Sp08 ECE331 Homework #1 Solution
1. The n quantum number designates the electron shell. The l quantum number designates the electron subshell. The ml quantum number designates the number of electron states in each electron subshell. The ms quantum number
ECE 331: Midterm II, May 5, 2008
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ECE331 Homework #7 Solution
1.
This problem asks us to consider a specimen of ice I which is at 15C and 10 atm pressure.
(a) In order to determine the pressure at which melting occurs at this temperature, we move
vertically at this temperature until we c
ECE331 Homework #6 Solution 1. (a) Since n0 < ni, so this is the minority carrier concentration. This is a ptype semiconductor. (b) The minority carrier concentration n0 = 4.5104 cm3. The majority carrier concentration p0, ni 2 (1.5 1010 ) 2 p0 = = = 5.
ECE331 Homework #5 Solution
1. Streetman, 3.2
The probability that a state at E above Ef is occupied is
f ( E f + E ) = 1 1 = 1 + exp( E f + E  E f ) / kT ) 1 + exp(E / kT )
The probability that a state at E below Ef is empty is
1  f ( E f  E ) = 1  1
ECE331 Homework #4 Solution 1. Explain the concept of electron effective mass. At what scenario the effective mass is the actual electron mass? Use equations if necessary. Effective mass is the term used to describe the total effect of forces outside and
ECE331 HW#3 Solution 1. (a) h h 6.63 10 34 kg * m p x = = = = 1.06 10  24 10 x 2x 2 1 10 s (b) 1 h h 4.14 10 15 t = = = = 6.59 10 16 2 (1) s E 2E
(
)
2)
E=
1 mv 2 19 2 , 1eV = 1.6 10
h = mv h m 2E m = h 2 Em = 6.63 10 34 2 9.11 10 31 E
 1 2
=
= 4
ECE331 Homework #2 Solutions
1. Direction A is a [ 1 10] direction Direction B is a [121] direction Direction C is a [0 1 2 ] direction Direction D is a [12 1] direction
2. For plane A this is a ( 1 10) plane. For plane B, this is a (122) plane.
3. (a) (1
ECE301 Homework #11
149 (solution)
Using node analysis first at Node A
1 1
VB V2
C1s + + VA = C1sV1
R2 R1
R2 R1
VA
1
+ C2 s + VB C2 s V2 = 0
Node B:
R2
R2
The ideal OP AMP model requires VB = VN = VP = 0 and I N = I P = 0 and these equations
reduce
ECE301 Homework#10
1230 (Solution)
R
IA
i1(t)
+
IB
C
L
V2(t)

Mesh Current Analysis
I A = I1 ( s )
I1 ( s )
1
1
sC
I B R + sL +
= 0 IB =
I1 ( s )
sC
sC
R + sL + 1
sC
s I (s)
L I (s)
L I (s)
s
C1
C1
C1
V2 ( s ) = sLI B ( s ) =
=
=
2
R
1
2
R + sL + 1
sR
ECE 301 Homework#9
126 (Solution)
VN
R
R
IN
VP IP
+
V2(t)
+
+
V1(t)
C
R
Using node analysis
VN VN V2
+
+ IN
R
R
=0
=0
(1)
VP
+ (VP V1 ) sC + I P
R
=0
=0
(2)
where I N = I P = 0, VP = VN
From (1)(2)
2VN V2
V
VV
= VN = 2 2 + 2 sC = sC V1
2
2R 2
R
R
1
V2
ECE301 Homework #8
11.61 (solution)
(a)
1
1
1
R
2
V2 ( s )
= R s = H ( s) = R = R
T (s) =
1
1
1
V1 ( s )
+R
+ Rs
+S
Rs
R
R2
1 t R2
h(t ) =
e
u (t )
R2
1
K
K2
1
1
H ( s)
R2
=
= 1+
=
G ( s) =
1
1 s
1 s
s
s+
s s +
s+
2
2
R2
R
R
1
1
2
2
K1 = R = 1
ECE301 Homework #7
1136. (solution)
Given g (t ) = ( e 60t sin(80t ) ) u (t ) and x(t ) = 20 cos(100t ) then
G (s) =
80
( s + 60)2 + 802
T ( s) = H ( s) = s G ( s) =
80 s
( s + 60)2 + 802
yss (t ) = xA T ( j ) cos(t + + )
x(t ) = 20 cos(100t ) x A = 20,
ECE301 Homework #6
11.6 (solution)
Using series and parallel equivalence
Ls ( R + Ls ) L2 s 2 + 3RLs + R 2
=
Z in = R + Ls / /( R + Ls ) = R +
Ls + R + Ls
2 Ls + R
Using twopath current division
1
I1 ( s )
R + Ls = I1 ( s ) = LsI1 ( s ) = Ls I1 ( s )
I
2002 is the 200th birthday of Jeremiah Wide, the first European settler in the area and the
man for whom Wideplace was named. The city council wants to mark the occasion by
constructing a 400 ft. tall statue of Wide in Creekside Park near downtown, but no
The cucumber slicer in your pickle factory cost $150,000 when it was purchased in early
1995. You estimated at that time that the slicer would be worth $40,000 at the end of its
sixyear expected life. What are the 1997 depreciation charge and the end of
2002 is the 200th birthday of Jeremiah Wide, the first European settler in the area and the
man for whom Wideplace was named. The city council wants to mark the occasion by
constructing a 400 ft. tall statue of Wide in Creekside Park near downtown, but no