Question

what will be force between two electrons if distance is increased 4 times? (use Columbus law)

Answer 1

We know,
Columb's Law :-
Force is inversely proportional to square of distance between them.
e.g F = P/r² -------(1)
Where P is constant.

Let initial Force = F
Now distance between two charge increased 4times.
e.g R = 4r

F' = P/(4r)² = P/16r² = (1/16) P/r²

But P/r² = F according to equation (1)
So,
F' = F/16

Hence Force will be reduce 16 times of initial force.