Electric Circuits I: ELCT 301 Final Exam (03 January 2018)eee.guc.edu.eg/Courses/Electronics/ELCT301...
Transcript of Electric Circuits I: ELCT 301 Final Exam (03 January 2018)eee.guc.edu.eg/Courses/Electronics/ELCT301...
Midterm Exam Electric Circuits I “ELCT 301” Time allowed: 2 hours
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Faculty of Information Engineering & Technology (IET)
Electronics Engineering Dept.
Electric Circuits I: ELCT 301
Final Exam (03 January 2018)
Course Instructors: Prof. Dr. Eng. Tarek Abdelsalam
Prof. Dr. Eng. Yasser G. Hegazy
Instructions:
1. Answer all the questions.
2. The exam consists of 6 questions in 13 pages including this page.
3. The exam allowed time is 3 hours.
4. Electronic Calculators are allowed.
5. Clearly show all steps used in your solutions.
Please, do not write anything on this page
Total 6 5 4 3 2 1 Question
Mark
58 10 8 10 8 10 12 Out of
Bar Code
Midterm Exam Electric Circuits I “ELCT 301” Time allowed: 2 hours
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Question # 1 [12 Marks]
The switch in the circuit shown in Figure 1 has been on position A for a long time. At t = 0 the
switch moves to position B.
a) Find the initial values of the inductor current iL(t) and the capacitor voltage V(t) at t=0
b) Find the final value of the inductor current and the capacitor voltage when the switch stays
on position B for a long time
c) Write down the mathematical expression for iL(t) for t ≥ 0.
d) Write down the mathematical expression for i(t) for t > 0
Figure 1
Midterm Exam Electric Circuits I “ELCT 301” Time allowed: 2 hours
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Question # 2 [10 Marks]
For the circuit shown in Figure 2:
a) Formulate the mesh current equations [ 7 Marks ]
b) Calculate the power supplied by the dependent source. [ 3 Marks ]
Figure 2
Midterm Exam Electric Circuits I “ELCT 301” Time allowed: 2 hours
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Question # 3 [ 8 Marks ]
a) Find the value of the resistance R in the circuit of Figure 3(a) that will result in maximum
power dissipation in the 8 resistor. [2 Marks]
Figure 3 (a)
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b) The relationship between the terminal voltage V and the current i of the linear and active
circuit is represented by the straight line where V in volts and i in Ampere as shown in
Figure 3(b). Find Thevenin equivalent circuit for the linear and active circuit [3 Marks]
Figure 3 (b)
Midterm Exam Electric Circuits I “ELCT 301” Time allowed: 2 hours
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c) For the circuit shown in Figure 3(c), find the potential difference between the two nodes a
and b [3 Marks]
Figure 3 (c)
Midterm Exam Electric Circuits I “ELCT 301” Time allowed: 2 hours
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Question # 4 For the circuit in Figure 4, what resistor connected across terminals a-b will absorb maximum
power from the circuit? What is that power? [ 10 Marks ]
Figure 4
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Question # 5 [8 Marks]
For the circuit in Figure 5,
a) Obtain the equivalent capacitance. [ 2 Marks ]
b) Find the voltage across the 80 F capacitor, [ 4 Marks ]
c) Calculate the energy stored in the 20 F capacitor. [ 2 Marks ]
Figure 5
Midterm Exam Electric Circuits I “ELCT 301” Time allowed: 2 hours
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Question # 6 [10 Marks]
For the circuit shown in Figure 6,
a) Write down the node-voltage equations [ 7 Marks ]
b) If the relationship between the output voltage V0 and the supply voltage VS is given by:
V0 = K VS. Find the value of K [ 3 Marks ]
Figure 6