A fun science demonstration is to take an old-timey hand crank electrical generator, crank it by hand with nothing attached to the power output, then attach a l

A fun science demonstration is to take an old-timey hand crank electrical generator, crank it by hand with nothing attached to the power output, then attach a light bulb and crank it a second time. The amount of resistance resulting from the light bulb using the generated electricity is remarkable. It is much harder to turn the crank with the light bulb attached and that really drives home that electrical devices really do use a lot of energy.