a switch and a battery
A circuit consists of a coil, a switch and a battery, all in series. The interval resistance of the battery is negligible compared with that of the coil. The switch is originally open. It is thrown closed, after a time interval Δt. The current in the circuit reaches 80.0% of its final value. The switch then remains closed for a time interval much longer than Δt. The wires connected to the terminals of the battery are then short circuited with another wire and removed from the battery, so that the current is uninterrupted. At the moment 2Δt after the coil is short-circuited, the current in the coil is what percentage of its maximum value?
21
Oct
A circuit consists of a coil, a switch and a battery, all in series. The interval resistance of the battery is negligible compared with that of the coil. The switch is originally open. It is thrown closed, after a time interval Δt. The current in the circuit reaches 80.0% of its final value. The switch [...]