Name:     ID: 
 
Email: 

ENGR3520HomeworkChapter2

Multiple Choice
Identify the choice that best completes the statement or answers the question.
 

 1. 
Most digital circuits represent binary values using ________.
a.
0 V and +5 V
c.
-5 V and +5 V
b.
-5 V and 0 V
d.
-12 V and +12 V
 

 2. 
LOW (or binary 0) in a digital system typically corresponds to ________.
a.
0 V
c.
+5 V
b.
-5 V
d.
-10 V
 

 3. 
HIGH (or binary 1) in a digital system typically corresponds to ________.
a.
0 V
c.
+5 V
b.
-5 V
d.
+10 V
 

 4. 
A change from HIGH to LOW voltage in a digital clock signal is known as
a.
falling edge.
c.
period.
b.
frequency.
d.
rising edge.
 

 5. 
The rising edge of a digital clock occurs when
a.
the signal changes from LOW to HIGH.
c.
the signal is HIGH.
b.
the signal changes from HIGH to LOW.
d.
the signal is a logic one.
 

 6. 
What is the frequency of a clock waveform whose period is 20 microseconds?
a.
50 kHz
c.
25 kHz
b.
2 MHz
d.
5 kHz
 

 7. 
What is the frequency of a clock waveform whose period is 5 milliseconds?
a.
200 Hz
c.
2 kHz
b.
500 Hz
d.
2.5 kHz
 

 8. 
What is the period of a clock waveform whose frequency is 4 MHz?
a.
250 ms
c.
.25 ms
b.
40 ìs
d.
.25 ìs
 

 9. 
What is the period of a clock waveform whose frequency is 150 kHz?
a.
3.33 ìs
c.
66 ms
b.
6.66 ìs
d.
160 ìs
 

 10. 
Digital signals transmitted on a single conductor (and a ground) must be transmitted in
a.
serial.
c.
parallel.
b.
analog.
d.
slow speed.
 

 11. 
Serial format means digital signals are
a.
sent in binary coded decimal.
b.
sent over one conductor sequentially.
c.
sent over many conductors simultaneously.
d.
sent in groups of eight signals.
 

 12. 
Which of the following could only be a serial data operation?
a.
computer communication to a device on the IEEE-488 bus
b.
sending data from a computer to a printer
c.
receiving an e-mail message across the Internet
d.
the internal data movement in a microprocessor
 

 13. 
Parallel format means that
a.
both binary and hexadecimal can be used.
b.
each digital signal has its own conductor.
c.
no clock is needed.
d.
several digital signals are sent on each conductor.
 

 14. 
Which format requires fewer conductors?
a.
serial
c.
Both are the same.
b.
parallel
d.
cannot tell
 

 15. 
Which format can send digital information faster?
a.
serial
c.
Both are the same.
b.
parallel
d.
cannot tell
 

 16. 
A relay whose contacts close when energized is
a.
a NO relay.
c.
normally closed.
b.
an NC relay.
d.
defective.
 

 17. 
Which of the following is an advantage of a mechanical relay over semiconductor switches?
a.
low current needed to energize
b.
high speed
c.
total isolation between source and output
d.
all of the above
 

 18. 
A relay whose contacts are touching at rest is called
a.
a NO relay.
c.
a normally open relay.
b.
a normally closed relay.
d.
an energized relay.
 

 19. 
When current is applied to the coil of an NC relay,
a.
it closes.
c.
it opens.
b.
its contacts touch.
d.
it opens and its contacts touch.
 

 20. 
When a NO relay is energized, its contacts are
a.
opened.
c.
at rest.
b.
closed.
d.
closed and at rest.
 

 21. 
A diode conducts when it is
a.
forward biased.
c.
energized.
b.
positive.
d.
reverse biased.
 

 22. 
When a diode is reverse biased, it
a.
malfunctions.
c.
passes current.
b.
blocks current.
d.
is energized.
 

 23. 
A diode is reverse biased when its anode is
a.
more negative than the cathode.
c.
more positive than the cathode.
b.
at 0 V.
d.
a positive voltage.
 

 24. 
A transistor can function as a
a.
relay.
c.
power supply.
b.
light.
d.
switch.
 

 25. 
A solid state device which can function as a switch is
a.
a resistor.
c.
a transistor.
b.
a diode.
d.
a diode and a transistor.
 

 26. 
An NPN transistor will short from emitter to collector when
a.
the collector is more positive than the emitter.
b.
the base is more positive than the emitter.
c.
the base is more negative than the emitter.
d.
the emitter is more positive than the collector.
 

 27. 
When the base is more positive than the emitter of an NPN transistor, it is
a.
ON.
c.
open.
b.
OFF.
d.
cannot tell.
 

 28. 
When the base is more negative than the emitter of a PNP transistor, it is
a.
open.
c.
ON.
b.
OFF.
d.
cannot tell.
 

 29. 
Which statement describes a TTL inverter?
a.
When the input is 0 V, the output is 0 V.
b.
When the input is +5 V, the output is OFF.
c.
When the input is +5 V, the output is +5 V.
d.
When the input is 0 V, the output is +5 V.
 

 30. 
The most common family of ICs using NPN transistors is called
a.
DTL.
c.
TTL.
b.
RTL.
d.
CMOS.
 

 31. 
A TTL inverter actually consists of
a.
a diode and a transistor.
c.
two transistors.
b.
one transistor and several resistors.
d.
several transistors and resistors.
 

 32. 
A figure that shows a digital signal's voltage versus time is called a(n)
a.
digital pulse.
c.
timing diagram.
b.
schematic.
d.
oscilloscope.
 

 33. 
An instrument that shows a digital signal's voltage versus time is called a(n)
a.
timing diagram.
c.
digital pulse.
b.
oscilloscope.
d.
schematic.
 

 34. 
A waveform that is repetitive at a specific time interval is called
a.
timing.
c.
periodic.
b.
digital.
d.
frequency.
 

 35. 
Digital transmissions at one bit for each clock period is
a.
parallel.
c.
LSB.
b.
serial.
d.
MSB.
 

 36. 
How long will it take to transmit four 8-bit binary strings in serial if the clock frequency is 10 MHz?
a.
0.25 ìs
c.
4.0 ìs
b.
25 ìs
d.
0.4 ìs
 

 37. 
Which of the following is not an example of a switch in electrical circuits?
a.
diode
c.
transistor
b.
fuse
d.
electromechanical relay
 

 38. 
A forward-biased silicon diode has approximately ________ across its terminals.
a.
1.2 V
c.
0.0 V
b.
5.0 V
d.
0.7 V
 

 39. 
A low power consumption IC is the
a.
TTL.
c.
CMOS.
b.
RPG.
d.
PTT.
 

 40. 
Surface-mounted devices are ________ DIP styles.
a.
not capable of high frequencies like
c.
easier to mount than
b.
larger than
d.
smaller than
 

 41. 
Which of the following are not terms associated with surface mount devices?
a.
PLCC
c.
SO
b.
DIP
d.
SMD
 

 42. 
How long will it take to transmit four 8-bit binary strings in serial if the clock frequency is 1 MHz?
a.
40 ìs
c.
4.0 ìs
b.
4.0 ms
d.
0.4 ìs
 

 43. 
How long will it take to transmit four 8-bit binary strings in parallel if the clock frequency is 10 MHz?
a.
0.1 ìs
c.
1.0 ìs
b.
4.0 ìs
d.
0.4 ìs
 



 
         Start Over