Question

For the trapezoidal current wave-form of Fig., determine the effective value.

Answer 1

For 0 < t < 3T/20, equation of the current can be found from the relation

i/t = I_m/3T/20 or i = 20I_m/3T x t

When 3T/20 < t < 7T/20, equation of the current is given by i = I_m. Keeping in mind the fact that ΔOAB is identical with ΔCDE,

RMS value of current

Incidentally, the average value is given by