1. Which of the following forms of data assume continuous values on some interval?
a. digital data
b. digital signal
c. analog data
d. analog signal
2. Which of the following refers to a continuously varying electromagnetic wave that
may be transmitted over a variety of media, depending on the frequency?
a. digital data
b. analog signal
c. analog data
d. digital signal
3. Which of the following devices converts a series of binary voltage pulses into an
analog signal by modulating a carrier frequency?
a. modem
b. CODEC
c. digital transmitter
4. Which of the following devices is used to convert analog voice signals by
approximating the signal by a bit stream on one end and then reconstructing the
analog signal at the other end?
a. CODEC
b. digital transmitter
c. modem
5. Which of the following digital encoding techniques is based on the sampling theorem
that states that if a signal is sampled at regular intervals of time and at a rate higher
than twice the highest significant signal frequency, the samples contain all the
information of the original signal?
a. PCM
b. FDM
c. TDM
6. In which of the following forms of transmission is each character 5 to 8 bits in length,
where synchronization is maintained within each character?
a. isochronous
b. asynchronous
c. synchronous
7. Which of the following provides connectivity for DTE to the transmission system?
a. DACS
b. DCE
c. DDS
8. What are the two elements involved in the error control process?
a. error detection and acknowledgement
b. error detection and correction
c. error correction and isolation