through n 9. (c) Determine the modulation index. Question 6 (Cycloconverter) The input voltage to 1-0/10 bridge type cycloconverter is 120 V 60 Hz. The load resistance is 2.502, and the load inductance is 40 mH. The frequency of output voltage is 20 Hz. If the delay angle of thyristors is ap 2π/4, determine: (a) the RMS output voltage; (b) RMS current of each thyristor; (c) the input power factor; (d) draw the waveforms; and (e) Repeat the previous steps for L-0. Question 7 (DC motor drives) = The speed of separately excited motor is controlled by a 1-0 semiconverter. The field current is also controlled by a semiconverter and the field current is set to the maximum possible value. The AC supply voltage to the armature and field converter is one phase, 208 V, 60 Hz. The armature resistance Ra 0.122, the field resistance R22002, and the motor voltage constant is K, 1.055 V/A-rad/s. The load torque is T. 75 N.m at a speed of 700 rpm. The viscous friction and no-load losses aer negligible. Determine: (a) the field current; (b) delay angle of the converter in the armature circuit; and (c) input power factor of the armature circuit. Question 8 (Induction motor drives) A 3-0 56-kW, 3560-rpm 460-V 60-Hz two-pole Y-connected induction motor has the parameters; R, = 0, R, = 0.182, X, = 0.132, X, = 0.202, and Xm = 11.402. The motor is controlled by a constant volts/hertz ratio corresponding to the rated voltage and rated frequency. (a) Give the possible circuit arrangments to realizing this type of control. (b) Calculate the maximum torque and the corresponding speed for (i) 60 Hz and (ii) 30 Hz.