Question

When it is necessary to switch on an electrical current from a remote location, which devices could be used?

Answer 1

A classic example is a remote control. The mechanical force exerted by pressing the switches produces electric current (often times creating the electrical continuity of contacts when switch is pressed) within the remote control device allowing it to send radio signals to the receiver.

Answer 2

Answer: Remote control.

Explanation: The most classical example of a device that is used with this objective is the remote control (or clicker).

While the first remote controls used ultrasonic pulses, nowadays they use infrared radiation (there are other types, but this is the most common one), this is what allows them to work from distance. There are "codes" in the radiation that are read by a "camera" and are interpreted for things like turn on the power (and other things, maybe control a drone, change the channel, etc).