Data Communication solved paper

CS601- Data Communication Solved paper

Time: 60 min

Marks: 40

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Question No: 1 ( Marks: 1 ) - Please choose one

The information to be communicated in a data communications system is the

_ Medium

_ Protocol

_ Message p_5

_ Transmission

Question No: 2 ( Marks: 1 ) - Please choose one

Which is not an element of protocol

_ semantics

_ timing

_ communication service module  p_17-18

Question No: 3 ( Marks: 1 ) - Please choose one

Line configuration refers to the way two or more devices attach to a ______.

_ Link  p_24

_ Circuit

_ Route

_ Node

Question No: 4 ( Marks: 1 ) - Please choose one

_________requires the maximum number of I/O ports.

_ Bus

_ Star

_ Mesh  p_28-29

_ Ring

Question No: 5 ( Marks: 1 ) - Please choose one

Which topology requires a central controller or hub?

_ Mesh

_ Star p_29

_ Bus

_ Ring

Question No: 6 ( Marks: 1 ) - Please choose one

Layers 5, 6 and 7 also called as network support layers.

_ True

_ False p_42

Question No: 7 ( Marks: 1 ) - Please choose one

Internet with small “i” specifies the world wide Network the actual internet.

_ True

_ False p_39

Question No: 8 ( Marks: 1 ) - Please choose one

Data link layer deals with mechanical and electrical specifications of transmission

medium and interface

_ True

_ False p_44

Question No: 9 ( Marks: 1 ) - Please choose one

Data synchronization is a function related with ___________

_ session layer p_52

_ presentation layer

_ transport

Question No: 10 ( Marks: 1 ) - Please choose one

OSI model was developed prior to TCP/IP model.

_ True

_ False p_56

Question No: 11 ( Marks: 1 ) - Please choose one

Fourier transform tells us that any digital signal can be decomposed into infinite

number of periodic signals

_ True p_61

_ False

Question No: 12 ( Marks: 1 ) - Please choose one

A signal that repeats a pattern over a regular interval of time is called_______.

_ periodic signal p_60

_ analog signal

_ composite signal

Question No: 13 ( Marks: 1 ) - Please choose one

Frequency band in which 99% of the total power resides is called_______

_ power bandwidth p_70

_ half power bandwidth

_ 3dB bandwidth

_ F.M.

Question No: 14 ( Marks: 1 ) - Please choose one

In differential Manchester we require two transition or signal changes to

represent binary_____

_ zero p_78

_ one

_ both zero and one

Question No: 15 ( Marks: 1 ) - Please choose one

In Alternate mark inversion the term mark comes from_________

_ telegraphy p_79

_ telephony

_ digital telephony

Question No: 16 ( Marks: 1 ) - Please choose one

A 56k modem can download at a rate of __________ Kbps and upload at a rate

of __________ Kbps.

_ 33.6: 33.6

_ 33.6: 56.6 p_122

_ 56.6: 33.6

_ 56.6: 56.6

Question No: 17 ( Marks: 1 ) - Please choose one

The bit rate always equals the baud rate in which type of signal?

_ FSK p_92

_ QAM

_ 4-PSK

_ PSK

Question No: 18 ( Marks: 1 ) - Please choose one

Asynchronous transmission is ___________

_ slow p_103

_ costly

_ non-effective

_ fast

Question No: 19 ( Marks: 1 ) - Please choose one

At the ______________layer, a DCE takes data generated by a DTE.

_ physical p_106

_ transport

_ data link

_ application

Question No: 20 ( Marks: 1 ) - Please choose one

_________ requires more bandwidth.

_ FSK

_ ASK

_ PSK p_94

_ QAM

Question No: 21 ( Marks: 2 )

Define Sampling Rate.

Solution: p_85

The accuracy of any digital production of an analog signal depends upon

the o. of samples taken

How many samples are sufficient?

<Nyquist theorem>

The sampling rate must be at least twice the highest frequency

Question No: 22 ( Marks: 2 )

Write down the types of digital to analog modulation.

Solution: p_88

Types of digital to analog modulation

ASK

FSK

PSK

QAM

Question No: 23 ( Marks: 3 )

What is periodic signal?

Solution: p_60

A signal is called Periodic if it completes a pattern within a measurable

time frame called a Period and then repeats that pattern over identical

subsequent Periods

The completion of one full pattern is called a CYCLE

Period: Time required (in Seconds) to complete one full cycle, represented

by ‘T’.

Question No: 24 ( Marks: 3 )

How bandwidth of a Modem is measured?

Solution: p_115

Question No: 25 ( Marks: 5 )

Briefly describe Rerturn to Zero (RZ) encoding scheme?

Solution: p_77

Question No: 26 ( Marks: 5 )

Compare Phase Modulation(PM) with Frequency Modulation(FM)?

Solution:

Lecture # 19, p_99

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