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Two capacitors are connected in a circuit with two batteries and a switch S. The system is in steady state with S open. When S is closed, which of the following statements correctly describes the energy exchange?

1. Both batteries supply energy and heat is dissipated in the process.
2. Both batteries supply energy to increase the stored energy of each capacitor independently.
3. One battery supplies energy while the other absorbs energy, with no heat loss.
4. One battery supplies energy, the other absorbs energy, and heat is dissipated in the process.

Correct answer: One battery supplies energy, the other absorbs energy, and heat is dissipated in the process.

Solution

When S is closed, charge redistributes. Because the two batteries have different EMFs driving current through the loop, one acts as a source (supplies energy) and the other acts as a load (absorbs energy). The redistribution of charge always involves heat dissipation due to the inherent resistance (or even ideally, electromagnetic radiation). Option D is correct.

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