What is the importance of a resistor?
The main function of resistors in a circuit is to control the flow of current to other components. Take an LED (light) for example. If too much current flows through an LED it is destroyed. So a resistor is used to limit the current.
Devices called resistors let us introduce precisely controlled amounts of resistance into electrical circuits. Photo: Four typical resistors sitting side by side in an electronic circuit. A resistor works by converting electrical energy into heat, which is dissipated into the air.
- A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active elements, and terminate transmission lines, among other uses.
- The reason a light bulb glows is that electricity is forced through tungsten, which is a resistor. The energy is released as light and heat. A conductor is the opposite of a resistor. Electricity travels easily and efficiently through a conductor, with almost no other energy released as it passes.
- In a way, a capacitor is a little like a battery. Although they work in completely different ways, capacitors and batteries both store electrical energy. Inside the battery, chemical reactions produce electrons on one terminal and absorb electrons on the other terminal.
A resistor is an electrical component that limits or regulates the flow of electrical current in an electronic circuit. Resistors can also be used to provide a specific voltage for an active device such as a transistor.
- The first major categories into which the different types of resistor can be fitted is into whether they are fixed or variable. These different resistor types are used for different applications: Fixed resistors: Fixed resistors are by far the most widely used type of resistor.
- resistors are made from small rods of ceramic coated with metal such as a nickel alloy or a metal oxide such as tin oxide. The value of resistance is controlled by the thickness of the coating layer; the thicker the layer, the lower the value of resistance.
- Resistance is the opposition that a substance offers to the flow of electric current. When an electric current of one ampere passes through a component across which a potential difference (voltage) of one volt exists, then the resistance of that component is one ohm.
In short: Resistors limit the flow of electrons, reducing current. Voltage comes about by the potential energy difference across the resistor. The mathematical answer is that a resistor is a two-terminal electric device which obeys, or you could say enforces, Ohm's law: V=IR.
- In general, a change in resistance will change both the voltage across and current through the resistor. For example, consider the simple voltage divider circuit - a voltage source and two resistors , , connected in series.
- Non-linear resistance, does not obey Ohm's Law but has a voltage drop across it that is proportional to some power of the current. Resistance is pure and is not affected by frequency with the AC impedance of a resistance being equal to its DC resistance and as a result can not be negative.
- Voltage Drop - Definition. Wires carrying current always have inherent resistance, or impedance, to current flow. Voltage drop is defined as the amount of voltage loss that occurs through all or part of a circuit due to impedance. This condition causes the load to work harder with less voltage pushing the current.
Updated: 3rd October 2019