Final answer:
An incorrectly wired circuit with a bulb, switch, and battery can cause the bulb to light up when the switch is open and turn off when the switch is closed due to potential errors like a short circuit when the switch is closed.
Step-by-step explanation:
The question pertains to the labeling of devices in a circuit diagram consisting of a bulb, switch, and battery. If a student observes that the bulb is on when the switch is open but off when the switch is closed, this suggests an incorrect circuit configuration, potentially a short circuit when closed. Usually, a switch is meant to complete the circuit when closed, allowing current to flow and light the bulb.
The incorrect behavior described could be due to wiring errors like connecting the bulb in parallel with the switch, causing the bulb to light up only when the switch is open. The correct configuration should have the bulb and switch in series to ensure proper operation of the switch as a control element in the circuit.