How does a slider rheostat work?

In the rheostat, a nickel wire 2 is wound on the ceramic cylinder 1. The wires are insulated from each other. The ends of the wire are brought out to the terminals K1 K2 Along the rod 3, connected to the terminal K3, the slider moves 4. It is pressed by the contacts 5 to the turns of the winding. The electric current in the circuit passes from the terminal K1 to the turns of the wire, from the turns to the polchunk, and through it to the rod 3 and K. clamp Kz. Moving the rheostat slider? you can adjust the current in the circuit.