Question

Two point charge of +16 and -9 are placed 8cm apart in air.determine the position of the point at which the resultant electric field is zero.

Answer 1

on the side of the -9 away from the +16

let d = distance from -9

16 (d + 8)^2 = 9 d^2

Answer 2

24cm from right

Answer 3

(16/9)^1/2=d/8-d --(1)
(+,-)4/3=d/8-d
case 1 (+)
32-4d=3d
32/7=d
which is not possible as it is betweeen the two points of opposite charges resulting in repulsions
case 2 (-)
-32 +4d=3d
d=32
hence 32cm towards right