Which principle states that the total electric charge in an isolated system remains unchanged?

• A. Conservation of Mass
• B. Conservation of Energy
• C. Conservation of Charge
• D. Conservation of Momentum

Answer: (C)

The principle being tested is the conservation of electric charge: in an isolated system, the total amount of charge stays the same even as charges move or are redistributed.

Charge can flow from one object to another, but you can’t create or destroy net charge. A simple example is when charges are rearranged in a circuit or within materials—electrons may move, but the total charge of the entire system remains constant. In many everyday situations, you can see this balance: if one part of a system becomes negatively charged, another part must carry an equal amount of positive charge so that the total doesn’t change.

The other principles describe different quantities. Conservation of mass concerns the amount of matter, conservation of energy concerns the ability to do work or produce heat, and conservation of momentum concerns motion and forces. None of these specifically enforce a fixed total electric charge, which is what this question is asking about.

So the correct principle is conservation of charge.