Moderate

Two bodies are charged by rubbing one against the other. During the process, one becomes positively charged while the other becomes negatively charged. Then:

Correct answer: D. Mass of each body changes slightly but the total mass remains the same

  • A. Mass of each body remains unchanged
  • B. Mass of each body changes marginally
  • C. Mass of each body changes slightly and hence the total mass
  • D. Mass of each body changes slightly but the total mass remains the same

Explanation

When two bodies are charged by rubbing, electrons are transferred from one body to the other. This leads to one body becoming negatively charged (gaining electrons) and the other positively charged (losing electrons). In this process, the mass of the negatively charged body slightly increases, while the mass of the positively charged body slightly decreases. However, according to the law of conservation of mass, the total mass of the system remains the same because the electrons are merely transferred from one body to the other, not created or destroyed.Option A is incorrect because it overlooks the mass change due to electron transfer. Option B notes a mass change but fails to recognize that the total mass remains constant. Option C incorrectly suggests that the total mass changes, which violates the conservation of mass. Option D correctly identifies that individual masses change while the total mass remains constant.

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