1. An example of digital, rather than analog, communication is?
a) DDD
b) DDS
c) WATS
d) DDT

2. The channel in the data communication model can be?
a) postal mail services
b) telephone lines
c) radio lines
d) non of the above

3. A data terminal serves as an?
a) Effector
b) sensor
c) both a and b
d) neither a nor b

4. Which of the following transmission systems provide the highest data rate to in individual device?
a) computer bus
b) telephone lines
c) voice and mode
d) lease lines

5. A remote batch-processing operation in which data is only input to a central computer would require?
a) telegraph line
b) simplex lines
c) mixed bad channel
d) all of above

6. An example of a medium speed, switched communications service is?
a) series 1000
b) data phone 50
c) DDD(Direct distance dialing)
d) All of the above

7. In communication satellite, multiple repeaters are known as?
a) detector
b) modulator
c) stations
d) transponders

8. Which data communication method is used to transmit the data over a serial communication link?
a) simplex
b) half-duplex
c) full-duplex
d) b and c

9. A communications device that combines transmissions from several I/O devices into one line is a?
a) concentrator
b) modifier
c) multiplexer
d) full-duplex line

10. In a synchronous modem, the digital-to-analog converter transmits signal to the?
a) equalizer
b) modulator
c) demodulator
d) terminal