Question

Why is attraction a not foolproof wayof testing a charge

Answer 1

okay, lets say we have a charge with us and we need to know if that is positive or negative. let that be A.

on the other hand we also do have another charge whose charge we do know. For instance lets say it is negative. and let that be B.

Now, take B towards A.

There may be 2 possibilities. Either they may attract or repel.

1. attraction: So say that they get attracted. B is negative( we know this) so then A might be POSITIVE also.. there is a chance of being it a NEUTRAL one.
see, this is where we get stuck when we use attraction.

2.Repulsion : now if the charge gets repelled it is cent percent sure that the A can only be negative. none of the other way could we think of where B can repel A other than being negative.

So, hope u got this. repulsion is the best way to see this through

Answer 2

Explanation:

attraction and repulsion both