How do resistors actually resist electricity?
- The electrons in the resistor material will have limited mobility compared to a good conductor and better mobility than those of an insulator.
- Mobility or lack of mobility determines the degree of resistance to current.
- Resistivity is a measurable characteristic of different materials.
- some materials have extremely low resistivity, and we call these materials conductors, such as silver, copper, aluminum, etc.
- other materials have a very high resistivity, these insulators are called other materials, such as plastic, glass and air.
However, a third class has a modest resistivity – neither too high nor too low – and we use these materials, such as carbon and some metal oxides, to make components with predictable strength under quite diverse environmental conditions.
The free movement of electrons in a material requires a material that has free electrons, that is, they are able to move with the applied voltage. it turns out that various materials have electrons more or less related to the external structure of the material.
It turns out, moreover, that metals are relatively free and that the other materials (ionic solids) we call insulators are more closely related.
Some materials, such as carbon, are not as good for moving electrons as metals, but they are nevertheless better than very good insulators. we use these materials to make resistors.
All materials, except superconductors, have some resistance. a superconductor is a conductor whose structure is sufficiently fixed to allow an electric current without any resistance.
As a rule, it only works at a very low temperature. Conductance, just to keep our terms, is the reciprocal of resistance.
Drivers who are good at driving electricity (copper, silver, gold). the electrons on the outer valence layer are able to move easily; after all electricity is the movement of electrons.
Insulators that do not conduct electricity (glass, ceramic, plastic). the atomic structure of the material does not allow the movement of electrons. of semiconductors that need to be doped to conduct electricity (silicon, germanium).
In its natural form, a semiconductor does not allow the flow of electrons. after doping, a semiconductor can conduct electricity under certain conditions (study of diodes, LEDs and transistors).
Semiconductors are what allows all modern electronic wonders to exist and our modern way of life to exist. semiconductor devices: computer chip (integrated circuit), transistors, cmos, mosfet, diode, triode, led, etc.
Drivers who are not the best drivers of electricity are called resistors. its molecular structure does not allow electricity to circulate freely, it is more difficult for electricity to circulate; it does not allow the movement of electrons on the outer valence shell easily.
This property is very useful in electronic technology. Resistors are composed of: carbon, carbon stack discs, carbon film, printed carbon resistance, thin film and thin smd resistance, metal film, metal oxide film, wire, foil, cermet, phenolic and tantulum.
The resistors can be used to create voltage dividers. Transistor circuits need resistors to function. resistance is used to describe a load. a television connected to the wall is a giant resistance with regard to the electric network (study of the thevenins theorem).
Even the best drivers have resistance, there is no way out.
Superconducting technology has no resistance (zero ohms) but requires the temperature to be below -200 ° F, a very exotic technology.