The force between two point charges placed in air is F. If air is replaced by a medium of relative permittivity εr, the force is reduced to
Correct answer: C. F/εr
- A. εrF
- B. εr/F
- C. F/εr
- D. Fεr
Explanation
The force between charges in a dielectric medium is reduced by a factor equal to the relative permittivity (or dielectric constant) of that medium. Therefore, the new force F' = F_air / εr.
Last updated
About Electrostatics
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.
Practise Electrostatics
831 free Electrostatics MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Physics questions like this
Physics is on 13 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
1/C_eq = 1/C_1 + 1/C_2 + 1/C_3 + ... + 1/C_n
1 N/C equals to:
1 volt x 1 ampere is equal to:
10 V potential difference is applied across the plate of the 1 µF capacitor. What is the energy stored in the capacitor?
12 J work is to be done against an existing electric field to take a charge of 0.01C from A to B. Find the potential difference between B and A: