Download 1. What is the voltage across the 20Ω resistor? a. 0 V b. 2 V c. 3 V d

1. What is the voltage across the 20Ω resistor?
a.
b.
c.
d.
e.
0V
2V
3V
4V
6V
2. What is the resistance R which would make VB = 3 V?
a. 1 kΩ
b. 2 kΩ
c. 3 kΩ
d. 4 kΩ
e. 6 kΩ
3. What is the value of the current-limiting resistor if the LED current is
20 mA, and the LED’s VON is 2 V?
a.
b.
c.
d.
e.
150 Ω
100 Ω
75 Ω
50 Ω
25 Ω
Page 1 of 22
4. What is I in the circuit below?
a.
b.
c.
d.
e.
0.06 A
0.10 A
0.15 A
0.20 A
0.30 A
5. Apply KCL to find I in the circuit below.
a.
b.
c.
d.
e.
I = 5 mA
I = 10 mA
I = 15 mA
I = 20 mA
I = 25 mA
6. Given that VB = 5 V, apply KCL at Node B, to calculate I, current into the
base of the transistor.
a.
b.
c.
d.
e.
I = 0.7 mA
I = 0.6 mA
I = 0.5 mA
I = 0.4 mA
I = 0.2 mA
7. What is the value of the current ?
a.
b.
c.
d.
e.
1 mA
2 mA
3 mA
5 mA
10 mA
Page 2 of 22
8. What is the value of the current ? HINT: Node voltage could be used.
a.
b.
c.
d.
e.
1 mA
2 mA
3 mA
5 mA
10 mA
9. What is the value of the current ? HINT: Node voltage should be used.
a.
b.
c.
d.
e.
1 mA
2 mA
3 mA
5 mA
10 mA
10.What is the value of the current ? Assume a large signal diode model with
= 0.7 .
a.
b.
c.
d.
e.
1.2 mA
4.3 mA
6.2 mA
7.4 mA
9.3 mA
Page 3 of 22
11.What is the average power dissipated by the 4 kΩ resistor?
a.
b.
c.
d.
e.
0 mW
1 mW
2 mW
3 mW
4 mW
12.Four of the seven identical resistive bulbs are labeled A, B, C, and D in the
circuit below. They are powered by an ideal voltage source. Given that
brightness is proportional to the current flowing through each bulb, which
labeled bulb is the brightest?
a. A
b. B
c. C
d. D
e. Not enough information to tell.
13. If the open circuit voltage of a circuit containing a source and some resistors
is measured at 8 V, while the current through the short circuit across the
circuit is 400 mA, what would be the current through a 60 Ω resistor
placed across the terminals?
a.
b.
c.
d.
e.
100 mA
133 mA
200 mA
400 mA
800 mA
Page 4 of 22
14.Find the Norton equivalent of the circuit below.
a.
b.
c.
d.
e.
IN = 0.3 A, RN = 10 Ω
IN = 1.5 A, RN = 10 Ω
IN = 0.3 A, RN = 8 Ω
IN = 1.5 A, RN = 1.6 Ω
IN = 0.3 A, RN = 1.6 Ω
15.Consider the two signals shown in these two graphs, where the peak voltage
_ is the same but the period of the bottom function is half the period of
the top function. For the top function, the RMS voltage is
10 V
(RMS).
What is the RMS voltage for the lower graph?
a.
b.
c.
d.
e.
100 20 10 5 √10 Page 5 of 22
16. Given the input voltage varying according to
1.5 + sin 20#
in which modes does the BJT operate?
Assume that $ = 100, %&,() = 0.7 and *&,+,- = 0.2 .
,
a. Active only
b. Saturation only
c. Cutoff (Off) and Active only
d. Active and Saturation only
e. Cutoff (Off), Active and Saturation
17.Which values of
%
and
*
lead to
a.
%
≥ 2.3 2Ω,
*
= 58 Ω
b.
%
≤ 2.3 2Ω,
*
= 58 Ω
c.
%
≥ 2.8 2Ω,
*
= 53 Ω
d.
%
≤ 2.8 2Ω,
*
= 53 Ω
e.
%
= 2.8 2Ω,
*
= 28 Ω
*
=
*,+,-
= 100
when
%
=3 ?
Page 6 of 22
18. Controlling the duty cycle of a square waveform is known as
a.
b.
c.
d.
e.
Pulse propagation
Pulse multiplication
Pulse-width dislocation
Pulse-width modulation
Pulse-stream modulation
19.Consider that 8 minutes and 20 seconds of music is recorded at a sampling
rate of 100 kHz and quantized with 16 bits/sample. The resulting file is then
compressed to the size of 5 MB. What is the compression ratio? (Assume
that 1 MB = 1000 kilobytes)
a.
b.
c.
d.
e.
5
8
10
16
20
20.Which signal waveform might have the spectrum shown below?
a.
b.
c.
d.
e.
3 + cos 2 + sin 4 )
3 + cos 4 + sin 8
3 + cos 2# + sin 4#
3 + cos 4# + sin 8#
3 + cos 2#200 + sin 2#400
Page 7 of 22
21.What is the maximum possible quantization error (in absolute value) if the
voltage signal 9
2 sin 8#
is digitized using a 1-bit quantizer with
output levels at 0 V and 1 V?
a. 0 V
b. 0.5 V
c. 1 V
d. 2 V
e. 4 V
22. Consider a mouse that can sing with frequencies up to 50 kHz.
The Nyquist sampling rate for this signal is
a. 25000 Samples/sec
b. 50000 Samples/sec
c. 100000 Samples/sec
d. 200000 Samples/sec
e. 400000 Samples/sec
23. How many bits does it take (per sample) to quantize to 64 levels?
a. 4 bits/Sample
b. 5 bits/Sample
c. 6 bits/Sample
d. 7 bits/Sample
e. 8 bits/Sample
Page 8 of 22
24.What ZIP code might this erroneous (containing an error) POSTNET code
likely represent?
a.
b.
c.
d.
e.
06630
06650
80027
90023
90027
25.Which code word below contains an error if a single parity bit was added to
each 3-bit message word?
The received sequence is: 1101 0100 1010 1110 0001
a. 1101
b. 0100
c. 1010
d. 1110
e. 0001
26.Each of four 3-bit words are encoded with an even parity bit on the right
(LSB), then protected further with an odd-parity word on the right of the
sequence. If the received message is
1101 1001 0110 0011 0110,
↑ odd ; paritywordcheckoncolumns
then the error-free message is likely given by
a. 110 100 011 001
Page 9 of 22
b. 010 100 011 001
c. 100 100 011 001
d. 111 100 011 001
e. 110 000 011 001
27. Each day, Rosencrantz flips two coins and gives Guildenstern the ones that
come up tails. What is the entropy of the number of coins Guildenstern
receives on a given day? HINT: G ∑I ⋅ log L MI ⋅ N
The table below can be used to calculate frequencies for each possibility
Flip result
HH
HT
TH
TT
Frequency
1/4
1/4
1/4
1/4
Coins received
0
1
1
2
a.
b.
c.
d.
1 bit
1.5 bits
2 bits
2.5 bits
e. log L 3 bits
Page 10 of 22
28. The following birds are observed at the bird feeder with the frequencies
given below. If a Huffman code is created to encode the visitors, which one
should be represented by the branch marked with the question mark?
Pigeons 50%
a.
b.
c.
d.
e.
Sparrows 25%
Crows 14%
Robins 11%
Robins
Crows
Sparrows
Pigeons
There is not enough information to tell.
29.In the circuit (below and right), the brightly-illuminated reverse-biased
photodiode operates in which quadrant of the IV characteristic curve (shown
at the bottom of the page)? Assume that the reverse bias current is less than
100 O and the turn on voltage is less than 1 V.
a. Quadrant A delivering (sourcing) power.
b. Quadrant B delivering (sourcing) power.
c. Quadrant C delivering (sourcing) power.
d. Quadrant A absorbing (dissipating) power.
e. Quadrant B absorbing (dissipating) power.
Page 11 of 22
30.What is the best graphical representation of the voltage across the resistor in
the circuit below, if the input voltage (in Volts) is given by 9P)
20sin 120# ? Hint: a diode turn on voltage of 0.7 V can be assumed,
which is much smaller than 20 V.
9(
9P)
20
a.
~
+
v0
─
t
9(
20
b.
t
9(
t
c.
-20
9(
t
d.
-20
9(
e.
t
Page 12 of 22
31.What is the current, I, supplied by the voltage source, if VON = 0.7 V?
a.
b.
c.
d.
e.
0 mA
60 mA
130 mA
190 mA
260 mA
2V
+
─
I
10 Ω
10 Ω
32. What happens to the output voltage if the second reverse-biased photodiode
(illuminated with the same brightness as the first) is connected in parallel with a single
photodiode in the original circuit (by closing the switch)?
a. Vout will remain the same
b. Vout will go down by a factor of two
+
c. Vout will go up by a factor of two 3 V
─
+
d. Vout will go to 0 V
Vout
100 Ω
e. Vout will go to 3 V
─
33.What is V0 if VB = 2.8 V, RB = 700 Ω, and RC = 6 Ω?
a.
b.
c.
d.
e.
1.8 V
2.4 V
3.6 V
4.2 V
6V
34. What is IC if VB = 5.6 V, RB = 700 Ω, and RC = 10 Ω?
a. 800 mA
b. 700 mA
c. 580 mA
d. 490 mA
e. 210 mA
Page 13 of 22
35. Consider the input voltage in the form %
Q* +
* cos 2000# . If RB = 1000 Ω,
and RC = 200 Ω, what is the maximum possible amplitude of the AC portion, * , that
keeps the transistor in the active regime at all times. Hint: consider the input/output
voltage relationship and note that Q* can be chosen to maximize * .
a. 145 mV
b. 290 mV
c. 555 mV
d. 845 mV
e. 990 mV
36. Approximately how many “raw” format 4-megapixel (4×106 pixels/image) images can be
stored on an 8 GB (~8×109 Bytes) SD card, if 48 bits (3×16, 16 per color) are stored for
every pixel? Hint: 1 Byte = 8 bits
a. 40
b. 120
c. 330
d. 2,000
e. 16,000
37. How many bits per sample are needed to digitize a voltage waveform if its voltage range
is from -1 V to 1 V and the levels should be less than 10 mV apart?
a. 6
b. 8
c. 12
d. 32
e. 128
38. What is the minimum sampling rate required to preserve (digitize and correctly
reproduce) all signal frequencies ranging from 60 Hz to 4 kHz?
a. 60 Hz
b. 120 Hz
c. 2 kHz
d. 4 kHz
e. 8 kHz
Page 14 of 22
39. Which of the following mouse squeak frequencies aliases to 2 kHz if the A/D converter’s
sampling rate is set to 20 kHz?
a. 4 kHz
b. 8 kHz
c. 12 kHz
d. 18 kHz
e. 28 kHz
40. An error detection scheme uses one bit of each 8-bit word as a parity check. If the
following five words were received (a-e), which one contains the only bit error in the
transmission?
11000101 01101111 10110100 11101000 11010101
a.
b.
c.
d.
e.
11000101
01101111
10110100
11101000
11010101
41. A 12-bit message is broken up into four words and a parity bit is added to each one.
Another parity word is added to the message to enable error correction. In total, how
many redundant bits (bits that are not in the original 12-bit message) are added to the
transmission?
a. 4
b. 5
c. 6
d. 7
e. 8
42. Each of four 4-bit words are encoded with an even parity bit on the right (LSB), then
protected further with an odd-parity word on the right of the sequence:
11011 10010 01101 00101 11100
The recovered message is then given by:
a.
b.
c.
d.
e.
1101 1001 0110 0010
1101 1011 0110 0010
1101 1001 1110 0010
1101 1001 0111 0010
1101 1001 0110 0011
Page 15 of 22
43. What is the size of the mp3 file produced from a 30 MB uncompressed audio file if the
compression ratio is 20?
a. 1.5 MB
b. 6 MB
c. 10 MB
d. 20 MB
e. 24 MB
44. The following birds are observed at the bird feeder with the frequencies given below. If
a Huffman code is created to encode the visitors, which of the following is a correct
code for robins? Pigeons 47%
Sparrows 25% Robins 15% Crows 10% Jays 3%
a. 0
b. 10
c. 111
d. 1101
e. 1100
45. What is the approximate weather report entropy on an island where it is sunny 80% of
the days, cloudy – 10%, rainy – 8%, and stormy – 2%. Hint: you can either use the
property of logarithms to calculate, or come up with an efficient encoding of your
choice.
a. between 1 and 1.5 bits
b. between 1.5 and 2 bits
c. between 2 and 2.5 bits
d. between 2.5 and 3 bits
e. between 3 and 4 bits
Page 16 of 22
46. Apply KVL to find the values of V1 and V2 in the diagram below.
+4Va. V1 = 7 V, V2 = 19 V
b. V1 = 7 V, V2 = 5 V
+ V1 c. V1 = 5 V, V2 = 7 V
d. V1 = 1 V, V2 = 11 V
+
+
e. V1 = 1 V, V2 = 13 V
V2
-
12 V
-
I1
47. Apply KCL to find the values of I1 and I2 in the diagram below.
a. I1 = 0.1 A, I2 = 0.3 A
b. I1 = 0.1 A, I2 = 0.4 A
c. I1 = 0.3 A, I2 = 0.4 A
d. I1 = 0.9 A, I2 = 0.4 A
0.5 A
e. I1 = 0.9 A, I2 = 0.7 A
48. What is the value of Vout in the circuit below?
a. Vout = 1.5 V
b. Vout = 2 V
c. Vout = 3 V
d. Vout = 4.5 V
e. Vout = 6 V
49. What is the value of I in the circuit below?
a. 4 mA
b. 6 mA
c. 9 mA
d. 11 mA
22 mA
e. 18 mA
+3V-
0.2 A
I2
0.2 A
1Ω
6V
+
─
+
Vout
-
3Ω
I
2 kΩ
3 kΩ
6 kΩ
Page 17 of 22
50. What happens to the brightness of the two light bulbs below when the switch is closed,
connecting the third light bulb to the circuit? You can assume that light bulbs are like
resistors, and that a bulb’s brightness is proportional to the current through it.
a. Both bulbs get brighter
b. Both bulbs get dimmer
c. Bulb 1 gets brighter, bulb 2 gets dimmer
1
d. Bulb 1 gets dimmer, bulb 2 gets brighter
+
e. Both bulbs stay the same
2
─
51. Which is the brightest light bulb in the circuit below? You can assume that all light bulbs
are like equivalent resistors, and that a bulb’s brightness is proportional to the current
through it.
a. Bulb 1
b. Bulb 2
1
2
c. Bulb 3
d. Bulb 4
+
e. Bulb 5
3
─
5
4
52. What are the resistances of the resistor network below, taken at different nodes?
4 kΩ
4 kΩ
a. RAB = 3 kΩ, RBC = 3 kΩ A
b. RAB = 3 kΩ, RBC = 8 kΩ
c. RAB = 4 kΩ, RBC = 3 kΩ
d. RAB = 4 kΩ, RBC = 8 kΩ 4 kΩ
4 kΩ
4 kΩ
4 kΩ
e. RAB = 8 kΩ, RBC = 4 kΩ
4 kΩ
B
4 kΩ
Page 18 of 22
C
B
53. What R is needed to make RAB = 4 kΩ?
a. 1 kΩ
b. 2 kΩ
c. 3 kΩ
d. 4 kΩ
e. 5 kΩ
A
6 kΩ
R
5 kΩ
5 kΩ
B
54. What is the node voltage, VA, in the circuit below?
a. 2 V
b. 2.2 V
c. 2.5 V
+
d. 2.8 V
3V
─
e. 3.5 V
VA
100 Ω
100 Ω
55. What is the power dissipated (absorbed) by the current source?
a. 6 mW
b. 10 mW
c. 16 mW
100 Ω
d. 30 mW
+
3V
e. 42 mW
─
+
─
400 Ω
1.5 V
100 Ω
400 Ω
10 mA
Page 19 of 22
56. What is the node voltage, VA, in the circuit below?
a. 1 V
100 Ω
b. 1.2 V
VA
c. 1.5 V
d. 1.8 V
+
3V
100 Ω
e. 2.4 V
─
100 Ω
100 Ω
0.03 A
57. Consider a circuit, C, with two terminals, as shown connected to three loads below. If its
open-circuit voltage is 6 V, short circuit current is 3 A, what is the power dissipated
(absorbed) by a 4 Ω load connected to the circuit?
+
6V
─
C
a.
b.
c.
d.
e.
C
C
3A
4Ω
36 W
18 W
6W
4W
2W
58. What is the Thevenin equivalent of the circuit below?
150 Ω
3V
+
─
RT
300 Ω
a.
b.
c.
d.
e.
VT
+
─
VT = 3 V, RT = 300 Ω
VT = 3 V, RT = 150 Ω
VT = 3 V, RT = 100 Ω
VT = 2 V, RT = 300 Ω
VT = 2 V, RT = 100 Ω
Page 20 of 22
59. What does an IV curve of a resistor look like?
a. Horizontal line
b. Vertical line
c. Line through the origin
d. Line with two distinct intercepts (I and V)
e. L-shaped curve
60. What is a good estimate of average power delivered to a 100 Ω light bulb, if the AC
voltage across it is given by the following equation?
9
140RS (120#
a. 70 W
b. 100 W
c. 140 W
d. 200 W
e. 280 W
61. What is the average (DC) value of the periodic waveform, with two periods shown
below?
T(
a. 0 V
4
b. 0.5 V
c. 1 V
d. 1.5 V
t
U
LU Y
XU 2Y
WU
e. 2 V
-2
V
V
V
V
Page 21 of 22
Fact Sheet:
G
∑ZP log L
log L \
log \ /log 2
log L \^
log L
(a ,b
1
1
1
=
∑ZP logT[
ZP logT[ 2
ZP
log L \ + log L ^
1
= ; log L \ ; log L 2` = 2
\
c(d
,
= (ac(d
b
c(d
POSTNET digit assignments
Digit
1
2
3
4
5
Code
00011
00101
00110
01001
01010
Digit
6
7
8
9
0
Code
01100
10001
10010
10100
11000
Page 22 of 22