We define the unit impulse as a function of time which is zero when its argument, generally (t-o), is less than zero; which is also zero when argument is greater than zero; which is infinite when its argument is zero; and which has unit area
Any periodic waveform f(t)f(t) can be expressed by a Fourier series provided that (1) If it is discontinuous, there are only a finite number of discontinuous in the period T (2)It has a finite average value over the period T (3)It has a finite number of positive and negative maximums in the period T
The readings of three watt-meters Ax =v an+lnx vBx=vbn+lnx vc=von+v Nx (UANia tUBvibB+Uvicdt+l(uN(ia tibB +ic)dt T Jo aNaA foBNLbB +Uvic)dt The sum of the average powers taking by the three-phase loads
Example 2: Find the three inductance appearing in the T equivalent of the transformer shown in Fig., if L2=4H and the input inductance at A-B is 6H with C-D open-circuited, and 2H with C-D short-circuited