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Concept of AC and DC Current , Alternating , Direct , Example

In this article you will see about concept of AC ( Alternating Current ) and also concept of DC ( Direct Current ) Now days electricity is generated as AC (alternating current). The power generated is transmitted, distributed and mostly used as AC. In this article, the fundamental concepts of AC and AC circuits are discussed below.


We have determined that the electric current drawn from a battery is unidirectional.The polarity of the battery is marked + Ve and - Ve. When a particular load, called a lamp (denoted by its resistance) is connected to the two terminals of the battery, a current flows through the lamp in a particular direction.

constant or constant-value direct current

Along with the current, its direction also remains constant with respect to the time constant of the battery voltage. Such a current is known as a constant or constant-value direct current.

Definition of direct current 

A direct current is a unidirectional flow electric charge. An electrical cell is a major example of DC power. 

Direct current can flow 
  • Through a conductor as a wire .
  • It can also flow through an electron .
  • It flow through ion beam .
  • through a semiconductor.
  • It can also flow through insulator, or even vacuum as in electron or ion beams.
One question may comes in your mind that "Are batteries AC or DC?"

Answer of this question is battery is Direct Current (DC).By using dc to ac to dc converter which is known as inverter.

Q.Which is dangerous between AC and DC?
Answer : Alternating current is more dangerous than direct current .It is said that ac is four to five time even some cases 10 time more dangerous than dc 

Concept of AC and DC

When the direction of current is continuously changed through a circuit, such current is called (ac) alternating current.The polarity of the AC supply source changes alternately and alternately flows the current through the load associated with the terminals.
DC flowing through the load
  • DC flowing through the load : Shows the DC flowing through the load when connected at the battery terminals. Since the magnitude is assumed to be constant, it is represented through a graph as shown in the figure below.

diagram DC flowing through the load
  • Direct current of constant magnitude :In given figure below shows the nature of current. when the switch is 'ON' and 'OFF' at regular intervals.

direct current of variable magnitude
Using the reverse switching arrangement, as shown in the diagram, we can flow an AC through the load.
                              a battery connected to a resistive load through a reversing switch

Here, through a reverse switch, supply terminal 1 is connected to load terminal 2 to and supply terminal 2 is connected to load terminal 1 terminal.

                         alternating current of square–wave shape

It may be noted that if the period of the current in both directions is constant, the load current will be alternating in nature and its wave shape will be square or rectangular type as shown in the figure below.

                          alternating current of rectangular wave shape


I hope you like like this information about concept of AC and DC in details .If you have any question regarding this topic you can ask by commenting us . 


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