When two plates of a capacitor are connected to a voltage source, what happens between them?

When two plates of a capacitor are connected to a voltage source, what happens between them?

• A. An electric field develops building a charge between the plates
• B. The plates switch polarity
• C. The current path becomes a short circuit
• D. The plates repel away from each other

Answer: (A)

Applying a voltage to a capacitor causes charges to accumulate on the plates, one plate becoming positive and the other negative. This separation of charge creates an electric field in the space between the plates. The field is what stores energy in the capacitor and establishes the voltage across the plates. A brief current flows as the capacitor charges, then stops in an ideal case once the plate voltage matches the source. The plates are held in place by the field, and opposite charges actually attract, not repel. So the key result of connecting to a voltage source is the formation of an electric field between the plates due to charge separation.

Applying a voltage to a capacitor causes charges to accumulate on the plates, one plate becoming positive and the other negative. This separation of charge creates an electric field in the space between the plates. The field is what stores energy in the capacitor and establishes the voltage across the plates. A brief current flows as the capacitor charges, then stops in an ideal case once the plate voltage matches the source. The plates are held in place by the field, and opposite charges actually attract, not repel. So the key result of connecting to a voltage source is the formation of an electric field between the plates due to charge separation.