1. In the circuit shown below, the switch closes at time t = 0. a) Find

PRACTICE EXAM 4
1250
F 14
1.
2.
In the circuit shown below, the switch closes at time t = 0.
a)
Find the time constant for the circuit.
b)
Write a numerical expression for vC(t) for t > 0 in the above circuit. Note:
vC(t = 0) = 0 V.
c)
At what time is the energy stored on the capacitor, wC, equal to 10 µJ?
Express the value of the following sum in rectangular form:
3.
a)
Draw a frequency-domain model of the above circuit. Label all components
and the current measurement with numerical values.
b)
Write a numerical expression for i(t).
4.
Write a MATLAB function that makes a phasor plot of the sum of entries in an array,
(in this case, the array is called Vphasors).
An example of how the function would be used and the plot it would produce is as
follows:
>> Vphasors = [6*exp(j*pi/6), 3*j, 1+3*sqrt(3)];
>> phasor_plot(Vphasors)
The individual vectors are shown in cyan, and the sum is shown in red.