Final answer:
A countdown timer is the most suitable device to switch off a lamp 10 seconds after the switch is turned off, as it is specifically designed to count down from a preset time to perform an action, the correct option is 2).
Step-by-step explanation:
The question you have asked is related to timed control systems, which involve accurately timing the operation of electrical components such as a lamp. The most directly applicable timer to use for switching off a lamp 10 seconds after a switch has been turned from the on to off position would be a countdown timer.
Unlike a stopwatch or an alarm clock, a countdown timer is designed to count down from a set time to zero and then perform an action, in this case, turning off the lamp. Digital timers can also be set to countdown, but in this context, countdown timer specifically refers to a device intended for such purposes.
Analog and digital clocks as well as stopwatches, while they can measure elapsed time, are not as suitable for this application, especially since a countdown timer offers a more straightforward and automatic solution for the scenario described. Measuring elapsed time is essential in various contexts, and in this instance, a countdown timer serves as the most practical tool to ensure that exactly 10 seconds pass before the lamp is switched off.