Download Homework #2 with Solutions - Basic Electric Circuit Theory | ENEE 204 and more Assignments Electrical and Electronics Engineering in PDF only on Docsity! ENEE 204 Fall 2008 HW #2 Due: in class Thursday, Sept. 18, 2008
Prof. Gomez
Reading: Mayergoyz and Lawson, Sections 2-2.5, Download and study Lectures 3&4.
1. Circuit branches, nodes and meshes. Consider circuit in Figure P2-3 in the text
with the additional information that the voltage supply Vs is given, as well as the
values of the circuit components.
a. How many branches? How many nodes? How any trivial nodes? How
many meshes? Llow many trivial meshes?
. How many unknowns does this circuit have? Assign them.
Write down KCL for each node.
Write down KVL for each mesh.
Write down the terminal relations for all the components.
How many total equations do you have? Is it equal, more or less than.
the number of unknowns?
Show that not all KCL. equations are linearly independent.
moan
2. Solving circuit equations involving resistors. Consider circuit below.
a
b.
c
d.
e
f.
Write down and label all the unknown quantities.
Using the convention for reference directions, label the signs of the terminals.
Write down KVL for all meshes.
Write down KCL for all nodes EXCEPT the bottom Goining Vs, R2, R6).
Write down the tenninal relations for all components.
Salve for all unknown quantities using the equations from c-e.
3. Solving circuit equations involving resistors using process of successive
simptification. Again consider circuit 1.
a.
b.
By using successive simplification of the series and parallel connections, draw
a circuit with one voltage source and one resistor that represents the entire
circuit, Calculate the current and voltage across the resistor.
Successively expand the circuit while calculating the currents and voltages for
each step. Show that this method gives exact same result as in Problem 2.
4. Circuit equations for capacitive and resistive elements, Using KVL.KCL and
terminal relations in the figure below, show that the differential equation for the
voltage on the capacitor is given by
1 1
Hp
¥,
ly, = ee
RC} SRC
5, Ideal and non-deal (‘real’) voltage sources. An ideal voltage source is one that
provides a constant voltage (Vo), regardless of the load resistance(R;) connected
in series to il, This means that the ideal battery has NO internal resistance. A real
battery however can be modeled by an ideal voltage source (Vo) in series with an
_internal resistance Rj. Given the followin:
g vollage versus current relationship.
Current
. 9
10 133A
5 4,664
a. Determine Yoo and R; for this real voltage source.
b. If you connect this to a load resistance Ri =100Q in series, what is the power
on Ry?
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