Q. An empty capacitor is connected to a 12.0-V battery and charged up. The capacitor is then disconnected from the battery, and a slab of dielectric material (κ = 2.8) is inserted between the plates. Find the magnitude of the amount by which the potential difference across the plates changes.
Q. A meter stick lies on the bottom of a 100-cm-long tank with its zero mark against the left edge. You look into the tank at a 30 angle, with your line of sight just grazing the upper left edge of the tank. What mark do you see on the meter stick the tank is (a) empty, (b) half full of water, and (c) completely full of water.