Question

QUESTION Cyril the Circuit Analyst is examining the interaction of both AC and DC sources with a circuit. The circuit is drawn below. Pay careful attention to the arrows on the switches which show which are initially open, and which are initially closed. Assume that the capacitor is initially discharged at 0. All times are in seconds 10 mH 1-Os1-1s!=2s \ t = 5s 400 | 10cos(ox) 50 pF 10 mA At 0, the first switch closes connecting the current source to the capacitor. Find the (a) voltage on the capacitor at1 second. (7 marks) At r 1, the second switch opens disconnecting the current source from the capacitor Find the voltage on the capacitor at t = 2 seconds. (b) (2 marks) 2, the third switch closes connecting the capacitor to the resistor. Find the voltage (c) At on the capacitor at t=2.1 seconds. (8 marks) (d) Att-5, the fourth switch closes connecting the AC source and inductor. The circuit reaches AC steady state at some t>> 5. Express the AC steady state voltage on the capacitor as a function of time using o- 1000 rad/s (15 marks) Perform frequency response analysis for the circuit for t>>5 to calculate the gain in dB and phase in degrees for w at 100 rad/s, 1000 rad/s and 10000 rad/s. (e) (15 marks) (f) Plot the response calculated in part (c) in a Bode plot. (3 marks)

Answer 1

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