Difference Between Alternating Current (AC) & Direct Current (DC)

The conducting materials have free electrons which move from one atom to another when the potential difference is applied across them. This flow of electrons in a closed circuit is called current. On the basis of the direction of movement of electrons in a closed circuit, the electric current is mainly classified into two types, i.e., the alternating current and the direct current.

One of the major differences between the alternating and direct current is that in alternating current the polarity and the magnitude of the current changes at the regular interval of time whereas in direct current it remains constants. Some of the differences are explained below in the form of the comparison chart by considering the various factors;

Content: Alternating Current (AC) Vs Direct Current (DC)

1. Comparison Chart
2. Definition
3. Key Differences
4. Point to Remember

Comparison Chart

Basis	Alternating current	Direct current
Definition	The direction of the current reverse periodically.	The direction of the current remain same.
Causes of flow of electrons	Rotating a coil in a uniform magnetic field or rotating a uniform magnetic field within a stationary coil	Constant magnetic field across the wire
Frequency	50 or 60 Hertz	Zero
Direction of flow of electrons.	Bidirectional	Unidirectional
Power Factor	Lies between 0 and 1	Always 1
Polarity	It has polarity (+, -)	Do not have polarity
Obtained From	Alternators	Generators, battery, solar cell, etc.
Type of load	Their load is resistive, inductive or capacitive.	Their load is usually resistive in nature.
Graphical Representation	It is represented by irregular waves like triangular wave, square wave, square tooth wave, sine wave.	It is represented by the straight line.
Transmission	Can be transmitted over long distance with some losses.	It can be transmitted over very long distance with negligible losses.
Convertible	Easily convert into direct current	Easily convert into alternating current
Substation	Few substation is required for generation and transmission	More substations are required for generation and transmission
Passive Parameter	Impedance	Resistance
Harazdous	Dangerous	Very dangerous
Application	Factories, Industries and for the domestic purposes.	Electroplating, Electrolysis, Electronic Equipment etc.

Definition of Alternating Current

The current which changes its directions periodically, such type of current is called alternating current. Their magnitude and polarity also change along with the time. In such types of current, the free electrons (electric charge) moved in the forward as well as in the backwards direction.

The frequency (number of cycles completed in one second) of the alternating current is 50 to 60 Hz depends on the country. The alternating current is easily converted from the high value to low value and vice versa with the help of the transformer. Thus, it is mainly used for transmission and distribution.

Definition of Direct Current

When the electric charge inside the conductor flows in one direction, then such type of current is called direct current. The magnitude of the direct current always remains constant and the frequency of the current is zero. It is used in cell phones, electric vehicles, welding, electronic equipment, etc.

The graphical representation of the alternating current is shown in the figure below.

Point to Remember

The direct current is more dangerous than the alternating current. In alternating current, the magnitude of the current becomes high and low at regular interval of time and in direct current, the magnitude remains the same. When the human body is getting shocked, the alternating current enter and exit from the body at regular time interval whereas the direct current, afflict the body continuously.