Difference Between AC Current and DC Current

What is AC Current?

AC abbreviates “alternating current”. It is an electrical method in which there is a frequent shuffling of positive and negative sides, thereby changing the direction in which electricity flows. It is the most common way to deliver electricity from large-sized power plants to residential and commercial areas. When electricity travels in AC, the voltage keeps fluctuating.

A specially designed machine produces an alternating current called an alternator. This machine makes a current that changes its direction in a fixed time interval. The sole purpose behind producing AC is to supply electrical energy to large distances with much less power loss. The direction-change mechanism works when electrons change their movement.

AC can increase or decrease voltage as per requirements. Experts suggest that AC takes less money to be generated. Nearly all power plants generate electricity in the form of AC because they are meant to supply it to farther places, and AC can easily travel in wires over long distances. The same AC can be converted into DC when it is supposed to be stored in batteries.

Alongside advantages, AC has some severe disadvantages. AC is much more hazardous than one can imagine. The slightest problem and mistake can result in a deadly accident. AC cannot be used directly to charge batteries unless converted into DC by a rectifier. Since our major electrical appliances like refrigerators use AC, a problem with the current can damage these costly appliances.

What is DC Current?

DC refers to “direct current”. The main characteristic of this current is that it flows in a linear direction, and its voltage remains constant throughout the supply. The most common DC power source is built-in and externally attached batteries. Until now, very few appliances use DC power except those that work on batteries.

Although many devices are now shifting to DC, the importance of AC is still unneglectable. Most importantly, DC is power used by mobile phones to take supplies from the battery or power banks. Electrical engineers are planning to use DC to supply electricity to long distances by using the HVDC transmission.

DC has so far shown excellent compatibility with the latest power generation mechanisms like solar and wind. DC is also reliable in terms of voltage supply because it provides constant voltage. In this way, it reduces the probability of damage to appliances in case of voltage fluctuation.

The most considerable disadvantage of DC is that it requires several pieces of equipment like a rectifier and inverter if it is used to transmit electricity. Scientists are yet to anticipate the resolution of such drawbacks in DC, and it is said that DC will likely be the dominating current form soon.

Difference Between AC Current and DC Current

  1. AC moves in frequency, whereas DC moves with consistency
  2. AC is bidirectional, whereas DC is unidirectional
  3. AC is transmissible on long distances, whereas DC cannot be transmitted on long distances
  4. AC may not be the future, whereas DC entails a bright future
  5. AC is used commonly, whereas DC is limited in use

Comparison Table Between AC Current and DC Current

Parameters of ComparisonAC CurrentDC Current
Voltage SupplyThe voltage fluctuates as the electricity is suppliedThe voltage remains the same throughout the supply
DirectionAC moves in changing directions because its electrons move forward and backwardDC moves in a precisely linear direction keeping its voltage-flow constant
UsabilityAC has more usability in the present contextDC’s usage is limited in today’s devices
Transmission RoleHigherLower
Future ProspectsDecliningRising


  1. https://ieeexplore.ieee.org/abstract/document/1435677/
  2. https://ieeexplore.ieee.org/abstract/document/568248/