Capacitor Concepts and Electric Fields

How does the capacitance of a parallel-plate capacitor change if the area of the plates is increased and the distance between them is decreased?

• Increases

• Decreases

• Remains the same

• Cannot be determined

What happens to the capacitance of a capacitor when a dielectric material is inserted between its plates?

• It decreases.

• It increases.

• It remains unchanged.

• It becomes zero.

If a charged capacitor is disconnected from its battery and then a dielectric material is inserted between its plates, what happens to the voltage across the capacitor?

• It increases.

• It decreases.

• It remains the same.

• It becomes zero.

When a dielectric material is inserted into a charged capacitor that is disconnected from its battery, what happens to the total charge stored on the capacitor?

• It increases.

• It decreases.

• It remains the same.

• It becomes zero.

In a parallel plate capacitor, in which direction does the electric field point?

• From the negative plate to the positive plate.

• From the positive plate to the negative plate.

• Perpendicular to the plates, but direction depends on charge magnitude.

• Parallel to the plates.

What factors determine the capacitance of a parallel plate capacitor?

• The voltage across the plates and the electric field strength.

• The area of the plates and the distance between them.

• The charge on the plates and the permittivity of free space.

• The surface charge density and the electric field.

What is necessary for electric current to flow in a circuit?

• A high resistance.

• A difference in electric potential.

• An insulator.

• A perfectly level surface.

When a discharged capacitor is connected to a battery, how do electrons move to charge the capacitor?

• Electrons flow from the positive plate of the capacitor, through the battery, to the negative plate of the capacitor.

• Electrons flow from the negative terminal of the battery to one capacitor plate, and from the other capacitor plate to the positive terminal of the battery.

• Electrons jump directly across the insulator between the capacitor plates.

• Protons move from the positive terminal of the battery to one capacitor plate, and electrons move from the other capacitor plate to the negative terminal of the battery.

If a capacitor stores 200 units of charge at 12 volts, how much charge will it store if the voltage is increased to 36 volts?

• 200 units

• 400 units

• 600 units

• 800 units

When a charged capacitor is connected to a light bulb, how do electrons flow to light up the bulb?

• From the positively charged plate to the negatively charged plate.

• From the negatively charged plate to the positively charged plate.

• Electrons do not flow; protons move to balance the charge.

• The light bulb generates its own electrons to light up.