Q2. Experimental data from a stable open-loop system result in the frequency response shown in the Nyquist plot below. Imag 0.8 0.6 F0.4 0.2 Re -1.0 -0.8 -0.6 -0.4 -0.2 0.2 0,4 0.6 0.8 E-0.2 E-0.4 0.6 -0.8 (a) Show that the closed-loop system with unity negative feedback is also stable. (b) Comment on the stability if the magnitude is increased by 20DB (a factor of 10).

The figure shows three wires with equal currents and four Amperian loops (dashed closed paths). Rank the loops in increasing magnitude (absolute value) of OB•di . A. 3<1=4<2 B. 1<2=3<4 C. 3<2<1=4 D. 4<1<2< 3 E. 4<2= 3<1

2. What is the capacitive reactance of a 0.10 µF capacitor at a 100HZ audio frequency and at a 100MHZ FM-radio frequency?

4. The following data are obtained for a Cu-Ni-Fe alloy during the generation of a steady-state ferromagnetic hysteresis loop. a. Plot the data b. What is the remanent induction? c. What is the coercive field? H (amperes/m) B (weber/m?) 0.65 (saturation point) 6 x 104 1 x 104 0.58 0.56 - 1 x 104 - 2 x 104 - 3 x 104 - 4 x 104 - 5 x 104 0.53 0.46 0.30 - 0.44 6 x 104 - 0.65