Q. A resistance of 2 W is connected across one gap of a meter-bridge (the length of the wire is 100 cm) and an unknown resistance, greater than 2W, is connected across the other gap. When the resistances are interchanged, the balance point shifts by 20 cm. the unknown resistance is?

1. 3Ω
2. 4Ω
3. 6Ω
4. 5Ω