Question Detail

PHY 102 Coulomb's law and Electric Fields Objective Question
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Question

If the electrostatic force between two point charges in vacuum is F, and they are then placed in a large vat of water (dielectric constant K ≈ 80) while keeping their charges and separation distance the same, what would be the approximate force between them?
Options
A <i>F</i> (remains the same)
B 80 * <i>F</i> (increases by a factor of 80)
C <i>F</i> / 80 (decreases by a factor of 80)
Correct Answer
D <i>F</i> + 80 (increases by 80 N)
Correct Answer

Option C is the correct answer.

Detailed Explanation

Page 2 explains that when a material has a dielectric constant K, ε₀ in Coulomb's Law must be replaced by Kε₀. This means the force in the medium (Fmedium) is given by Fmedium = Fvacuum / K. Therefore, the force decreases by a factor of K, becoming F / 80.

Hint

How does the dielectric constant of a medium affect the electrostatic force compared to a vacuum? Refer to Eq. (24.4) and the explanation preceding it on page 2.

Question Info

Course: PHY 102
Topic: Coulomb's law and Electric Fields
Type: Objective
Difficulty: Not specified
Question 843 of 1819
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