Question

what is the nature of electrostatic force between two charges q1 and q2 when
1.q1+q2>0
2.q1+q2<0

Answer 1

1) q1 + q2 > 0
here two case possible ,

case 1 :-
q1 > 0 and q2 >0 then, q1 + q2 >0
then, force is repulsive becoz both have same nature of charge e.g positive

case 2 :-
q1 >0 , q2 < 0 but | q1 | > | q2 |
then, also q1 + q2 > 0
then, force will be attractive , becoz opposite nature of charge .

2) q1 + q2 < 0
here also , two case possibe

case 1 :-
q1 < 0 and q2 < 0 then, q1 + q2 < 0
then force will be repulsive

case 2 :-
q1 > 0 , q2 < 0 and | q1 | < | q2 |
then, q1 + q2 < 0
then force will be attractive