A model for electric current

An electric current is a flow of tiny charged particles called electrons. The animation represents the current as a flow of water in a pipe.

In an electric circuit, the cell (battery) supplies the energy to push the electrons around the circuit. In the light bulb, this energy is converted to light and heat.

In the simulation, the water is pushed through the pipe by a pump. The paddle wheel represents the light bulb and converts the energy from the pump into kinetic (movement) energy of the rotating paddle wheel.

If you use 2 pumps, the water moves faster and the the paddle wheel turns faster. For an electric circuit, this would correspond to using 2 cells. What would happen to the brightness of the light bulb?

The brightness would increase because the current is increased.

If you use 1 pump and 2 paddle wheels, the wheels turn more slowly because it is harder for the pump to push the water through the pipe. For an electric circuit this would correspond to using 1 cell and 2 light bulbs. What would happen to the brightness of the bulbs in this case?

The brightness would decrease because the current is reduced.