Fig. $$(a)$$ shows an inverter circuit with a $$dc$$ source voltage $${V_{s}}$$. The semiconductor switches of the inverter are operated in such a manner that the pole voltages $${V_{10}}$$ and $${V_{20}}$$ are as shown in fig.
Fig. $$(b).$$ What is the rms value of the pole-to-pole voltage $${V_{12}}$$:

A single - phase full-bridge voltage source inverter feeds a purely inductive load, as shown in figure. when $${T_1},{T_2},\,\,\,\,\,{T_3},{T_4}$$ are power transistors and $${D_1},{D_2},\,{D_3},{D_4}$$ are feedback diodes. The inverter is operated in square-wave mode with a frequency of $$50$$ $$Hz.$$ If the average load current is zero, what is the time duration of conduction of each feedback diode in a cycle?

A three phase voltage source inverter supplies a purely inductive three phase load. Upon Fourier analysis, the output voltage waveform is found to have an $${h^{th}}$$ order harmonic of magnitude α h times that of the fundamental frequency component $$\left( {{\alpha _h} < 1} \right),$$ the load current would then have an $${h^{th}}$$ order harmonic of magnitude