Computer Science 2210 XI Worksheet -Mock 2015.pdf

Computer Studies 2210 March, 2015 Worksheet

Page No. 1 of 15

Question 1 What is bespoke soft ware and what are its advantages and disadvantages compared to generic application soft ware? Question 2 Connect the task on the left to the most appropriate type of soft ware on the right.

Question 3 Robots are used to do many jobs.

a. Describe a job and say why robots are used to do it. (Job & Reason) b. Describe two jobs which robots cannot do. (Jobs & Reasons)

Question 4 Computer-aided design (CAD) is one of the most widely used commercial applications of computer graphics.

a. Name two areas in which CAD could be used. b. Give three features you might expect a CAD program to contain.


Page No. 2 of 15

Question 5 An estate agent uses a computer system to store details about properties for sale. A section of the properties file is shown below:

a. Why is coded data used for Type? b. What is the data type for Price? c. What is meant by a key field? Which is the key field?

Question 6 A second-hand bookstore has 2000 books and magazines in stock. Each item has a unique five-digit code with the first digit identifying the type of item:

1 = hardback non-fiction 2 = hardback fiction 3 = paperback 4 = magazine 5 = comic book

For example, in the code 10379 the 1 identifies that it is a hardback non-fiction book; in the code 41055 the 4 identifies the item as a magazine. Write an algorithm, using pseudocode or otherwise, that:

inputs the codes for all 2000 items

validates the input code

calculates how many of each category are in stock

outputs the five totals.


Page No. 3 of 15

Question 7 Explain the following terms:

a. Database b. file c. direct access file d. record e. sequential file

Question 8

a. What is meant by the term validation? b. What is meant by the term verification? c. Describe one method of verification when changing a password.

Question 9 In a chemical plant, the temperature is taken at the start and end of each batch and the volume of gas are measured. The following spreadsheet shows a set of measurements.

A B C D D F

1

Batch

Start temperature

End temperature

Temp rise

Gas volume

Volume/ temp rise

2 11 16 28 12 60 5.0

3 12 20 35 15 80 5.3

4 13 15 30 15 75 5.0

5 14 19 33 14 90 6.4

6 15 18 36 18 100 5.6

7 16 17 35 18 110 6.1

8 17 20 38 18 105 5.8

9 18 21 37 16 100 6.3

10 Mean temperature rise = 15.75 Maximum ration 6.4

a. What is the formula to find the temperature rise for Batch 15? b. What is the formula to find the mean (average) temperature rise for all the batches? c. What is the formula for the maximum ratio? d. How can you repeat the formula in F2 in cells F3 to F9 without typing it out another seven

times? Question 10 Define the term backing storage and explain why computers need backing storage. Question 11 ROM and RAM are two types of memory found in computers.

a. What do the letters ROM stand for? b. What do the letters RAM stand for? c. What is the main difference between RAM and ROM?


Page No. 4 of 15

d. Complete the following statements with RAM, ROM, backing storage. i. .......... stores a copy of your work when the computer is switched off .

ii. .......... stores application programs and data while the computer is running. iii. .......... stores programs that must be available as soon as the computer is switched on.

Question 12 The following algorithm accepts 30 test scores and outputs the smallest, the largest and the average.

10 Largest 0

20 Smallest 0

30 Total 0

40 FOR x 0 TO 30

50 INPUT Score

60 Total Total + Score

70 IF Score > Largest THEN Largest Score

80 IF Score < Smallest THEN Smallest Score

90 x x + 1

100 NEXT

110 OUTPUT Largest, Smallest, Total / x

There are three errors in this algorithm. Locate these errors and suggest what changes should be made to the algorithm. (Errors and Corrections) Question 13 Describe the features of:

a. a command line interface; b. a graphical user interface.

Question 14 Draw a diagram to explain how folders are structured on a hard disk. Question 15 Explain the meaning of these computer terms:

a. buffer b. peripheral device c. interrupt d. polling e. handshaking


Page No. 5 of 15

Question 16 Copy and complete the truth table for the following logic circuit:

A B C X

Question 17 Describe a batch processing system, using the example of a specific application. Question 18 Consider the following flowchart: Create a trace table for the flowchart if the values of s input are: 30, 6, 60, 45, 60, 15, 30, 30, 15, 12 x s Result Output


Page No. 6 of 15

Question 19 Describe three network topologies, including a sketch Question 20

a. What is an intranet and why is it used? b. What is the difference between an intranet and the Internet?

Question 21 Onboard computers allow aeroplanes to operate more efficiently and safely.

a. How is data collected during a flight? b. Describe how the computer would know when to make course corrections during a flight. c. Give two advantages of a computer system over a human pilot. d. Why do all flights still have human pilots?

Question 22 Name the stages of the system life cycle. Question 23 A regional boiler repair company with four branches wants to change from a manual stock control system to a computerised stock control system.

a. State three reasons why the manager would want a computerised system. b. Describe three methods of fact finding that would be used to analyse the manual stock control

system. Question 24 A small business has decided to change from a manual wages system to a computerised wages system for producing the employees pay.

a. State three tasks in the analysis of the existing system. b. State three types of test data that should be used to test the program. c. Name the three different types of system maintenance that might be required by the new

system. Question 25 Describe four methods of system implementation. For each method of implementation, identify a situation where it is most suitable. Question 26 Users of the Internet can save money compared to people who are not online. Give two examples of online services that allow users to save money and describe how the Internet has made these savings possible.


Page No. 7 of 15

Question 27 The e temperature and soil moisture of a greenhouse must be controlled and must remain within a certain range. The e temperature must be kept between 5C and 30C and the soil must not get too dry. Describe in detail how a computer system could be used to monitor and control both temperature and soil moisture in the greenhouse. In your answer state what items of hardware or equipment might be needed Question 28 Robots are now used in many different situations.

a. Name two different sensors that can be fitted to robots. b. Describe how each of these sensors could be used. c. List three jobs done by robots. d. Give three reasons for using robots instead of people.

Question 29 A multimedia presentation needs to use photographs taken by a digital camera. The photographs are transferred to a computer.

a. State two types of change that can be made to the photographs using graphics software. b. Describe how edited photographs can be inserted into the presentation. c. State one multimedia element, other than graphics and text that could be included in the

presentation. Question 30 A spreadsheet could be used to produce a simulation model.

a. Give a definition of a simulation model and state one example of where a simulation model could be used.

b. Give an advantage of using a simulation model. Question 31 A number of schools are considering using video conferencing.

a. What is meant by video conferencing? b. The schools already have computers. Give two additional pieces of hardware needed to enable

video conferencing. c. Give two advantages to the schools of using video conferencing.

Question 32 A manufacturer of digital cameras employs 12 people to answer technical queries over the telephone. The company has decided to develop a website to answer customer queries.

a. Describe two ways this change would affect the 12 employees. b. Describe two advantages to the company of introducing this system. c. Describe two advantages to the customer of using this system.


Page No. 8 of 15

Question 33 a. What is meant by soft ware copyright? b. Define the term computer virus. c. What is meant by the term de-skilling?

Question 34

a. What is meant by teleworking? b. What hardware and soft ware is needed by a teleworker? c. Give two advantages of teleworking for the employer. d. Give two advantages of teleworking for the employee.

Question 35 A doctors clinic decides to network its computers and allow Internet access on them. Patient records are stored on a computer linked to the network, to allow doctors to access information from any computer in the clinic.

a. Describe two problems this could create and how the system could be protected against these problems. (Problems and Protections)

b. How is it possible to prevent unauthorised access to patient records? c. Each patient record is approximately five megabytes. Suggest a possible backup device to

store the records. Question 36 List three principles on which data protection legislation is based. Question 37 Bytes of data transferred using a serial cable are checked for errors at the receiving end using an even/odd parity checks.

a) Suppose you are using an even parity. What should the binary word 1010 look like after

you add a parity bit? b) Suppose you are using an odd parity. What should the binary word 1010 look like after

you add the parity bit? c) How can any errors be corrected?


Page No. 9 of 15

Question 38 Consider the following algorithm.

a. Write down the output if the two numbers input are 4 and 3. (a = 4 and b = 3.)

b. Explain why an algorithm is written as a subroutine (procedure) and stored in a program library.

Question 39 Computer models are used to forecast the paths of hurricanes.

a. Describe how data is gathered for the computer model. b. How does the computer model make its forecast based on the input data? c. Describe two ways the forecast could be conveyed to the user.

Question 40 A student gave the following three computer definitions.

Give the name of the term being described in each case.

a. a signal from a device sent to a computer causing the CPU to stop its current operation

temporarily b. unique ID for a network interface card c. an exchange of signals between two devices when communicating to ensure

synchronisation d. numerical ID for each device on the Internet e. a temporary memory to store data waiting to be sent to a device


Page No. 10 of 15

Question 41 Read this algorithm. Set Result to 0 INPUT Number WHILE Number >= 0

DO IF Number > Result THEN Result Number INPUT Number

ENDWHILE OUTPUT Result

a. What is the purpose of this algorithm? b. What value of input will stop the loop and output the answer? c. Copy and complete the following trace table for the input values 6, 12, 8 and 3.

Question 42 Draw the logic circuit required to fulfill the following statements:

a. Output C = (NOT(A AND B)) AND (A OR B) b. Light (L) is on if Switch A is on OR (Switch B is on AND Input C is off ).

Question 43 Name two household devices that are controlled by a microprocessor and do not need an operating system. For each, explain why an operating system is not necessary.


Page No. 11 of 15

Question 44 Consider the following


Page No. 12 of 15

Complete the following trace table using the temperature values 14, 17, 23, 27, 29, 30, 32, 26, 18, 12.

Question 45 A piece of pseudocode was written to input 1000 positive numbers and then output the highest and lowest numbers.

10 highest = 0 20 lowest = 0 30 for count = 1 to 100 40 input number 50 if number > highest then number = highest 60 if number < lowest then number = lowest 70 count = count + 1 80 next counts 90 print highest, lowest

There are errors in the code. Locate these errors and suggest a correction. Question 46 A country has four mobile phone network operators. Each mobile phone number has eight digits. The first three digits identify the network operator:

444 Yodafone 555 N2 network 666 Kofee mobile 777 Satsuma mobile

Write an algorithm, using pseudocode or flowchart only, which reads 50 000 eight-digit mobile phone calls made during the day and outputs the number of calls made on each of the four networks.


Page No. 13 of 15

Question 47 Some decorative lights are made up from a cluster of red, blue, green, yellow and white LEDs. Each colour is represented by a binary code:

A 6-bit register, R1, stores the 1-values to represent a sequence of colours. Thus, if R1 contains:

this means the blue, yellow and black colour sequence is stored and displayed in that order. The length of time each light is on is set by a binary value in another register, R2: Thus

means each colour is on for 2 seconds.

a. The two registers contain the following values. What is the sequence of coloured lights and the timing for each colour?

b. What will the two registers contain if the coloured light sequence is red, green and black and the timing is 5 seconds?

c. What is the problem with trying to display green, blue, red in that order?


Page No. 14 of 15

Question 48 a. Show whether the following identification numbers are valid or not. You must show how you

arrived at your answer with the help of 11s method. I. 4 2 1 9 2 3

II. 8 2 0 1 5 6 b. Find the check digit for the following identification number:

5 0 2 4 1 __

Question 49 A floor turtle can use the following instructions:

(Each square in the drawing below is 10 cm by 10 cm.)

Complete the set of instructions to draw the above shape (shown in bold lines) using REPEAT at least once.


Page No. 15 of 15

Question 50 A town contains 5000 houses. Each house owner must pay tax based on the value of the house. Houses over $200 000 pay 2% of their value in tax, houses over $100 000 pay 1.5% of their value in tax and houses over $50 000 pay 1% of their value in tax. All others pay no tax. Write an algorithm to solve this problem. (Solve this algorithm with the help of WHILEDO loop). Question 51 a. The systems analyst needs to ensure that the project is delivered on time and on .budget. Explain

why the systems analyst has chosen to use a Gantt chart rather than a PERT chart to track the progress of this project.

b. The systems analyst has decided to use the following methods to gather information about the existing manual system.

A questionnaire for the parents

An interview for the school office staff Explain why each of the methods used was appropriate for this manual system.

Question 52 The rail network consists of 10 stations. The fare between each station is $2. There is a 10% discount when 3 or more passengers travel together. Tickets can be purchased at any station using automated terminals. Write an algorithm for the automated terminals to:

input the starting station number, the destination station number and the number of passengers

calculate the total fare and output the amount to be paid

calculate the change (if any)

issue the rail ticket(s) and change (Solve this algorithm with the help of REPEATUNTIL and FORNEXT loop). Question 53 A user wishes to use a word processing application. They can either use a command line interface (CLI) or a graphical user interface (GUI) to open this application.

a) Describe how both methods could be used to select the application including any input hardware needed.

b) What is meant by automatic data capture? c) Name a device used in automatic data capture and describe an application that uses it

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Computer Science 2210 XI Worksheet -Mock 2015.pdf