Answer:
According to Coulomb's law, the magnitude of electrostatic force of attraction between two point charges is directly proportional to product of magnitudes of charges and inversely proportional to the square of the distance between them.
Mathematically, F = \frac{q_{1}q_{2}}{r^{2}}
where F = force
q_{1} = charge 1
q_{2} = charge 2
r = distance between the charges
Therefore, when distance is increase by four times then the force will decrease by a factor of 16 as force is inversely proportional to the square of distance.
Explanation:
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