What is resistor and its uses?
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.
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.
- Position the resistor with the gold or silver color band to the right..
- Read the color sequence that must be decoded to determine resistance.
- Determine the coded number for the resistive value.
- Determine the tolerance of the resistor.
- Determine the decoded number for the resistive value.
- 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.
- A capacitor (originally known as a condenser) is a passive two-terminal electrical component used to store energy electrostatically in an electric field. Unlike a resistor, a capacitor does not dissipate energy. Instead, a capacitor stores energy in the form of an electrostatic field between its plates.
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.
- Electrical resistance is measured by either of two methods: constant current or constant voltage. The constant current technique sources a known current through an unknown resistance and the resulting voltage is measured. This technique is generally used for resistance values below 200M ohms.
- Power conditioning. Reservoir capacitors are used in power supplies where they smooth the output of a full or half wave rectifier. They can also be used in charge pump circuits as the energy storage element in the generation of higher voltages than the input voltage.
- A transistor is a miniature electronic component that can do two different jobs. It can work either as an amplifier or a switch: Transistors can also work as switches. A tiny electric current flowing through one part of a transistor can make a much bigger current flow through another part of it.
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.
- The voltage dropped by a resistor is given by Ohm's Law: V = I R. So if you know exactly how much current your device will draw, you could choose a resistor to drop exactly 7.5 V, and leave 4.5 V for your device, when that current is run through it.
- In a series circuit, adding more resistors increases total resistance and thus lowers current. But the opposite is true in a parallel circuit because adding more resistors in parallel creates more choices and lowers total resistance. If the same battery is connected to the resistors, current will increase.
- Voltage is the potential difference between the source & any point in the circuit. Voltage drop means, amount of voltage by which voltage across load resistor is less then the source voltage. Voltage across the resistor = Potential difference between the two terminal of the resistor, which here is V(load).
Updated: 3rd October 2019