practice problem set - Northwestern Mechatronics Wiki

4. Approximately plot the current through the diode as a function of the voltage across the diode.II+ _Voltage-3V -2V -1V 1V 2V 3VIA 25. The switch in the circuit at right has been closed for along time, so that the circuit is in steady state. In all of youranswers, make sure that the sign of the current is2Hcorrect. All of your answers should be numbers with +Iproper units. Assume that the forward bias voltage1of the diode is 0.7 V.10 V_a. Give the steady-state current I 1 .b. Give the steady-state current I 2 .50Ωc. What is the energy in the inductor?d. The switch is now opened at t=0. What is I 1 theinstant after the switch is opened?e. At the instant after the switch is opened, what is I 2 ?f. At the instant after the switch is opened, give thevoltage at point A (referenced to ground).g. At the instant after the switch is opened, give the rate of change of I 1 (that is, dI 1 /dt).h. Plot the voltage across, and current through, the inductor as a function of time from t=0. The plots shouldclearly show the time constant.6. For the transistor below, the voltage from the base to the emitter is V BE when the transistor is on, andwhen the transistor is saturated, the voltage from the collector to the emitter is V CEsat . In the linear (active)mode, the transistor satisfies I C = β I B , where β is the transistor gain. Give the ranges of V in voltages forwhich the transistor is off and for which it is saturated.V sV inR 1R 2