These are your options:
It can be connected to an LED, or even a voltmeter. This would make it more useful and teach a valuable lesson.
Now spin the motor!
See? It’s free electricity! You get electricity for free
“Um, that’s not a lot of electricity.”
It’s OK, it also applies to larger motors! This AC generator is a great choice!
Remove the gas engine part. Plug in your voltmeter. Now, make the motor turn again.
“Uh, that’s really hard!” “I still don’t produce a lot of electricity!”
Yeah? And? And? You can make electricity from magnets. Free.
Generators like these are the source of all our electricity. This is the difference between a tiny generator that can power just a few light bulbs and a small one.
Is just a matter of scale. And cost. The generators in this last picture can power a whole city. It took probably 20 people working full time for a month to make just one, not including the people it took to mine the materials and smelt them and forge them, etc.
“But this guy on internet said …!”
He was a bullshittit. Did he sell a book?