# What is a resistor?

The word "resistor" comes from the Latin word "resisto" - "resist." A resistor is a technical term used to denote a passive element of an electrical circuit, characterized by a certain value of electrical resistance and serving to linearly convert current into voltage and voltage into current. Let's take a closer look at what a resistor is and why it is used in electrical circuits.

## Resistor characteristics

The resistor is described by a number of characteristics, the main of which is the nominal resistance. In addition, the values of power dissipation, temperature coefficient, permissible limit of deviation from the nominal (specified in the specification) values, maximum operating voltage and excess noise are important.

When working in the microwave (ultra-high frequencies), such parameters of the resistor as parasitic capacitance and inductance become important.

By the nature of the change in resistance, there are constant, variable (rheostat) and trimming resistors.A constant resistor is characterized by a constant value of resistance, the resistance of a rheostat can be changed through various mechanisms, thus affecting the current and voltage of the circuit. A trimmer is a kind of variable resistor, only trimming can be done in very small ranges.

## Scope of resistors

A resistor is one of the most common electronic components; almost no circuit can do without this element. If we talk about the specific effect that the resistor should create in the circuit, it is, above all, a current limitation.