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 shwon in fig.

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 '-'.