There are a multitude of electrical and electronic components, each having their own unique ability. But, there are three components that are used more often than the others. These three components are the Resistor, Capacitor and Inductor.
So, what is the main difference between a resistor, capacitor and inductor?
The main difference between a resistor, capacitor and inductor is what each does with energy. A resistor dissipates energy in the form of heat, a capacitor stores energy in the form of an electric field, and an inductor stores energy in the form of a magnetic field. Also, each of these components have different functions which play an essential role in electrical and electronic circuits. This article shall take a more in-depth look at each of these.
The resistor, capacitor and inductor
Before we take a look at the differences between these three components, let’s take a brief look at each component to see what they are all about.
What is a resistor?
Of the three components, the resistor is the most commonly used. The resistor plays a vital role in electrical and electronic circuits. Its main purpose is to limit the flow of current. It does this by providing a resistance to the flow of current. The greater the resistance, the less current can flow, and the lower the resistance, the more current can flow. Current is a form of electrical energy and when it flows through a resistor, this energy is converted into heat energy (which is dissipated into the surroundings).
Other than just limiting current, a resistor can be used for many other purposes which include, voltage division, heat generation, matching and loading circuits, gain control and setting time constants.
What is a capacitor?
Next up we have the capacitor. A capacitor is composed of two conducting plates that are separated by a dielectric (which is an insulating material). The main purpose of a capacitor is to store energy in the form of electrical energy. This stored energy can be released back into the circuit when required. The amount of electrical energy a capacitor is capable of storing is determined by its capacitance. The higher the capacitance, the more energy it can store, and vice versa. Capacitors allow Alternating Current (AC) to pass, but block Direct Current (DC).
Other than energy storage, capacitors are used for power conditioning, noise filtering, remote sensing, and signal coupling/decoupling.
What is an inductor?
Last, but not least, is the Inductor. Inductors, also sometimes referred to as a coil or choke, are an electronic component that stores energy in a magnetic field when current flows through it. They are constructed using an insulated copper wire that is wound into a coil around a core (which is usually magnetic iron or ferrite). Inductors also have the ability to oppose changes in current which is determined by their Inductance. The higher the inductance the more effective an inductor is at opposing changes in current. Because of this fact, inductors block AC, but allow DC to pass. A wire with more coils (turns) is going to have a higher inductance.
The applications of inductors include; choking, blocking, attenuating, filtering/smoothing high frequency noise, storing and transferring of energy.
What is the difference between a resistor, capacitor and inductor?
The main difference between a resistor, capacitor and inductor, is what happens with current flowing through them. Energy is the common theme they share, however, what happens with energy in each of them varies. When current flows through a resistor, energy is dissipated in the form of heat. In a capacitor energy is stored in the form of an electric field when current flows through it. And when current flows through an inductor, energy is stored in a magnetic field.
Other than that, the other major differences between these components include;
- Main functionality
- Construction
Main functionality
Other than what each does with energy, the other difference between a resistor, capacitor and inductor, is the main functionality and the applications they are used in. The main function of a resistor is to limit current, whereas the main function of a capacitor is to store charge for later use and the inductor’s primary purpose is to oppose any change in current. As there is a difference in their functionality, so too are the applications they will be used for.
Construction
How a resistor, capacitor and inductor is constructed is another difference. As we just saw, each has a different function. They get these unique functions due to the way that they are constructed (as well as the materials that they are constructed with).
Difference between a capacitor and inductor
Of the three components, the capacitor and inductor are quite similar in that they both store energy. But, the way they store energy is their major differentiation. A capacitor stores energy in an electric field, while an inductor stores energy in a magnetic field. But, there is another difference between these two components.
There are two types of current that can flow through an electrical/electronic circuit. The current can either be an Alternating Current (AC) or a Direct Current (DC). When it comes to a capacitor, it blocks Direct Current, but allows Alternating Current to pass. Inductors on the other hand allow Direct Current to pass, but block Alternating current.
Summary of the differences between a resistor, capacitor and inductor
Below is a table summarising the differences between a resistor, capacitor and inductor.
| Resistor | Capacitor | Inductor | |
| Main function | Limit the flow of current | Store energy which it can supply to a circuit later | Oppose any changes in current |
| What it does with energy | Dissipates it | Stores it in an electric field | Stores it an magnetic field |
| Applications | voltage division, heat generation, matching and loading circuits, gain control and setting time constants | power conditioning, noise filtering, remote sensing, and signal coupling/decoupling | choking, blocking, attenuating, filtering/smoothing high frequency noise, storing and transferring of energy |
| Construction | Conductive film wrapped in a helix shape and covered by insulating material | Two conductive plates separated by a dielectric (insulating material) | A copper wire wrapped in a coil around a core (either magnetic iron or ferrite) |
