A dc motor is driven from a chopper with a source voltage of 24V dc and at a frequency of 1 kHz. Determine the variation in duty cycle required to have a speed variation of 0 to 1 p.u. delivering a constant 2 p.u. load. The motor details are as follows: 1 hp, 10V, 2500 rpm, 78.5 % efficiency, Ra=.01 O, La=.002 H, Kb= .03819 V/rad/sec. The chopper is one quadrant, and the on-state voltage drop across the device is assumed to be 1V regardless of the current variation.