After the control switch has been closed for 7 minutes and is now opened, what will the state of the red light be five seconds after opening?

The correct answer is that the red light will be OFF five seconds after opening the control switch. This occurs because when the control switch is closed, it allows current to flow to the red light, keeping it in an ON state. Once the switch is opened, the circuit is interrupted, and no current can flow to the light.

Typically, lights do not hold a charge or have a sustained current that would keep them illuminated after power is removed. Therefore, studying the behavior of standard lighting circuits reveals that once the switch is opened, the light will turn off almost immediately, reaching an OFF state within just a few seconds.

In this case, having been previously closed for 7 minutes does not matter for its state after the switch is opened since the circuit interruption stops the current flow immediately. Hence, we can conclude that the red light will definitely be OFF five seconds after the control switch is opened.