Electrostatics conceptual question?

Question

Is the force between 2 charges q1 and q2 atrractive or repulsive when :

(1) q1q2 > 0

(2) q1q2 = 1

(3) q1q2 < 0

Answer 1

All three cases are valid.

+ X - = - (q1q2 < 0) ------>attractive
+ X + = + (q1q2 < 0) ------>repulsive
- X - = - (q1q2 < 0) ------>attractive

q1q2=1 in the following case:
Let us take charge on q1 is n1Q and charge on q2 is n2Q (where Q is 1.6 X 10^-19)
If n1Q X n2Q = 1
==> n1n2= 1/Q^2