Homework #4 Solution
October 27, 2011
Point Distribution of Homework #4 (55 points total)
Basic rule:
1. All calculation mistakes get 1 point o.
2. Mistakes in setting up necessary equations such as KCL get 1 point o if KCL is applied at the right
nodes.

E40
Autumn 2011
Homework 1
Due 5:00 pm, Wednesday, October 5, 2011
Please write your Name and Lab Section Time on the front page.
1. The current i(t) in a wire is given by: i(t) = (1.5A)sin[(2)(1000)t], where t is in seconds.
a) Plot the current from t =

E40
Autumn 2011
Homework 2
Due 5:00 pm, Wednesday, October 12, 2010
Please write your Name and Lab Section Time on the front page.
1. Solving circuits using Kirchhoffs Current Law.
a)
b)
c)
d)
e)
f)
Apply Kirchhoffs current law at node a.
Apply Kirchhoffs

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Problem 4.17
Determine vo across the 10-k resistor in the circuit of Fig. P4.17.
2 k
_
1V
+
in = 0
_
vn
vp
ip = 0
50
10 k
+
5V
vo
+
_
Figure P4.17: Circuit for Problem 4.17.
Solution: Since ip = 0, there is no voltage drop across the 2-k re

E40
Autumn 2011
Homework 3
Due 5:00 pm, Wednesday, October 19, 2011
Please write your Name and Lab Section Time on the front page.
1. This circuit has a light-emitting diode (LED) being powered by a 9 V battery; the 25
series resistance models the intern

E40
Autumn 2011
Homework 4
Due 5:00 pm, Wednesday, October 26, 2011
Please write your Name and Lab Section Time on the front page.
1. U&M 4.20. Since the op amps negative supply voltage isnt specified, assume that it is
-12 V. Use ideal op-amp analysis.
2

E40
Autumn 2011
Homework 5
Due 5:00 pm, Wednesday, November 9, 2011
Please write your Name and Lab Section Time on the front page.
1. The voltage waveform vs(t) steps down at t = 0.
(a) What is iR(t = 0-) in mA? What is iR(t = 0+) in mA?
(b) What is vR(t