AP and TS EAMCET Medical Model Paper 6

An unknown resistance R‌1 is connected in series with a resistance of 10Ω . This combination is connected in left gap of a metre bridge and A resistance R‌2 is connected in the right gap. The balance point is at 50cm. Now, when the 10Ω resistance is removed, the balance point shifts by 10cm. The value of R‌1 is