According to Coulomb's Law, if the distance between two point charges is doubled, what happens to the electrostatic force between them?

Answer and explanation

Correct answer: D. It decreases to 1/4 of its initial value

  1. Step 1: Coulomb's Law states that electrostatic force is inversely proportional to the square of separation: F proportional to 1 / r^2.
  2. Step 2: When r is replaced by 2r, the new force becomes F_new = F / (2)^2 = F / 4.
Answer
It decreases to 1/4 of its initial value.
Why not the others: 'It decreases to 1/2 of its initial value' assumes an inverse linear relation 1/r; 'It doubles' assumes direct proportionality; 'It quadruples' assumes direct square proportionality.

Practise more Mechanics, Waves and Electromagnetism.

Free questions with an explanation for every one, and full timed Tawjihiya Bahrain (Secondary School Certificate) mock tests.

All Mechanics, Waves and Electromagnetism questionsTake a mock test

More Mechanics, Waves and Electromagnetism questions