A long copper wire is connected across the terminals of an ideal battery
PHYSICS · Single correct · A Level · Physics · Electricity · Electricity
Problem
A long copper wire is connected across the terminals of an ideal battery. After several minutes the battery is suddenly removed while the wire remains intact. Which statement best describes what happens immediately after the battery is disconnected?
(a) The current increases briefly because removing the battery eliminates the battery's internal resistance, leaving only the low resistance of the wire.
(b) The current continues unchanged because the electrons already in motion experience negligible resistance, so nothing immediately slows them.
(c) The current drops essentially to zero because the driving electric potential difference is gone.
(d) The current reverses direction to oppose the sudden change in magnetic field created by disconnecting the battery.