Dear researchers;
In electrical heating elements, there is a wire (that is converted to spring) in a steel tube that is filled with fireclay. When the tube is rolled (to compress the fireclay and reduce the pipe radius), the electrical resistance of the wire decreases. Such reduction is more drastic for high-radius wires (the electrical resistance of thicker wires decreases more than the one for thin wires). Can anyone answer me why it happens?
Thank you all