Two point charges placed in vacuum repel each other with a force of . If they are placed at the same separation in a dielectric medium of dielectric constant , what is the new electrostatic force?
Answer and explanation
Correct answer: D.
- Step 1: According to Coulomb's law, the electrostatic force between two point charges in a medium of dielectric constant is given by .
- Step 2: Substitute : .
Answer
.
Why not the others: incorrectly multiplies by the dielectric constant rather than dividing; uses the square root of ; and squares the dielectric constant.
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