Faraday's Law of Induction
You can drag the red wire loop with your mouse. This loop is coupled to the galvanometer in the background with electrical leads. However, these cables only obstruct the view, and we therefore have only drawn the yellow and green endpoints of the two cables. Transparent cables! Another triumph of the virtual world!
Move the loop into or our of the magnet, and the galvanometer will indicate a current. How much will depend on the velocity with which you move the loop.