ECEN3714 16 February
2006 Exam #1
1) [25] Given the circuit shown, if vin(t) = e-3t,
find vout(t). [Answer:
0.9884e-3t + 0.1250cos(0.378t + 82.82 degrees)]
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2) [15] Find L{ d/dt te-4t}. (Hint:
Use the tables in Chapter 12.) [s/(s+4)2]
3) [10] Find L{t sin(5t)}. (Hint: Use the tables in
Chapter 12.) [10s/(s2+25)2]
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4) Find the Laplace transform of x(t). Vpeak = + 1
volt. [4pi(1-e-s)/(s2+16pi2)]
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5) [25] If vin(t) = u(t), find the current through the 10
ohm resistor. [100ma,
heading from top to bottom]
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