E238 Information Systems 12 TEE Data
Communications Questions Combo 1997-2000
Communications Questions Combo 1997-2000
Communications Questions Combo 1997-2000 |
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PART A Multiple Choice Items
Attempt all questions in this part. Each question is worth 1 mark. Each question has only one correct response. For each question select the response that is correct. Signify your answer by circling the label (a, b, c or d) of the correct response. If you change your answer, completely erase your original answer. Questions where two or more responses are selected will score no marks.
1997 PART A Multiple Choice Items
5. A family wished to connect their home computer to the Internet using a standard telephone line. Why does this family need a modem?
(a) Without a modem, the maximum data transfer rate is only 300 bits per second
(b) Modems have encryption algorithms built into their circuits to prevent unauthorised users from reading the transmissions.
(c) A modem is required to translate between the analogue signals transmitted through the standard telephone line and the computer’s digital signals.
(d) A modem performs the necessary translations between the Internet communication protocols and those protocols understood by the home computer.6. This table compares two types of network cabling. Which entries should be substituted for 1, 2, 3 and 4 to complete this table correctly?
UTP Optical fibre Bandwidth
Small Large Security
(1) (2) Cost per metre
Small Large Cost per Megabyte
Large Small Susceptibility to electromagnetic interference
(3) (4) Distance between repeaters
100 m 50 km (a) 1: Secure; 2: Not secure; 3. Susceptible; 4: Not susceptible
(b) 1: Secure; 2: Not secure; 3. Not susceptible; 4: Susceptible
(c) 1: Not secure; 2: Secure; 3. Not susceptible; 4: Susceptible
(d) 1: Not secure; 2: Secure; 3. Susceptible; 4: Not susceptible7. In the OSI-ISO network model, the data link layer describes
(a) the packaging of data and how error detection and correction are handled.
(b) the data transfer mechanism between network nodes.
(c) how different network nodes can communicate with each other.
(d) the electrical connections required.8. A software metric is
(a) a measurement of some software characteristic.
(b) the Australian decimal equivalent of an American software measurement.
(c) a methodology for software development.
(d) a programming language.END OF 1997 PART A
1998 PART A Multiple Choice Items
9. In the ISO-OSI network model, which layer is responsible for the access, transfer and management of files?
(a) The link layer.
(b) The presentation layer.
(c) The application layer.
(d) The session layer.10. The digital networks standard X.25 defines:
(a) a maximum CD-ROM rotation speed.
(b) error detection and correction techniques.
(c) a method of contention within local area networks.
(d) packet switching protocols used on public data networks.END OF 1998 PART A
1999 PART A Multiple Choice Items
5. A modem is designated by the term 56K. To what does the number 56 refer?
(a) Speed at which the modem can transfer data.
(b) Number of K type pins on the connecting cable.
(c) Maximum amount of data buffered by the modem.
(d) The digital standard supported by the modem.6. Which of the following statements about the microwave communications medium is incorrect?
(a) Microwave signals form the basis of all local area networks.
(b) Microwave transmissions are economical due to the low cost per bit.
(c) Microwave repeaters must be placed in line of sight.
(d) Microwaves have a large bandwidth—typically between 1 and 30 GHz.END OF 1999 PART A
2000 PART A Multiple Choice Items1. Which statement about ISDN is correct?
(a) Data may be transmitted in digital or analogue form over the communication line.
(b) Digital signals are modulated and demodulated much faster than with a modem.
(c) Data is transmitted more clearly but more slowly than with a modem.
(d) Data from computers, fax machines and telephones may all be transmitted on the same communication line.2. RS232 may be described as the standard:
(a) by which CD ROMs store data for different platforms.
(b) interface for peripherals using a serial connection.
(c) for encoding characters for digital transmission.
(d) for expansion boards for portable computers.END OF 2000 PART A
1997 PART B Short AnswersQuestion 24. (3 marks)
In attempting to describe the operation of a facsimile machine to a friend, a student described the facsimile machine as a “scanner, modem and printer—all stuck together”. Explain the operation of a facsimile by expanding on this simple description. (10 lines)
Question 25. (1 mark)
How does data terminal equipment differ from data communications equipment? (4 lines)
END OF 1997 PART B
1998 PART B Short Answers
16. How does an information system differ from a communication system? (3 lines) [2 marks]
24. With reference to electronic communication, what is “noise”? (2 lines) [1 mark]
25. Name two error detection techniques used in data communications. (2 lines) [1 mark]
26. Over the past decade there has been a gradual acceptance of international standards for data communication.
(a) Provide one reason why such standards are necessary. (2 lines) [1 mark](b) Name one data communications standard. (1 line) [1 mark]
27. The use of passwords is a common security measure on computer systems. This effectively limits access, but it is important that passwords are not discovered by anyone else. List three measures to reduce the chance of this happening. (5 lines) [2 marks]
END OF 1998 PART B
1999 PART B Short Answers
16. (a) What is encryption? (2 lines) (1 mark)
- (b) What is decryption? (2 lines) (1 mark)
17. In terms of data communications, what is one difference between a bridge and a router? (3 lines) (2 marks)
END OF 1999 PART B
2000 PART B Short Answers
16. One of the problems associated with transmission of data over some communications media is “attenuation”.
(a) What is attenuation? (2 lines) (1 mark)(b) What can be done to overcome this problem? (2 lines) (1 mark)
17. A secondary school student found an interesting web site in a popular teenage magazine. However, when the web site address was typed into a web browser at school, the site was not loaded into the browser. Suggest two reasons why this may have occurred. (4 lines) (2 marks)
18. (a) What do the acronyms LAN and WAN represent? (1 line each) (1 mark)
(b) Explain one difference between a LAN and a WAN. (2 lines) (1 mark)
24. Define the terms information system and communication system, and explain the relationship between them. (4 lines) (2 marks)
END OF 2000 PART B
1997 PART C Extended Answers
No Question!
END OF 1997 PART C
1998 PART C Extended Answers
Question 31 [7 marks]
(a) A particular World Wide Web (WWW) search engine has the following advanced search features:
abc AND xyz …returns documents which contain the character strings "abc" and "xyz" in the same paragraph.
abc OR xyz …returns the documents which contain either character strings "abc" or "xyz" or both in the same paragraph.
"abc xyz pqr" Use of the quotation marks returns documents which contain the exact phrase "abc xyz pqr".
abc CLOSE(10) xyz …returns documents which contain the character strings "abc" and "xyz" in the same paragraph as long as the strings are close by. In this example, within 10 words.
abc AND (xyz OR pqr) Use of the parentheses allows for the logical grouping of commands. In this case the documents would either contain the character strings "abc" and "xyz", or the strings "abc" and "pqr".
abc NOT xyz …returns documents that contain the character string "abc" but do not contain the string "xyz".
Note: All the search engine command words (AND, OR, CLOSE and NOT) must be entered in uppercase. Apart from the command words, the search engine is not case sensitive.
What search strings would you enter to retrieve documents available on the WWW, which target the following topics? Your search string should minimise the likelihood of the search engine retrieving documents unrelated to the specified topic.
(i) A dessert recipe that includes watermelon, rock melon and ice-cream. (Note: Another name for rock melon is cantaloupe, and ice-cream is sometimes spelt ice cream or icecream.) (2 lines available) [1 mark](ii) Information about Gary Larson the cartoonist renowned for drawing The Far Side - a cartoon strip syndicated in newspapers around the world. (2 lines available) [1 mark]
(iii) Information about other men named Gary Larson who are not cartoonists. (2 lines available) [1 mark]
(b) The following all play an important role in allowing someone to access the World Wide Web from their home computer.
- Browser
- URL
- IP address
- DNS (Domain Name Server)
- ISP (Internet Service Provider)
- TCP/IP
- Modem
- PSTN
Describe the role of each in enabling a student to retrieve information stored on a WWW server in Oxford, England, from her home computer in Western Australia. (16 lines available) [4 marks]
END OF 1998 PART C
1999 PART C Extended Answers28. CC Design Studio (15 marks)
Lee works as a graphic designer at the CC Design Studio. Lee uses a computer for all the studio’s graphics and makes extensive use of the Internet for communication with the studio’s clients. At present, Lee is working on a suite of graphics for use on a Government web-site. If the Government department likes Lee’s work, the CC Design Studio will win a lucrative contract.(a) To access the Internet, Lee’s computer has a static IP address and uses TCP/IP as well as HTML.
Explain the roles of IP addresses, TCP/IP and HTML that enables Lee to use the Internet’s World Wide Web. (18 lines) (6 marks)
(b) The newly created designs are responsible for the competitive advantage of CC Design Studio. Mindful of this, the directors have identified 3 major threats to this property:
- • Computer viruses
- • Hardware failure
- • Unauthorised access by competitors
For each of these perceived threats:
(i) Explain how problems could arise (7 lines) (3 marks)(ii) Indicate what CC Design could do to minimise the chances of these problems occurring. (7 lines) (3 marks)
(iii) In the event that these problems occur, indicate what CC Design could do to reduce their effects. (7 lines) (3 marks)
END OF 1999 PART C
2000 PART C Extended Answers
28. (7 marks)
Big Bank Electronic Banking CorporationBIG BANK is an electronic banking corporation with one million customers. BIG BANK headquarters is located in Canberry and there is a branch in each state capital. Headquarters and branches all operate their own networks locally and communicate with each other via the BIG BANK network that extends nation-wide.
There is a BIG BANK Call Centre in Canberry to answer customer queries nation-wide.
Customers may request phone and online service 24 hours per day. There are no local branches in the suburbs or in the country because all transactions are completed electronically via automatic teller machines, phone banking and over the Internet. It is almost a cashless society and customers may top up their electronic cash cards using electronic funds transfer at point of sale machines at most retailers and at automatic teller machines.(a) BIG BANK assures its customers that their personal data and banking transactions remain private.
Identify two concerns its customers may have about the storage of their details. (5 lines) (2 marks)(b) Describe two practices that BIG BANK may employ to ensure the security of customer data during storage and transmission on its electronic networks. (5 lines) (2 marks)
(c) Explain why most customers need a modem to participate in online banking from home. (3 lines) (1 mark)
(d) Communications media used for data transmission include Fibre Optic cable and Unshielded Twisted Pair (Category 2) cable.
Which of these would be suitable for transmission of BIG BANK data both within a local branch and nation-wide?Give three reasons why you chose this medium. (6 lines) (2 marks)
END OF 2000 PART C
2001 PART C Extended Answers