What Is A Resistor?
A resistor is a passive two-terminal electrical component with the primary function of limiting the flow of current in a circuit, a function that is key to the operation of most circuits. They are typically constructed of metal wire or carbon and engineered to maintain a stable resistance value over a wide range of environmental conditions. Unlike lamps, they do not produce light, but they do produce heat as electric power is dissipated by them in a working circuit.
A resistor works on the principle of Ohm’s law and the law states that the voltage across the terminals of a resistor is directly proportional to the current flowing through it. The effect of a resistor is referred to as resistance. The resistance of a circuit is generally measured in ohms. This relationship is represented by the equation: R=V/I.
In electronic circuits, resistors are used for many purposes which include: delimit current flow, adjust signal levels, heat generation, control gain, matching and loading circuits, and voltage division, to bias active elements and terminate transmission lines, among other uses.
What You Need To Know About Resistor
- A resistor is an electronic component used to resist the flow of current in a circuit in order to maintain proper voltage or current through it.
- Resistors are used to reduce current flow, divide voltages, terminate transmission lines and adjust the signal levels.
- Resistors create power loss and generate heat.
- Resistors are majorly used in precision circuits, radio frequency and logic circuits etc.
- The Unit of resistance of a resistor is ohms.
- In a DC circuit when a resistor is added in series with an inductor, the value of current is small and afterward it increases with time.
- A resistor works by converting excess electrical energy into heat, which is dissipated into air.
- The resistance of the resistor is given by Voltage/Current (R=V/I).
What Is A Capacitor?
A capacitor is an electrical circuit which behaves as a charge storage device. It holds the electric charge when we supply a voltage across it, and it gives up the stored charge to the circuit as when required. They’re like a fully charged electric battery. Capacitors are one of the three fundamental electronic components that form the foundation of a circuit along with resistors and inductors.
The most basic construction of a capacitor consists of two parallel conductors (usually metallic plates) separated by a dielectric material. When voltage source is connected across the capacitor, the conductor (capacitor plate) attached to the positive terminal of the source becomes positively charged and the conductor (capacitor plate) connected to the negative terminal of the source becomes negatively charged. Now, due to presence of dielectric in between the conductors, ideally no charge can move from one plate to the other. Therefore, there will be a difference in charging level between these two conductors (plates). In effect, an electric potential difference appears across the plates.
The effect of a capacitor is referred to as capacitance, which can be defined as the quantity of charge accumulated in the capacitor for passing a voltage across the capacitor. In other words, a capacitor adds capacitance to a circuit. Therefore, there is a direct relationship between the charge and voltage of a capacitor. Which can be represented by the equation: charge/Voltage (C=Q/V). The Capacitance of a capacitor is measured in farads.
What You Need To Know About Capacitor
- Capacitor is an electronic component used to store charges or energy in the electric field generated by the externally applied potential.
- Capacitors are used for filtering, smoothening, coupling different sections of the circuit and limiting high voltage transient across the circuit.
- There is no loss/leakage of energy or charges in capacitors.
- Capacitors are used in waveform generation, filtering, blocking and bypass applications.
- The unit of capacitance of a capacitor is farads.
- In DC when capacitor is added in series with a resistor, the current initially becomes high but later falls to zero.
- Capacitor works by keeping the positive and negative charges separated from each other.
- The capacitance of the capacitor is given by charge/Voltage (C=Q/V).
Also Read: Difference Between Active And Passive Components
Difference Between Resistor And Capacitor In Tabular Form
BASIS OF COMPARISON | RESISTOR | CAPACITOR |
Description | A resistor is an electronic component used to resist the flow of current in a circuit in order to maintain proper voltage or current through it. | Capacitor is an electronic component used to store charges or energy in the electric field generated by the externally applied potential. |
Use | Resistors are used to reduce current flow, divide voltages, terminate transmission lines and adjust the signal levels. | Capacitors are used for filtering, smoothening, coupling different sections of the circuit and limiting high voltage transient across the circuit. |
Power Loses | Resistors create power loss and generate heat. | There is no loss/leakage of energy or charges in capacitors. |
Application | Resistors are majorly used in precision circuits, radio frequency and logic circuits etc. | Capacitors are used in waveform generation, filtering, blocking and bypass applications. |
Unit Of Measurement | The Unit of resistance of a resistor is ohms. | The unit of capacitance of a capacitor is farads. |
Behavior In DC Circuit | In a DC circuit when a resistor is added in series with an inductor, the value of current is small and afterward it increases with time. | In DC when capacitor is added in series with a resistor, the current initially becomes high but later falls to zero. |
Functionality | A resistor works by converting excess electrical energy into heat, which is dissipated into air. | Works by keeping the positive and negative charges separated from each other. |
Equation | The resistance of the resistor is given by Voltage/Current (R=V/I). | The capacitance of the capacitor is given by charge/Voltage (C=Q/V). |