In today’s world, we are fully dependent on technology for almost everything. Most of our technology runs on electricity. The electricity in our homes comes in two types – AC & DC. Here is the difference between the two.
DC Currents vs AC Currents
The main difference between DC (Direct Current) and AC (Alternating Current) is that DC Currents flow consistently in one direction, whereas, in AC Currents, the direction of electrons keeps switching back and forth.
In DC Currents, the current flow is monodirectional – the current only flows in one direction and keeps flowing in that direction. Hence, the electrons also flow in one direction throughout, that is, the direction opposite to the flow of current.
In the case of alternating currents, the current flow direction keeps switching. While the net flow of current travels in one direction, the current keeps switching from forwards to backward and forwards again.
Therefore, the direction of the flow of electrons also keeps switching at regular intervals.
Comparison Table Between DC Currents and AC Currents
| Parameters of Comparison | DC Currents | AC Currents |
| Direction of Flow of Current | DC Currents flow in a single direction steadily. | Rotating Magnets are used in AC Currents that keep changing the direction of the current flow. |
| Magnetism of Currents | Steady magnetism ensures the flow of current in a single direction. | The frequency of Direct Currents is 0 Hz, that is, zero cycles per second. |
| Transfer between Long Distances | Transferring DC Currents over long distances leads to severe energy loss. | AC Currents are safe to travel between long distances and main electric power. |
| Frequency of Current | DC Current is used for household items such as batteries, flashlights, etc. | The frequency of Alternating Currents ranges between 50 to 60 Hz depending on the geographical location. |
| Use in Household Items | AC Currents can not be used in household items as there is no net electricity flow, and it damages the battery. | AC Currents can not be used in household items as there is no net electricity flow and it damages the battery. |
What are DC Currents?
DC – Direct Current is an electrical current in which the current direction flow is constant throughout.
The major use of direct current can be seen in our households to provide energy to electrical appliances and to charge batteries.
Alternating current cannot be used in household items. The current flowing in the forward direction is canceled out by the current flowing backward. Therefore, the net flow of electricity is zero. This also damages the battery.
The frequency of Direct Currents is zero Hertz – that is, zero cycles per second as the direction of current flow is constant throughout.
Thomas Edison is known to be a pioneer in the work and research of the direct current. He proposed a model for installing small, local power plants to power cities.
As there is a high amount of energy loss while transferring direct current over long distances, these plants must be within 1.5km of the end-user.
Direct current is generated through –
a) An AC generator equipped with a device called a Commutator.
b) A device called a rectifier that converts AC to DC
c) Batteries that generate DC through chemical energy.
What are AC Currents?
AC – Alternating current is a type of current in which the current flow direction switches back and forth at regular cycles/intervals.
While carrying direct current over long distances, a large amount of energy loss can be seen. Therefore, Alternating Current is used to transfer electricity over long distances. It can even transfer electricity between two cities while losing negligible power.
Due to this reason, alternating current is used to power houses and buildings. It also powers electric motors used in washing machines and refrigerators.
The alternating current frequency varies between 50 to 60 Hertz – 50-60 cycles a second.
The standard frequency of alternating current used in the United States is about 60 Hertz. Whereas in Europe and other parts of the world, the frequency remains about 50 Hertz.
Alternating current is represented as a sine wave on a graph.
Another advantage of alternating current is that it can easily be converted from lower to higher voltages or higher to lower voltages using a device called a transformer.
Nikola Tesla is a pioneer in the research of alternating current. Tesla’s work led to the creation of transformers.
Transformers can be used to step up the voltage to several thousand volts to allow for easier transportation. They could also later step down the voltage to allow for household usage.
Alternating current can be generated using a device known as an alternator.
Main Differences Between AC Currents and DC Currents
- The direction of current flow in direct current remains constant in a single direction. For Alternating Current, the direction keeps switching at regular intervals.
- The frequency of direct current is zero Hertz, whereas the frequency of alternating current is 50-60 Hz.
- Due to significant energy loss, direct current cannot be transferred over long distances. Therefore, alternating current is used for this purpose.
- Alternating current cannot be used in household items as there is no net flow of energy, and it damages the battery. Therefore, the use of DC is seen in batteries and household appliances.
- The graphical representation of direct current is a straight line, whereas it is a sine wave for alternating current.
Conclusion
Different kinds of electricity usage require different types of current flow – namely, Direct Current and Alternating Current. Research on these types of currents over the years has made our lives significantly easier.
The appropriate use of each current type in each situation allows our electrical gadgets to function smoothly.
References
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