Download Conceptual Questions Chap. 13

Conceptual Questions Chap. 16
1.
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.
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.
2.
Distinguish between electric potential and electrical potential energy.
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.
3.
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?
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.
4.
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?
In the first case, the stored energy increases. In the second case, the stored energy
decreases.