Conceptual Questions Chap. 16

1. Conceptual Questions Chap. 16 You should stay inside the car. If you step outside, a 20 kV potential difference could exist between you and the ground, causing a large charge to flow through you and likely resulting in injury. • Suppose you are sitting in a car and a 20–kV power line drops across the car. Should you stay in the car or get out? The power line potential is 20 kV compared to the potential of the ground. • Distinguish between electric potential and electrical potential energy. • Why is it dangerous to touch the terminals of a high-voltage capacitor even after the voltage source that charged the capacitor is disconnected from it? What can be done to make the capacitor safe to handle after the voltage source has been removed? • What happens to the energy stored in a capacitor if a dielectric is inserted into the capacitor while it is connected to a battery? What if the battery has been disconnected? Electric potential is a measure of the electrical potential energy per unit charge. Electrical potential energy is a measure of the potential energy of a system consisting of a charge in an electric field. The plates of a capacitor often remained charged long after the voltage source is removed. Touching the terminals grounds the capacitor (under normal circumstances) and large amounts of charge can pass through you. Instead, the capacitor can be “short-circuited” with a conductor having an insulating handle. In the first case, the stored energy increases. In the second case, the stored energy decreases.