Question

What is the purpose of a resistor ?

Answer 1

A resistor is a two-terminal passive electrical component that acts as a circuit element by implementing electrical resistance.The movement of charge is what we usually refer to as electricity. Charges are borne by free-flowing electrons at a lower atomic stage. The electrons in conductors are closely bound to the atoms, so they can be liberated and flow in a generally uniform direction with a little prompting.

Complete answer:
Conductivity is the property that allows electrons to flow freely, while resistivity is the property that prevents them from doing so. An electric field propels the charges forward. To make them flow, we'll need an electric potential source that moves electrons from a low potential energy state to a higher potential energy state. Based on the amount of charges passing through it, different materials respond to electricity in different ways. When we strike a surface with enough energy, it emits light, just like a semiconductor in a Light Emitting Diode (LED).

Now, how do we regulate electron energy? To increase it, add a source; to decrease it, delete the source . The current issue is that the source's capacity cannot always be quickly changed. When we use certain sources to produce a certain amount of potential, they are effective. So, what other way do we have to monitor the amount of energy hitting the LED in order to make it useful?

The answer is in the regulation of electron flow in the circuit itself, not in the source. We can accomplish what we want if we add any extra material that opposes the passage of electrons (RESISTOR). Resistors are used in electrical circuits for a variety of purposes, including reducing current flow, adjusting signal speeds, dividing voltages, biassing active components, and terminating transmission lines.

Note: There is a difference between resistance and resistor. When a potential differential is applied across a conductor, the resistance determines how much current flows through it. A resistor is an electrical component with a fixed resistance, such as $1\,ohm$, $10\,ohms$, $100\,ohms$, or $10000\,ohms$.