Updated: Jun 4, 2023

What is electric current?

Electric current flow

In an electrical circuit, current flows from the positive terminal of a power source, such as a battery, through the circuit and back to the negative terminal. The flow of current is determined by a number of factors, including the voltage of the power source, the resistance of the circuit components, and the amount of current flowing through the circuit.

It is important to note that the flow of current is accompanied by the transfer of energy, which can cause heating of the circuit components and, in some cases, cause damage to the components or even start a fire. Therefore, it is important to use appropriate safety measures, such as circuit breakers and fuses, to prevent excessive current from flowing through a circuit.

The flow of current in a circuit is an important factor in the operation of electrical devices and systems. The amount of current that flows in a circuit can affect the performance of electrical devices, as well as the amount of heat generated by the circuit. It is also important to consider the safety implications of electrical current, as high levels of current can be dangerous and potentially cause electrical shock or fires.

Types of electric current

Current can be either direct current (DC) or alternating current (AC). Direct current is a type of current that flows in a single, constant direction, whereas alternating current changes direction periodically.

So basically, there are two main types of electric current: direct current (DC) and alternating current (AC).

Direct Current (DC)

Direct current is a type of electric current that flows in a single, constant direction. It is often produced by batteries and is used to power electronic devices such as cell phones, laptops, and digital cameras.

Direct Current (DC) is a type of electric current that flows in a single, constant direction. It is produced by sources such as batteries, fuel cells, and photovoltaic cells, and is used to power many electronic devices, including cell phones, laptops, and digital cameras.

In a DC circuit, the flow of electrons is steady and unidirectional, from the negative terminal of a power source (such as a battery) to the positive terminal. The magnitude of the current is determined by the voltage of the power source and the resistance of the circuit.

This relationship is described by Ohm's Law, which states that the current (I) in a circuit is equal to the voltage (V) divided by the resistance (R)

I = V/R.

DC circuits can be simple or complex, and can include components such as resistors, capacitors, and diodes, which are used to control the flow of current and regulate the voltage. In some applications, DC power may be converted into AC power using an inverter, which allows the use of AC-powered devices in a DC-powered environment.

DC current is often preferred over AC current for certain applications because it is more efficient and predictable. For example, DC power can be stored in batteries, which makes it ideal for portable electronic devices. Additionally, the constant direction of flow in a DC circuit makes it easier to control the current and to regulate the voltage in the circuit.

Alternating Current (AC)

Alternating current is a type of electric current that changes direction periodically. It is often generated by power plants and transmitted over long distances to homes and businesses. AC is more efficient than DC for transmitting electrical power over long distances because it can be transformed into high voltages, which reduces power losses during transmission.

Alternating Current (AC) is a type of electric current that changes direction periodically. Unlike direct current (DC), which flows in a single, constant direction, AC changes direction many times per second. This property of AC makes it well suited for transmitting electrical power over long distances, as it can be transformed into high voltages, which reduces power losses during transmission.

In an AC circuit, the voltage and the current change periodically, with the voltage reaching a maximum in one direction, then decreasing to zero and reversing direction, before reaching a maximum in the opposite direction. The frequency of this change is measured in Hertz (Hz), with most AC power systems operating at a frequency of 50 Hz or 60 Hz.

AC power is generated by power plants using turbines that are driven by steam, water, wind, or other sources of mechanical energy. The AC voltage generated by the power plant is transmitted over long distances using high-voltage power lines, and is then transformed into lower voltages for use in homes and businesses.

In an AC circuit, the current and voltage are not always in phase with each other. This is because the impedance of the circuit, which is composed of resistance, inductance, and capacitance, affects the flow of current. This relationship between the current and voltage in an AC circuit is described by complex impedance, which is a combination of resistance and reactance.

AC current is preferred over DC current for many applications because it is more efficient for transmitting electrical power over long distances. Additionally, AC devices, such as motors and generators, are often less expensive and more efficient than their DC counterparts. AC power is also more versatile than DC power, as it can be easily transformed into different voltages using a transformer.