Problem

A resistance of

2\,\Omega

is connected across one gap of a meter bridge (the length of the wire is

100\text{ cm}

) and an unknown resistance, greater than

2\,\Omega

, is connected across the other gap. When these resistance are interchanged, the balance point shifts by

20\text{ cm}

. Neglecting any corrections, the unknown resistance is (JEE 2007) a.

3\,\Omega

4\,\Omega

5\,\Omega

6\,\Omega