Chap#03 Data Communications

Question 1

The device that converts the digital signal to a form that can pass through a transmission medium is:

Answer 1

Encoder

Question 2

The number of times a wave repeats itself during a specific time intervals its:

Answer 2

frequency

Question 3

Data can be in the form of:

Answer 3

➡Numbers
➡Images
➡Characters

Question 4

A combination of four binary digits is called:

Answer 4

Nibble

Question 5

The coding scheme that represents up to 65, 536 symbols:

Answer 5

Unicode

Question 6

Data communication requires:

Answer 6

➡Sender
➡Receiver
➡Medium

Question 7

The data transmission mode in which data flows in one direction only is:

Answer 7

SImplex

Question 8

The fastest mode of data transmission is:

Answer 8

Simplex

Question 9

Coaxial cables can transfer data at a maximum rate of:

Answer 9

100 Mbps

Question 10

Twisted pair cables can transfer data to a maximum distance of:

Answer 10

100 meters

Question 11

The cable that consists of tubes of glass through which data are transmitted as pulses of light is:

Answer 11

Fiber Optic

Question 12

The unguided media carry signals in the form o:

Answer 12

Electromagnetic Waves

Question 13

A system in which data can be received and sent simultaneous is called:

Answer 13

Full-duplex

Question 14

In data communication, the sender is also called:

Answer 14

Source

Question 15

Propagation of signals across a comunication medium is known as:

Answer 15

Transmission

Question 16

All of the following are true of the simplex mode except:

Answer 16

It is the most commonly used communication mode

Question 17

The exact format of the frame in case of synchronous transmission depends on whether the transmission scheme is read more:

Answer 17

Either character-oriented or bit-oriented

Question 18

A digital channel implies that the channel:

Answer 18

s carrying digital data

Question 19

The unguided media consists o:

Answer 19

➡Microwaves
➡Infrared waves

Question 20

A modem:

Answer 20

➡converts analog signals into digital signals
➡converts digital signals into analog signals

Question 21

The maximum dta rate that a medium of 10KHz and signal to noise ratio of 30dB is roughly:

Answer 21

30Kbps

Question 22

External modems:

Answer 22

➡are expensive
➡have more operational features
➡offer high transmission speed

Question 23

Which of the following medium does not use metallic conductor for transmission?

Answer 23

Optical fiber

Question 24

The maximum rate at which a modem can transmit data s around _____ bps.

Answer 24

14,400