Difference Between AC and DC Currents (With Table)

Electric current can be divided into two types: alternating current (AC) and direct current (DC) (DC). In alternating current, the current alternates between two directions regularly – forward and backwards. In the case of direct current, the current flows in a single order and at a constant rate. The primary distinction between alternating current and direct current is how the electrons move.

AC vs DC Currents

The main difference between alternating current and direct current is that direct current is constant and unidirectional, so electrons always flow forward. On the other hand, when alternating current travels in numerous directions, the movement of electrons is first in the forward order and then in the reverse order, as shown in the diagram below:

The flow of electric charges occasionally changes direction in alternating current. AC is the most often used and desired electric power source for a wide range of equipment in the home, workplace, and other structures of all types. An electric generator based on the concepts of Michael Faraday was used to test it in 1832.

Direct current, unlike the alternating current, does not flow at a predetermined rate at all. A constant voltage and a single-direction flow characterise the electric current. DC is mostly used for powering electronic gadgets and for recharging battery packs. For example, batteries for mobile phone cameras and torches, flat-screen televisions, and electric cars. Plus and minus signs, a dotted line, and a straight line all appear in DC.

Comparison Table Between AC and DC

Parameters of ComparisonAC CurrentDC Current
DefinitionAn Alternating Current (AC) is a current that, while passing through an electric circuit, changes the direction of the flow of electrons.The flow of electrons within the electrical circuit is unidirectional in the Direct Current circuit.
VariantsWaveforms such as square, triangular, circular, and sinusoidal are examples.In nature, something is pulsating with life and is pure in form.
Source of GenerationAll of the Alternating Current Generators and the power grid are the primary sources of AC currents.Direct Current generation is made possible by using all of the cells or batteries in the system.
Electron Movement and DirectionThe electrons are constantly changing the direction of the flow, which includes both forward and backward motion.The electron movement is unidirectional, i.e., the electrons only move in one direction, which is forward.
Current MagnitudeOver time, the magnitude of alternating current changes.Direct current has a constant amplitude that does not change with time.
Power FactorThe power factor of alternating current varies between 0 and 1.Direct current has a power factor of one that is always present.

What is AC Current?

An Alternating Current is described as the flow of electrons in an electric circuit that alternates periodically inside the course. It serves as a source of energy for the industries listed below:

  1. People’s homes as well as those of their neighbours.
  2. Offices and places of employment.
  3. Buildings or apartments in the vicinity.
  4. Electric motors mostly rely on this kind of energy.
  5. Transformers can benefit from their use as voltage control devices.

When using an Alternator, a device that creates Alternating Currents, it is possible to manufacture AC with relative ease and speed. To generate it, we must first have a magnetic field source.

A wire loop will be spun inside the source, and electrons will begin to flow in only one way.

The rotation of the wires can be induced by any turbine or electric motor as the source, of course. Because of the various magnet ports present within the wire, the direction of electrons is constantly changing, resulting in the generation of 9V alternating current.

What is DC Current?

A Direct Current is described as the flow of electrons within an electric circuit that is unidirectional; that is, it flows only in one direction, in the forward direction.

Also determined by the passage of electrons from the negative pole to the positive pole of the magnet is the direction of the magnet’s magnetic field.

The most significant disadvantage of DC is that it is impossible to travel long distances because it begins to lose its energy as soon as it starts. Aside from that, the frequency of DC is always zero (0).

The flow of electrons always occurs from a region with a high electron density to a zone with a lower electron density than the area with a high electron density.

The direction and voltage of DC are relatively expensive and difficult to achieve when changing the law and voltage of DC. As a result, it is an unsuitable medium for long-distance voltage transmissions.

Nowadays, most computer accessories and gadgets operate on direct current (DC), such as any solid-state equipment, which can require up to 14 V of DC.

The most common real-world example of Direct Current is the battery, which is now found almost everywhere. All batteries are equipped with two terminals labelled as positive and negative.

The current will pass between the two terminals of the battery, resulting in the generation of direct current.

Some of the most typical DC applications are as follows:

  1. Using Automotive Appliances to Recharge Batteries
  2. Application and pricing for aircrafts
  3. Other gadgets that operate at low voltage and current.
  4. Marine DC High Voltage lines are a convenient alternative because, in a subsea environment, alternating current is not the most reliable option available.

In such circumstances, the electricity is first generated in alternating current (AC) form and then transmitted to direct current (DC) form via various electric wires.

Later, the current is changed back to alternating current at the destination for routine use. As a result, while converting from alternating current to direct current is very inexpensive and straightforward, doing so in reverse is more expensive.

Main Differences Between AC and DC

  1. The direction of flow in alternating current reverses, whereas flow in direct current never changes.
  2. DC is defined as current with a constant magnitude, whereas AC is defined as current with a volume that fluctuates with time (or frequency).
  3. Impedance and resistance are the passive parameters for alternating current, whereas resistance is for direct current and vice versa.
  4. A constant power factor of one is present in DC. However, the value of a constant power factor fluctuates between 0 and 1 in DC.
  5. DC can’t have a frequency greater than 0. The frequency of the alternating current, on the other hand, fluctuates between 50 and 60 hertz (Hz).
  6. In contrast to alternating current, direct current is always unidirectional, meaning that electrons can only go from the high-density electron side to the low-density electron side.


It makes no difference which of the two currents is preferable because each has its own set of advantages and disadvantages.

After learning that AC can be converted to DC with the use of an Adapter or similar instrument, we can see that DC cannot be converted to AC as readily and that this is why DC is a poor choice for long-distance power transfer. Overall, though, both alternating and direct currents are excellent tools for transferring electricity from one area to another.


  1. https://iopscience.iop.org/article/10.1088/1361-6668/aac294/meta
  2. https://scienceweb.uz/publication/990