Download Thevenin and Norton equivalents

Lecture 4
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Complex impedance
Thevenin and Norton
bode plots
decibels
What’s the impedance of a short piece
of thick wire?
A) Very large and mostly real
B) Very large and mostly complex
C) Very large but can be complex and/or real
D) About zero
E) Can’t tell with the given information
What is inside the power supply?
A)Lots of wire
B) An ideal voltage source and some R
C) An ideal current source and some R
D)A complex circuit to understand…
E) No idea
What is inside the power supply?
Answer: A complex circuit to understand…
That can be modeled as an ideal voltage source and some R
OR, as an ideal current source and some R
For any combination of simple voltages and
linear resistors, you can find an equivalent
circuit composed of a single voltage source and
a single equivalent resistor, that will produce
the same current (and voltage) through RL.
(AND Vth and Rth are independent. of RL.)
B5
To measure the current thru resistor 3, how should
the ammeter be attached?
a)
d)
1
A
3
A
A
4
A
b)
12 V
2
c)
e) MORE than one of these choices is ok.
B6
An ideal ammeter should have
A)
B)
C)
D)
Zero resistance
Infinite resistance
A well defined resistance > 0 (e.g. 1 or 1k)
Shiny red color
B7
To measure the voltage across resistor 3, how should the
voltmeter be attached (assume you only attach one at a time)?
a)
d)
1
V
3
V
V
4
V
b)
12 V
2
c)
e) MORE than one of these choices is ok.
B8
An ideal voltmeter should have
A)
B)
C)
D)
Zero resistance
Infinite resistance
A well defined resistance >0 (e.g. 1 or 1k)
Shiny red color
What’s the magnitude (i.e. ‘modulus’) of
the impedance of a good voltmeter?
A) Very large
B) Very small
C) Doesn’t matter. Could be either, large or small.
What’s the magnitude (i.e. ‘modulus’) of
the impedance of a good ammeter?
A) Very large
B) Very small
C) Doesn’t matter. Could be either.
What’s the magnitude (i.e. ‘modulus’) of
the impedance of a good voltage source?
A) Very large
B) Very small
C) Doesn’t matter. Could be either.