Standard Definitions In Ac Circuits

STANDARD DEFINITIONS IN AC CIRCUITS

1. Instantaneous Value:

The valve of an alterna  instantaneous valves of an alternating e.m.f at the instants Hart, and t, respectively. 

2. Waveforms:

The graphical representation of instantaneous valves of an alternating quantity plotted against time is called its waveform.

3. Cycle:

Each repetition of a set of positive and negative instantaneous values of the alternating quantity is called a cycle.

Such repetitions occurs of regular interval of time. Such a waveform which exhibits variations that occur after a regular time interval is called periodic waveform.

One cycle corresponds to 2л radians or 360°.

4. Time Period:

The time taken by an alternating quantity to complete its one cycle is known as its time period denoted by T seconds.

5. Frequency:

The number of cycles completed by an alternating quantity per second is known as its frequency.

It is denoted by fand it is measured in cycles/second. or Hertz. vew one a 107

6. Amplitude:

The maximum value attained by an alternating quantity during positive or negative half cycle is called its amplitude. It is denoted by E_m or I_m

7. Angular Frequency:

It is the frequency expressed in electrical radians per second. As one cycle of an alternating quantity corresponds to 2л radians. The angular frequency can be expressed as (2 лx cycles/sec). It is denoted by 'o' and its unit is radians/second.

ω = 2лf radians/sec