A 60 Hz PWM inverter operates with a duty cycle of 2/3 from a 300 V DC supply. The AC load consists of a resistance of 30Ω in series with an inductance of 15mH. Determine the frequencies and the r.m.s. values of the two lowest-order harmonics in the △C load current that exist. Hint: Find voltage harmonics and then use Ohm's law through the load.