Exam May 2017, questions PDF

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Examination Question Paper: May 2018 Module code: CS5001 Module title: Networks and Operating Systems Module leader: Dr. Peiyuan Pan Date: 21 May 2018 Start time: 10:00 Duration: 2 hours Exam type: Unseen / Closed Materials supplied: Standard Examination Materials Materials permitted: Writing instru...

Description

Examination Question Paper:

May 2018

Module code:

CS5001

Module title:

Networks and Operating Systems

Module leader:

Dr. Peiyuan Pan

Date:

21 May 2018

Start time:

10:00

Duration:

2 hours

Exam type:

Unseen / Closed

Materials supplied:

Standard Examination Materials

Materials permitted:

Writing instrument only. No calculators are allowed during the test.

Warning:

Candidates are warned that possession of unauthorised materials in an examination/test is a serious assessment offence.

Instructions to candidates:

* Candidates should answer Section A, and plus ANY THREE out of the FOUR Questions in Section B. * You are NOT allowed to take the question paper out of the examination/test room. Question papers will be collected by the invigilator at the end of the exam/test.

DO NOT TURN PAGE OVER UNTIL INSTRUCTED! © London Metropolitan University

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Section A (40 marks in total, 2 marks each) For each question in this section, there are four possible answers, indicated by i), ii), iii), or iv). You need to give your answer in your answer book in the format like 22) i), which means you have chosen option i) for question 22 as the correct answer. For certain questions, more than one option may appear to be correct. In such cases, choose the best option. 1)

Communication channel is shared by all the machines on the network in i) Unicast network ii) Multicast network iii) Broadcast network iv) None of the above

2)

HUB is a _____ device and Switch is a _________ device i) Unicast, Multicast ii) Broadcast, Unicast iii) Multicast, Unicast iv) None of above

3)

Which of the following is the best for Ethernet to work on? i) Coaxial cable ii) Twisted pair cable iii) Optical fiber iv) None of the above

4)

Network congestion occurs i) When a system has faults ii) When power is down iii) When connection between two processing nodes terminates iv) In case of traffic overloading

5)

Which one is NOT a key parameter of transmission waves: i) Amplitude ii) Wave length iii) Frequency iv) i) & iii)

6)

What is the access point (AP) in wireless network? i) Device that allows wireless devices to connect to a wired network ii) Wireless devices themselves iii) Both i) and ii) are correct iv) None of the above

7)

Communication between a computer and a keyboard involves i) Automatic transmission ii) Simplex transmission iii) Half-duplex iv) Full-duplex

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8)

Which of the following has a signal communication channel that is shared by all the users on the network? i) Point-to-Point ii) Broadcast network iii) Protocol iv) Private Area Network

9)

Which of the following is the advantage when use fiber optics for data transmission? i) Higher bandwidth ii) Resistance to data theft iii) Low noise level iv) All of above

10)

A set of rules and guidelines for communicating data is called i) Physical layer ii) Bus topology iii) Protocols iv) Communication media

11)

Which one is correct for transmission signals? i) Signals are electromagnetic waveforms ii) Signals move close to the speed of light iii) i) and ii) iv) None of above

12)

Which memory allocation policy allocates the largest hole to the process? i) Best-fit ii) Worst-fit iii) First fit iv) None of the above

13)

The address of the next instruction to be executed by the current process is provided by the i) Control bus ii) Stack pointer iii) I/O interruptions iv) Program counter

14)

In which type of the following OS, response time is very crucial i) Networking operating system ii) Real time operating system iii) Batch operating system iv) UNIX operating system

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15)

An operating system is a program that i) Helps in check the spelling of your source code ii) Maintain the relationship in database iii) Manages the resources of the computer iv) None of the above

16)

Which of the following are the disadvantages of single-user systems? i) No support for multiprogramming or networking ii) Not cost effective iii) Program size must be less than memory size to execute iv) All of the above

17)

Which of the following variables is used by shell of UNIX to record the number of arguments supplied to a script? i) $# ii) $read iii) $output iv) $file

18)

Most operating systems provide a set of system calls, which invoke low level OS functions. Which of the following is a feature of system calls? i) The use of system calls is direct to the user ii) The use of system calls is not direct, hidden from the user iii) Systems calls are not hidden from the user iv) None of the above

19)

Which of the following is responsible for all file I/O initiation and termination? i) A specific I/O device ii) Process management iii) Device manager iv) Basic I/O interruptions

20)

User interface is the users’ gateway into the computer, enabling the required humancomputer interaction to take place. It ultimately requires i) software link to the hardware even if such link is buried beneath other layers of software ii) the user to decide how to link to hardware iii) i) and ii) iv) none of above

-----END

of Section A-----

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Section B ----- Answer ANY THREE Questions in this Section ----Question 1 (20 marks in total) a) Briefly describe what conducted media is, and what is radiated media? [8 marks] b) Briefly define bandwidth. What is the unit of measurement for bandwidth? An analogue communications channel CH is capable of transmitting signals in the range from 200 Hz to 4200 Hz. Calculate the bandwidth of the communications channel CH. [7 marks] c) Shannon’s equation to calculate the maximum amount of data that can be transmitted per second: S = B log2 (1 + (W/N)). S is Transmission Speed (Bits/second), B is bandwidth (Hertz), W is power of signal (Watts) and N is noise on the line (Watts). Assume W/N = 255 and B = 3000, what is the transmission speed? (Please note that 27 is 128.) [5 marks]

Question 2 (20 marks in total) a) CSMA/CD is used in local area networking using Ethernet technology. You are required to answer the following two questions: [10 marks]  Explain what CSMA/CD stands for (4 marks)  What algorithm is used by this protocol? (6 marks) b) In Token ring topology networking, all of the computers are connected in a loop and data is passed from one workstation to another. You are required to describe the working steps if a workstation wishes to transmit data. [10 marks]

Question 3 (20 marks in total) An interrupt is a signal which can cause the operating system to suspend its current activity and deal with the new situation. Please answer the following questions: a) What types of interrupt resources exist? [10 marks] b) The simplest view of processor action is that it consists of a simple fetch-execute cycle. If an interrupt mechanism is incorporated into the cycle, i.e., after each instruction terminates, the processor checks for the occurrence of an interrupt. Please describe how the process cycle will be affected in order to provide the service to the interrupt, and draw a diagram to illustrate [10 marks]

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Question 4 (20 marks in total) a) Memory management and device management are two essential managers in the operating systems. You are required to list TWO main responsibilities [10 marks, 5 marks each] b) The role of the Process Control Blocks (PCB) is central in process management. PCBs store many different items of data, which are needed for process management to work correctly and efficiently. You are required to list FOUR items of data the PCB should store. [10 marks, 2.5 marks each]

END OF THE PAPER

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