Atoms can give and take electrons from each other. If some atoms have too many electrons and others have not enough, electrons will run to where they are missing. This flow of electrons is called an electric current.
An electric generator can separate electrons and protons. It can be powered by energy from sunlight or burning fuel, from the flow of water or wind, and even from your personal energy when you apply force. For example, in our case, when you twist a handle.
The "plus" sign marks the place where there are more protons, and the "minus" sign marks the place where there are more electrons. If there is a suitable road between the minus and the plus, an electric circuit is created, along which electric current flows. By turning the wire chips, you change the direction of the road on which the electric current can run. The wires don't care which way the electrons run. Turn the wires as you wish to build an electrical circuit.
There are parts in our circuit for which the direction of current is crucial. These are LEDs. LED has two poles - its own "plus" and "minus". In order for the LED to work, its polarity must coincide with the plus and minus of the current of electricity in the circuit, so the current can pass through the LED only in one direction. Try spinning the LED chip — and you will see that its bulb lights up only when the pluses and minuses are in their places.
Electricity can be converted not only into light, but also into sound — with the help of a speaker. Try putting together an electrical circuit so that the speaker receives an electrical signal from a generator and makes a sound.
Another part of our circuit is a resistor. The resistor prevents electrons from running through the circuit, this is called resistance. Imagine that the resistor makes the wire that the electrons run through very viscous and sticky. Therefore, it is harder for the electrons to run and the current becomes smaller.