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The movement of charged particles or atoms through a conductor or space is called current. The S.I unit is called Ampere.
Current is generally of two types – DC and AC.
A direct current is a type of current that flows or moves only in one direction. Alternating current changes its direction or flow of current over time.
In this article, we are going to study alternating current.
Alternating Current
AC represents alternating current. An alternating current is a type of current that changes its direction, polarity and magnitude over an interval of time. Physicist Nikola Tesla invented the AC current in the late 1900s.
AC plots a sine wave. It can also be described as a curved line. They represent electric cycles. They are measured in hertz or Hz.
We can transform AC into DC by using a rectifier. We can also convert direct current into AC by using an inverter.
AC is used to supply power to offices, houses and office buildings.
What is the peak value of alternating current?
The maximum value an alternating current reaches in one cycle is called its peak value. This value is also known as the maximum value, amplitude value or crest value.
The average value is the average of all the spontaneous values of current and alternating voltage in one complete cycle.
The quantity of DC current, which flows through the same heating effect through the same resistance for the same interval of time, is known as the RMS or effective value.
The RMS value is the square root of mean squares of spontaneous values.
Properties of Alternating Current
It reverses its direction after some time.
Frequency – the number of cycles a current travels in one second(f). The unit of frequency is hertz. Its frequency is generally between 50 Hz to 60 Hz. Mainly its frequency depends on your country.
AC travels very long distances without losing its electric power. It can transfer between cities.
By using transformers, we can easily convert AC to and from high voltages.
AC powers electric motors. It is also used in household appliances such as dishwashers and refrigerators.
The voltage of AC circuits changes periodically.
It can be easily converted into DC by using rectifiers.
In AC, electrons change their direction (frontward to backward).
The AC current is in sinusoidal form. Other types are triangular and square trapezoidal.
In AC, the chances of losing energy during transmission are very low.
Merits of AC
It has a low maintenance cost.
It provides better safety.
It is easy to interrupt the AC with a circuit breaker because the current goes back to zero automatically every ½ cycle.
It provides better safety.
We can step up or step down the AC voltage amplitude.
The transmission losses are less when AC is supplied at higher voltages as compared to DC.
It is easy to generate when compared to DC current.
Demerits of AC
It causes power problems.
It has a comparatively high installation cost.
It can not be used for charging batteries and in electroplating and electric traction.
Conclusion
An alternating current is a type of current that changes its direction, polarity and magnitude over an interval of time. In this article, we learned about alternating current. Then, we also discussed the properties of the AC current. We also studied about the merits and demerits of the AC current. This is a very crucial topic for physics students and students appearing in board exams. This topic is also helpful for students or aspirants appearing in IIT/JEE/NEET exams.
