Two point charges of 20 μC and 80μC are 10 cm apart. Where will the electric field strength be zero on the line joining the charges ?

Let the electric field strength will be zero at a distance x. Then 14πε0×20×10−6x2=14πε0×80×10−6(10−x)2 or (10−x)2x2=4 or 10−xx=±2This gives x = - 10 cm or 3 . 33 cm i.e., 0.033 m