obtained at `40 cm` from the left emf. With a resistance `R_(2)` in the left gap, the null point is obtainned at `50 cm` from left hand. Find the position of the left gap is containing `R_(1)` and `R_(2)` (i) in series and (ii) in parallel.

Answer

62.5cm