For the circuit of a full bridge single phase inverter, a. How many controlled pulses are needed over a half cycle of the output voltage to obtain 70% of Vac,max and, at the same time, eliminate the 5th and 7th harmonics? B. Compute the parameters of the pulse width if Vac is controlled to 70% of its maximum and the 5th harmonic eliminated. C. Sketch the waveform of AC output voltage for case b).