Alternating Current

 

Alternating current

 A current that continuously fluctuates in amplitude over time and periodically reverses in direction is known as alternating current OR when compared to direct current (DC), which only travels in one direction and cannot sporadically shift, alternating current (AC) is an electric current that periodically flips direction. Its value is determined at any time by:

V= Vmsinωt

I= Imsinωt

          Where, Vm and Im is the peak value of voltage and current graph.

Properties of AC current

>It includes both positive and negative values.

v  > The time taken to complete one cycle is known as periodic time.

v  > Area of positive cycle = area of negative cycle.

v >  Average value of emf in omh cycle is always zero.

RMS (Root-Mean-Square) of an alternating current

RMS, or the Root-Mean-Square of current values, is an acronym. RMS value of alternating current is equal to the amount of DC current which produces the same heating effect flowing through the same resistance during the same time. Direct current that passes through a resistance to get the alternating current's RMS value. AC has a higher RMS value than the average. The area covered over a half-cycle can be used to calculate the RMS value of a sine current wave. This holds true for all waves, including symmetrical and asymmetrical as well as sinusoidal and non-sinusoidal ones. With Irms or Iv, it is identified. It is represented by Irms.

NOTE: Ammeter reading is the rms value of ac

Average Value of an Alternating Current

The value of DC that would allow the circuit to carry the same amount of charge for half as long as the average value of AC does is known as the average value of AC (sinusoidal voltage or current).

An average cycle value for sinusoidal alternating voltage or current is zero. This occurs as a result of the positive and negative half cycles' regions being equally spaced from one another. Whether it is positive or negative during a half-cycle, the average number is not zero. The average of a sinusoidal voltage or current is thus equal to the average of a half cycle.

It is given by;