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Electric Charges And Fields

Question

Two point charges + 8q and – 2q are located at x = 0 and x = L respectively. The location of a point on the x axis at which the net electric field due to these two point charges is zero is

2L

L/4

8L

4L

Solution

fraction numerator straight k 2 straight q over denominator left parenthesis straight x minus straight L right parenthesis squared end fraction plus fraction numerator straight k 8 straight q over denominator straight x squared end fraction space equals space 0 space rightwards double arrow space straight x space equals 2 straight L