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Electricity is a part of the lives of all modern human beings. We use it every day for several different applications. Electric current is the rate of flow of electrons in a conductor. We know that electrons are negatively charged particles in the sub-atomic configuration of the atom. These electrons are in motion at all times and are not unidirectional. Once voltage is applied, the electrons start moving in one direction, and the electric current starts flowing through the conductor.
The Direction of Electric Current
The direction of the electric current is opposite to the direction of the movement of electrons. Conventionally, current flows from the positive to the negative terminal of a battery and indicates a positive charge flow. The flow of electrons occurs from the negative to the positive terminal as these are the negatively charged particles that get repelled by the negative terminal.
What is the Unit of Electric Current?
The magnitude of electric current is measured in coulombs per second.
The unit of electric current is Ampere in SI, which is represented as “A.”
One Ampere of electric current means passage of one coulomb of charge across the surface in one second. Further, there are different multipliers like microamp (0.000001A), milliamp (0.001A), etc. An ammeter is a device that is used to measure electric current.
Characteristics of Electric Current
- In general, electric current flows in the direction in which the positive charge moves. Hence, it is directed towards the negative terminal and away from the positive terminal.
- Electric current is measured in Amperes.
- There are two types of electric current, namely, alternating current and direct current. While AC can flow in both directions, DC only flows in one direction.
- When the electrons move from one point to the other, the work that takes place is called electrical energy.
- An electrical measuring device called an ammeter calculates the electric current.
Effects of Electric Current
- Magnetic effects: Electric current can form a magnetic force called the magnetic effect. When you pass an electric current through a conductor, a magnetic field is produced around it. This magnetic field is thereby applied in various electrical applications.
- Heating effects: Upon passing an electric current through a conductor, you will be able to generate heat. This phenomenon is represented as H = I2RT, where T is time, R is the resistance, and I is the amount of current. So, if you pass a small amount of current, the heat generated will be small. Likewise, passing a large amount of current through the conductor raises its temperature.
- Chemical effects: Electric current can break down the components of solutions to their ionic state. You can further observe that the colour of these solutions changes, with metallic deposits on the electrodes. You will also see gas production or bubble formation during this dissolution process.
Prerequisites for Electric Current to Flow
Electric current cannot flow through every type of circuit. To pass an electric current through a circuit, certain specifications need to be followed.
Firstly, there should be a minimum of one source of EMF or voltage that defines the direction of the electrons. Also, the circuit must be closed with a switch for an electric current to pass through the circuit.
Electromotive Force
Electrons move in a particular direction due to the force acting on them. This force is called the electromotive force or EMF. The quantity of EMF is given in voltage, and it can be measured in volts. Without any specific direction, electrons will move randomly in a chaotic fashion. The EMF provides direction and aligns these electrons to a certain extent. The flow of electric current in a conductor is all because of the EMF acting upon the electrons.
Conclusion
Hence, it is easy to understand the basics of electric current. It is simply the rate of movement of electrons in the conductor. The SI unit of electric current in Amperes. Any circuit with an energy source and closed conducting loop can pass the electric current. This can be easily visualised using the water pipe analogy method. The conventional flow of the electric current is opposite to the flow of the electrons. It has heating effects, magnetic effects, and chemical effects.
