Cnt 3004

Front 1

______ is the process of converting digital data to a digital signal

Back 1

Line coding

Front 2

PCM is an example of _____ conversion

Back 2

Analog-to-digital

Front 3

The Nyquist theorem specifies the minimum sampling rate to be

Back 3

twice the highest frequency of a signal

Front 4

The first step in PCM is _______

Back 4

sampling

Front 5

Which of the following quantization level results in a more faithful reproduction of the signal?

Back 5

32

Front 6

If the frequency spectrum of a signal has a bandwidth of 300 Hz with the highest frequency at 600 Hz, what should be the sampling rate, according to the Nyquist theorem?

Back 6

1200 samples/s

Front 7

In _________ transmission, we send bits one after another without start or stop bits or gaps. It is the responsibility of the receiver to group the bits.

Back 7

synchronous

Front 8

The ________ rate defines the number of data elements sent in 1s; the ______ rate is the number of signal elements sent in 1s.

Back 8

data;signal

Front 9

The minimum bandwidth of Manchester and differential Manchester is ____ that of NRZ.

Back 9

twice

Front 10

In Manchester and differential Manchester encoding, the transition at the middle of the bit is used for __________.

Back 10

synchronization

Front 11

In _______encoding, we use three levels: positive, zero, and negative.

Back 11

bipolar

Front 12

________ is normally referred to as mB/nB coding; it replaces each m-bit group with an n-bit group.

Back 12

block coding

Front 13

________ provides synchronization without increasing the number of bits.

Back 13

Scrambling

Front 14

_______ encoding has a transition at the middle of each bit.

Back 14

RZ, Manchester, Differential Manchester

Front 15

_______ provides redundancy to ensure synchronization and inherent error detection.

Back 15

block coding

Front 16

Block coding can help in _______ at the receiver.

Back 16

Synchronization and Error detection

Front 17

In _______ transmission, a start bit and a stop bit frame a character byte.

Back 17

asynchronous serial

Front 18

In _______ transmission, bits are transmitted simultaneously, each across its own wire.

Back 18

Parallel

Front 19

In asynchronous transmission, the gap time between bytes is _______.

Back 19

variable

Front 20

______ substitutes eight consecutive zeros with 000VB0VB.

Back 20

B8ZS

Front 21

Which encoding method uses alternating positive and negative values for 1s?

Back 21

AMI

Front 22

In _______ transmission, bits are transmitted over a single wire, one at a time.

Back 22

synchronous serial and asynchronous serial

Front 23

Which of the following encoding methods does not provide for synchronization?

Back 23

NRZ-L

Front 24

_________ media transport electromagnetic waves without the use of a physical conductor.

Back 24

Unguided

Front 25

________ are used for short-range communications such as those between a PC and a peripheral device.

Back 25

Infrared waves

Front 26

_____ cable can carry signals of higher frequency ranges than _____ cable.

Back 26

Coaxial; twisted-pair

Front 27

A parabolic dish antenna is a(n) _______ antenna.

Back 27

unidirectional

Front 28

In a fiber-optic cable, the signal is propagated along the inner core by _______.

Back 28

reflection

Front 29

Radio waves are _________.

Back 29

omnidirectional

Front 30

Signals with a frequency above 30 MHz use _______propagation.

Back 30

line-of-sight

Front 31

Transmission media lie below the _______ layer.

Back 31

physical

Front 32

What is the major factor that makes coaxial cable less susceptible to noise than twisted-pair cable?

Back 32

outer conductor

Front 33

What is the time between samples for a voice channel using PCM? Give the answer in microseconds.
Hint: Use the Nyquist sampling theorem on a 4 KHz voice channel

Back 33

125