resistance

In an electric circuit, it is a component that limits the flow of current with respect to voltage, and the difficulty of flow is determined by resistivity. It is one of the basic and important components used to construct switching circuits. It is mainly used to control (step down) voltage, but power loss due to heat generation occurs. All substances have a resistive element—materials with very low resistance are used as conductors, while materials with very high resistance are used as insulators. A pure resistor allows an alternating current with a waveform similar and in-phase with the voltage.