Circuits (1) Final Exam
The Hashemite University Electrical Engineering Department Date: May,19th, 2012
Exam Duration: 2 hours
1) For the circuit of Figure 1, the switch has been closed for a long time then opened at t = 0 . 1.1. The value of the current through the inductor I L (t = 0) is: …………………………………………………………………………………………………………………………………………. …………………………………………………………………………………………………………………………………………. …………………………………………………………………………………………………………………………………………. ………………………………………………………………………………………………………………………………………….
1.2. The value of the voltage across the inductor V L (t = −4ms ) is: …………………………………………………………………………………………………………………………………………. ………………………………………………………………………………………………………………………………………….
1.3. The value of the voltage across the inductor V L (t = 0.1 ms ) is: …………………………………………………………………………………………………………………………………………. …………………………………………………………………………………………………………………………………………. …………………………………………………………………………………………………………………………………………. ………………………………………………………………………………………………………………………………………….
1.4. The value of the current I R (t = −0.1 ms ) is: …………………………………………………………………………………………………………………………………………. …………………………………………………………………………………………………………………………………………. ………………………………………………………………………………………………………………………………………….
1.5. The value of the current I R (t = 0.1 ms ) is: …………………………………………………………………………………………………………………………………………. …………………………………………………………………………………………………………………………………………. ………………………………………………………………………………………………………………………………………….
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2) For the circuit of Figure 2, the switch has been opened for a long time before it is closed at t = 0 . Answer the following questions: 2.1. The value of the damping coefficient α equals: ………………….……………………..…… …………………………………………………………………………………………………….…… …………………………………………………………………………………………………….……
2.2. The value of the resonance frequency ω 0 equals: ………………….……………………..…… …………………………………………………………………………………………………….…… …………………………………………………………………………………………………….……
2.3. The damping type of the RLC circuit is: ………………….……………………………………… 2.4. The two solutions of the circuit (S1, S2) are: …………………………………………………… …………………………………………………………………………………………………….…… …………………………………………………………………………………………………….……
2.5. The value of VC (t = 0) equals: ………………………….……….……………………………………… …………………………………………………………………………………………………….…… …………………………………………………………………………………………………….……
2.6. The value of I L (t = 0) equals: ………………………….……….……………………………………… …………………………………………………………………………………………………….…… …………………………………………………………………………………………………….……
2.7. The expression of VC (t ) for t ≥ 0 is: ………………………….……….………………………….…… …………………………………………………………………………………………………….…… …………………………………………………………………………………………………….…… …………………………………………………………………………………………………….…… …………………………………………………………………………………………………….…… …………………………………………………………………………………………………….…… …………………………………………………………………………………………………….…… …………………………………………………………………………………………………….…… …………………………………………………………………………………………………….……
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3) For the circuit of Figure 3, the switch has been opened for a long time before it is closed at t = 0 . Answer the following questions 3.1. The capacitor voltage VC (t → −∞ ) equals: ………………………………………………………………………………………………………………………….…… ………………………………………………………………………………………………………………………….…… ………………………………………………………………………………………………………………………….……
3.2. The capacitor voltage VC (t → ∞ ) equals:
………………………………………………………………………………………………………………………….…… ………………………………………………………………………………………………………………………….…… ………………………………………………………………………………………………………………………….……
3.3. The capacitor voltage VC (t = 0 + ) equals:
……………………………………………………………………………………………………………………….…… ………………………………………………………………………………………………………………………….…… ………………………………………………………………………………………………………………………….……
3.4. The capacitor current I C (t = 0 + ) equals:
………………………………………………………………………………………………………………………….…… ………………………………………………………………………………………………………………………….…… ………………………………………………………………………………………………………………………….……
3.5. The capacitor current I C (t = 0 − ) equals:
………………………………………………………………………………………………………………………….…… ………………………………………………………………………………………………………………………….…… ………………………………………………………………………………………………………………………….……
3.6. The capacitor current I C (t → ∞ ) equals:
………………………………………………………………………………………………………………………….…… ………………………………………………………………………………………………………………………….…… ………………………………………………………………………………………………………………………….……
3.7. The energy stored in the capacitor at t = ∞ equals: ………………………………………………………………………………………………………………………….…… ………………………………………………………………………………………………………………………….…… ………………………………………………………………………………………………………………………….……
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4) The current I(t) flowing through the network in Figure. 4(a) is shown in Figure. 4.(b) 4.1. The voltage V(t) at 25 ms is: ………………………………………………………………………………………………………………………….…… ………………………………………………………………………………………………………………………….……
4.2. The voltage V(t) at 35 ms is: ………………………………………………………………………………………………………………………….…… ………………………………………………………………………………………………………………………….……
4.3. The energy stored in the equivalent inductor at t = 25 ms is: ………………………………………………………………………………………………………………………….…… ………………………………………………………………………………………………………………………….……
With all best wishes
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End of Exam
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The solution From ::: Motaz Abu-Sbietan ^__^
