Two point-like charge a and b whose strengths are equal in absolute value are positioned at a certain distance from each other. Assumeing the field strenght is positive in he direction of the r axis. Determine the sign of the charge for each distribution of the field strenght between charge for each distribution of the field strenght between charges src="https://d10lpgp6xz60nq.cloudfront.net/physics_images/BMS_V03_C01_E01_055_Q01.png" width="80%">

Explanation

(a) As electric fild tends away at a and towards at b, there should be positive charge at a and negative charge at b, i.e., `q_(a)` is '+' and `q_(b)` is '-'.
(b) The neutral point exists between a and b only when both `q_(a)` and `q_(b)` are of same sign. As direction of electric field is away from both, both charges are positive, i.e., `q_(a)` is '+' and `q_(b)` is '+'
(c ) `q_(a)` is '-' and `q_(b)` is '+'`.
(d) `q_(a)` is '-' and `q_(b)` is '-'.