Electricity is one of the important requirements that a human has after air and water. With the invention of electricity, life became much simpler than before. All the electronic devices, industries, houses, work stations, technology, run on electricity. There are two forms of energy and they are:
- Alternating current (AC)
- Direct current (DC)
What do these two forms of energy mean and how are they different from each other? The main difference between ac and dc is in terms of their working, constructions and applications.Â
What is alternating current?
Alternating current (AC) is defined as the flow of charges which change their direction periodically. Along with current, voltage level also reverses. AC finds application in delivering power to houses, work stations, industries.
How to generate AC?
An alternator is used for producing AC as it is designed for generating AC. A loop of wire is spun around the magnetic field for inducing current flow along the wire. The waveforms obtained while generating the current can be either sine, triangle, or square. Sine waves are the most preferred waveforms as they are easy to generate and calculate.Â
The mathematical form of the sine wave is given as:
| V(t) = Vp sin (2πft + Φ) |
 Where,
- V(t) is the function of time
- Vp is the amplitude
- 2π is a constant which converts frequency from Hertz to radians per second
- f is the sine wave frequency in Hertz
- t is the dependent value in seconds
- Φ is the phase of the sine wave
- sin () states the voltage in the form of a periodic sine wave
Applications of AC
Following are the application of AC:
- Household appliances such as refrigerators, dishwashers, etc use AC.
- Electric motors run on AC.
- AC power is used for generating and transmitting power over long distances.
What is direct current?
Direct current is defined as the flow of electric charges in unidirectional flow. The intensity of the current is dependent on the time and is independent of the direction of flow of electrons.Â
How to generate DC?
The movement of electrons is from the negative pole to the positive pole. Electrochemical cell, batteries, photovoltaic cells are the source of DC. AC is preferred over DC.
Summary of the difference between ac and dc:
| Parameter | Alternating current | Direct current |
| Direction | The direction is reversed when the flow is taking place in the circuit | The direction remains unchanged and one direction is maintained in the circuit |
| Power factor | For ac, it lies between 0 and 1 | For dc, it is always 1 |
| Source | AC generators and mains are the sources of generating alternating current | Battery and electrochemical cells are the sources of generating direct current |
| Types of waveforms | There are different varieties of waveforms that are obtained such as sine wave, triangular, square | The waveforms obtained are pure and pulsating |
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