An alternating quantity is one which reverses in direction repeatedly.
A cycle is a complete period of events, which then repeats itself. The time for one cycle is the periodic time or period, T. The number of complete cycles in one second is the frequency, f. The unit of frequency is the Hertz (Hz). Thus,
For a sinusoidal waveform (sine wave) r.m.s.
(root mean square) value of current is that current which will
have the same heating effect as a direct current of the same
value. is denoted by I, and unless stated the r.m.s.
value is always
assumed. , where
, is the peak or maximum value of current. The
peak-to-peak value will be twice the peak value, i.e.
.
A waveform can be said to lag, lead, or be in phase with another waveform. Unless otherwise stated, an AC waveform is assumed to be sinusoidal.
![]() Questions |
page (t07) |
Some material Copyright John Bowyer G4KGS. |
Click here for important Copyright information |
Web Space provided by Hostroute.com Ltd |
Contact details |