Problem 4.70(b): A full-wave bridge-rectifier circuit with a 0.6 kN2 load operates from a 120 V (rms) 60 Hz household supply through a 18-to-1 step-down transformer having a single secondary winding. It uses four diodes, each of which can be modeled to have a 0.7 V drop for any current. For what fraction of a cycle does the diodes conduct? Make your answer accurate up to two decimal digits and express the fraction as a percentage (i.e., between 0 and 100)