Two-point charges are at a distance d. If the force between these two charges is F, what is the force between the charges when the distance between them is 3d?
Correct answer: B. F/9
- A. F/3
- B. F/9
- C. F/3d
- D. F/9d
Explanation
The electrostatic force is given as F = kq1q2/r². So the force between the two charges is inversely proportional to the square of the distance between the two charges. So if the distance becomes 3 times, the force becomes 1/9 times. Hence Option B is correct.F1 / F2 = (kq1q2/r2) /(kq1 q2/(3r)2F2 = F1/9
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Electrostatics describes forces between charges through Coulomb's law, electric fields and field intensity, then uses electric potential to measure energy per unit charge. Capacitors store charge and electrical energy, with capacitance depending on geometry and dielectric material, not simply on the amount of charge present.
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