Question

A metallic wire of resistance R is cut into 10 parts of equal length two pieces each are joined in series and then five such combinations are joined in parallel what will be the effective resistance of the combination

Answer 1

The resistance of a conductor is directly proportional to the length of the conductor. The resistance of the metallic wire ,when it is cut into ten equal parts of equal length is ,r=R÷10, 2 such pieces when joined in series ,the equivalent resistance of these two parts =r+r=2r=2R÷10. series resistance of 2 parts =2×R÷10=R÷5, 5such elements are connected in parallel.therefore the total resistance R1will be 1÷R1=R÷25.