Resistor Action

Small power resistors are typically composed of carbon films encapsulated in plastic shells, while high-power resistors are typically wire wound resistors made by wrapping high resistivity metal wires around ceramic cores.
If the resistance value of a resistor is close to zero ohms (such as a large cross-sectional wire between two points), then the resistor has no blocking effect on the current, and the circuit connected in parallel with this resistor is short-circuited, resulting in an infinite current. If a resistor has infinite or large resistance, the circuit connected in series with the resistor can be considered as an open circuit with zero current. The commonly used resistors in industry are between two extreme situations, which have a certain resistance and can pass a certain amount of current, but the current is not as large as when there is a short circuit. The current limiting effect of a resistor is similar to the effect of a small diameter pipe connected between two large diameter pipes to limit water flow. Resistance, commonly abbreviated as R, is a fundamental property of a conductor that is related to its size, material, and temperature. Ohm's law states that if I=U/R, then R=U/I, the basic unit of resistance is the ohm, represented by the Greek letter "Ω". There is a definition of the resistance value corresponding to one ampere of current generated by applying a voltage of one volt to a conductor. The main function of a resistor is to obstruct the flow of current. In fact, "resistance" refers to a property, and the resistance commonly referred to in electronic products refers to a component such as a resistor. Ohm is often abbreviated as Ohm. The commonly used units for representing resistance values include kiloohms (k Ω), megaohms (M Ω), and milliohms (m Ω)