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M.Mushtaq LGS,GSIS,Apples

IGCSE/O-Level

Computer Science 0478/2210

Past Papers/Mark Schemes 2009-2014

For more notes and papers

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Syllabus content at a glance

6 Cambridge O Level Computer Science 2210. Syllabus for examination in 2015.

3. Syllabus content at a glance

All candidates study the following topics.

Sections Topics

Section 1 Theory of Computer Science

1.1 Data representation

1.1.1 Binary systems

1.1.2 Hexadecimal

1.1.3 Data storage

1.2 Communication and Internet technologies

1.2.1 Serial and parallel data transmission

1.2.2 Security aspects

1.2.3 Internet principles of operation

1.3 Hardware and software

1.3.1 Logic gates

1.3.2 Computer architecture and the fetch-execute cycle

1.3.3 Input devices

1.3.4 Output devices

1.3.5 Memory, storage devices and media

1.3.6 Operating systems

1.3.7 High- and low-level languages and their translators

1.4 Security

1.5 Ethics

Section 2 Practical Problem-solving and Programming

2.1 Algorithm design and problem-solving

2.1.1 Problem-solving and design

2.1.2 Pseudocode

2.2 Programming

2.2.1 Programming concepts

2.2.2 Data structures; arrays

2.3 Databases

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Assessment at a glance

7Cambridge O Level Computer Science 2210. Syllabus for examination in 2015.

4. Assessment at a glance

For Cambridge O Level Computer Science, candidates take two components: Paper 1 and Paper 2.

Components Weighting

Paper 1: Theory 1 hour 45 minutes

This written paper contains short-answer and structured questions. There is no choice of questions.

No calculators are permitted in this paper.

75 marks

Externally assessed.

60%

Paper 2: Problem-solving and Programming 1 hour 45 minutes

This written paper contains short-answer and structured questions. There is no choice of questions. 20 of the marks for this paper are from questions set on the pre-release material.1

No calculators are permitted in this paper.

50 marks

Externally assessed.

40%

AvailabilityThis syllabus is examined in the June and November examination series.

This syllabus is available to private candidates.

Detailed timetables are available from www.cie.org.uk/examsofficers

Centres in the UK that receive government funding are advised to consult the Cambridge website www.cie.org.uk for the latest information before beginning to teach this syllabus.

Combining this with other syllabusesCandidates can combine this syllabus in an examination series with any other Cambridge syllabus, except:

• syllabuses with the same title at the same level

• 0478 Cambridge IGCSE Computer Science

Please note that Cambridge O Level, Cambridge IGCSE and Cambridge International Level 1/Level 2 Certificate syllabuses are at the same level.

1 The pre-release material will be made available to Centres six months before the examination. It will also be reproduced in the question paper. Candidates are not permitted to bring any prepared material into the examination.

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Syllabus content


6. Syllabus content

Section 1 Theory of Computer Science1.1 Data representation

Candidates should be able to:

1.1.1 Binary systems

• recognise the use of binary numbers in computer systems

• convert denary numbers into binary and binary numbers into denary

• show understanding of the concept of a byte and how the byte is used to measure memory size

• use binary in computer registers for a given application (such as in robotics, digital instruments and counting systems)

1.1.2 Hexadecimal

• represent integers as hexadecimal numbers

• show understanding of the reasons for choosing hexadecimal to represent numbers

• convert positive hexadecimal integers to and from denary

• convert positive hexadecimal integers to and from binary

• represent numbers stored in registers and main memory as hexadecimal

• identify current uses of hexadecimal numbers in computing, such as defining colours in Hypertext Markup Language (HTML), Media Access Control (MAC) addresses, assembly languages and machine code, debugging

1.1.3 Data storage

• show understanding that sound (music), pictures, video, text and numbers are stored in different formats

• identify and describe methods of error detection and correction, such as parity checks, check digits, checksums and Automatic Repeat reQuests (ARQ)

• show understanding of the concept of Musical Instrument Digital Interface (MIDI) files, jpeg files, MP3 and MP4 files

• show understanding of the principles of data compression (lossless and lossy compression algorithms) applied to music/video, photos and text files

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Syllabus content


1.2 Communication and Internet technologies


1.2.1 Serial and parallel data transmission

• show understanding of what is meant by transmission of data

• distinguish between serial and parallel data transmission

• show understanding of the reasons for choosing serial or parallel data transmission

• show understanding of the need to check for errors

• explain how parity bits are used for error detection

• identify current uses of serial and parallel data transmission, such as Integrated Circuits (IC) and Universal Serial Bus (USB)

1.2.2 Security aspects

• show understanding of the security aspects of using the Internet and understand what methods are available to help minimise the risks

• show understanding of the Internet risks associated with malware, including viruses, spyware and hacking

• explain how anti-virus and other protection software helps to protect the user from security risks (this also links into section 1.4 of the syllabus)

1.2.3 Internet principles of operation

• show understanding of the role of the browser and Internet server

• show understanding of what is meant by hypertext transfer protocol (http) and HTML

• distinguish between HTML structure and presentation

• show understanding of the concept of MAC address, Internet Protocol (IP) address and cookies

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1.3 Hardware and software


1.3.1 Logic gates

• use logic gates to create electronic circuits

• understand and define the functions of NOT, AND, OR, NAND, NOR and XOR (EOR) gates, including the binary output produced from all the possible binary inputs (all gates, except the NOT gate, will have 2 inputs only)

• draw truth tables and recognise a logic gate from its truth table

• recognise and use the following standard symbols used to represent logic gates:

NOT AND OR NAND NOR XOR

• produce truth tables for given logic circuits, for example:a b c out0 0 0 0 0 1 0 1 0 0 1 1 1 0 0 1 0 1 1 1 0 1 1 1

• produce a logic circuit to solve a given problem or to implement a given written logic statement, such as IF (switch A is NOT on) OR (switch B is on AND switch C is NOT on) then alarm, X, sounds

1.3.2 Computer architecture and the fetch-execute cycle

• show understanding of the basic Von Neumann model for a computer system and the stored program concept (program instructions and data are stored in main memory and instructions are fetched and executed one after another)

• describe the stages of the fetch-execute cycle

1.3.3 Input devices

• describe the principles of operation (how each device works) of a range of input devices including 2D and 3D scanners, barcode readers, digital cameras, keyboards, mice, touch screens, microphones

• describe how these principles are applied to real-life scenarios, for example: scanning of passports at airports, barcode readers at supermarket checkouts, and touch screens on mobile devices

• describe how a range of sensors can be used to input data into a computer system, including light, temperature, magnetic field, gas, pressure, moisture, humidity, pH/acidity/alkalinity and motion/infra-red

• describe how these sensors are used in real-life scenarios, for example: street lights, security devices, pollution control, games, and household and industrial applications

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1.3.4 Output devices

• describe the principles of operation of a range of output devices, including: inkjet, laser and 3D printers; 2D and 3D cutters; speakers and headphones; actuators; flat-panel display screens, including Liquid Crystal Display (LCD) and Light-Emitting Diodes (LED); and LCD projectors and Digital Light Projectors (DLP)

• describe how these principles are applied to real-life scenarios for example: printing single items on demand or in large volumes; banks of digital displays; use of small screens on mobile devices; smart boards

1.3.5 Memory, storage devices and media

• show understanding of the difference between: primary, secondary and off-line storage and provide examples of each, such as, primary: Read Only Memory (ROM), Random Access Memory (RAM) and DVD-RAM; secondary: hard disk drive (HDD) and Solid State Drives (SSDs); off-line: Digital Versatile Disks (DVDs), Compact Disks (CDs), Blu-ray, USB flash memory and removable disks

• describe the principles of operation of a range of types of storage devices and media including magnetic, optical and solid state

• describe how these principles are applied to currently available storage solutions, such as SSDs, hard disk drives, USB flash memory, DVDs, CDs and Blu-ray

• calculate the storage requirement of a file

1.3.6 Operating systems

• describe the purpose of an operating system

• show understanding of the need for interrupts

1.3.7 High- and low-level languages and their translators

• show understanding of the need for both high-level and low-level languages

• show understanding of the need for compilers when translating programs written in a high-level language

• show understanding of the use of interpreters with high-level language programs

• show understanding of the need for assemblers when translating programs written in assembly language

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1.4 Security


1.4.1

• show understanding of the need to keep data safe from accidental damage, including corruption and human errors

• show understanding of the need to keep data safe from malicious actions, including unauthorised viewing, deleting, copying and corruption

1.4.2

• show understanding of how data are kept safe when stored and transmitted, including:

○ use of passwords, both entered at a keyboard and biometric ○ use of firewalls, both software and hardware, including proxy servers ○ use of Secure Socket Layer (SSL) ○ use of symmetric encryption (plain text, cypher text and use of a key) showing understanding

that increasing the length of a key increases the strength of the encryption

1.4.3

• show understanding of the need to keep online systems safe from attacks including denial of service attacks, phishing, pharming

1.4.4

• describe how the knowledge from 1.4.1, 1.4.2 and 1.4.3 can be applied to real-life scenarios including, for example, online banking, shopping

1.5 Ethics


• show understanding of computer ethics, including copyright issues and plagiarism

• distinguish between free software, freeware and shareware

• show understanding of the ethical issues raised by the spread of electronic communication and computer systems, including hacking, cracking and production of malware

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Section 2 Practical Problem-solving and Programming2.1 Algorithm design and problem-solving


2.1.1 Problem-solving and design

• show understanding that every computer system is made up of sub-systems, which in turn are made up of further sub-systems

• use top-down design, structure diagrams, flowcharts, pseudocode, library routines and sub-routines

• work out the purpose of a given algorithm

• explain standard methods of solution

• suggest and apply suitable test data

• understand the need for validation and verification checks to be made on input data (validation could include range checks, length checks, type checks and check digits)

• use trace tables to find the value of variables at each step in an algorithm

• identify errors in given algorithms and suggest ways of removing these errors

• produce an algorithm for a given problem (either in the form of pseudocode or flowchart)

• comment on the effectiveness of a given solution

2.1.2 Pseudocode

• understand and use pseudocode for assignment, using ←

• understand and use pseudocode, using the following conditional statements:

IF … THEN … ELSE … ENDIF

CASE … OF … OTHERWISE … ENDCASE

• understand and use pseudocode, using the following loop structures:

FOR … TO … NEXT

REPEAT … UNTIL

WHILE … DO … ENDWHILE

• understand and use pseudocode, using the following commands and statements:

INPUT and OUTPUT (e.g. READ and PRINT)

totalling (e.g. Sum ← Sum + Number)

counting (e.g. Count ← Count + 1)

(Candidates are advised to try out solutions to a variety of different problems on a computer using a language of their choice; no particular programming language will be assumed in this syllabus.)

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2.2 Programming


2.2.1 Programming concepts

• declare and use variables and constants

• understand and use basic data types: Integer, Real, Char, String and Boolean

• understand and use the concepts of sequence, selection, repetition, totalling and counting

• use predefined procedures/functions

2.2.2 Data structures; arrays

• declare the size of one-dimensional arrays, for example: A[1:n]

• show understanding of the use of a variable as an index in an array

• read values into an array using a FOR … TO … NEXT loop

2.3 Databases


• define a single-table database from given data storage requirements

• choose a suitable primary key for a database table

• perform a query-by-example from given search criteria

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© UCLES 2009 7010/01/M/J/09

For

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14 Study the flowchart very carefully.

START

STOP

T = 1

INPUT N

X = 1

T = T * X

X = X + 1

Is X =N + 1?

OUTPUT T

A

B

Yes

No

(a) Complete the table to show what outputs you would expect for the two inputs.

Input N Output T

5

1

[2] (b) Write down a possible LOOP construct for the section A to B in the flowchart using

pseudocode.

[2]

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© UCLES 2009 7010/01/M/J/09 [Turn over

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15 Aeroplanes use on-board computer power to allow them to operate more efficiently and safely.

(a) How is data during a flight collected and fed back to on-board computers?

[2]

(b) Why are computer systems thought to be safer than human pilots?

[2]

(c) However, pilots are still used on all flights. Why is this?

[2]

(d) What recent developments have led to more use of computer control in newly designed

aeroplanes?

[1]

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(e) Describe how the computer would know when to make course corrections during a flight.

[2]

(f) At the airport, baggage check-ins use bar codes which are read by computers. (i) What information would be stored on the bar code?

[1]

(ii) Why do airports use the bar codes on baggage?

[1]

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16 The following flowchart shows what happens when a customer uses a credit card to pay for goods at a supermarket. Ten of the boxes are blank.

Using the items from the list, insert the ten missing statements using the appropriate number only. Each statement may be used once only.

START

STOP

STOP

Insert credit card

Type in PIN

Yes

Yes

No

Yes

Yes

No

No

No

1 are PIN details correct?2 are there sufficient funds?3 card removed4 end transaction5 is expiry date exceeded?6 is card reported stolen?7 money transfer takes place8 print itemised bill9 read credit card details10 two computers communicate

LIST OF STATEMENTS

[5]

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© UCLES 2009 7010/01/M/J/09

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17 A car sales company uses a database. Here are three tables from the database: New Car Sales

Customer Reference

Car Ordered Specification Delivery Date

151319 Cancelled order None Not applicable

162154 VW Golf 21215168 December 2008

171216 BMW 320i 07981624 February 2009

Customer Details

Customer Reference

Customer Name Customer Address Trade In?

141516 J Smith 7 Toll Road No

151319 M Kyle 14 Coast Road No

162154 D Khan 19 Main Street Yes

165196 S Gogic 555 Trabant Road No

171216 D Marques 21 Lakki Harbour Yes

Car Manufacturer

Specification Car Description List of Extras Cost Price ($)

07981624 BMW 320i C N O R V Z 48 500

21151198 VW Golf A B C E T U 16 200

21215168 VW Golf B D E F J L 21 000

31311115 Ford Focus A P R S W 17 000

(a) How many records are shown in the Customer Details table?

[1]

(b) (i) Which field connects the New Car Sales table with the Customer Details table?

[1]

(ii) Which field connects the New Car Sales table with the Car Manufacturer table?

[1]

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(c) Give two reasons why List of Extras in the Car Manufacturer table is stored in code form.

1

2

[2]

(d) A customer goes into the showroom and the salesperson keys in 162154. What fields

and information would be shown on the output screen?

[2]

(e) Give one advantage to the car sales company of holding customer information on a

database.

[1]

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Permission to reproduce items where third party owned material protected by copyright is included has been sought and cleared where possible. Every reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity.

University of Cambridge International Examinations is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge.

© UCLES 2009 7010/01/M/J/09

For

Examiner's

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18 A small airport handles 400 flights per day from three airlines:

FASTAIR (code FA) SWIFTJET (code SJ) KNIGHTAIR (code KA)

Each flight is identified by the airline code and 3 digits. For example FA 156.

Write an algorithm, using pseudocode or otherwise, which monitors the 400 flights into and out of the airport each day. The following inputs, processing and outputs are all part of the monitoring process:

• input flight identification

• calculate number of flights per day for each of the three airlines

• output the percentage of the total flights per day by each airline

• any validation checks must be included

[5]

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Mark Scheme: Teacher version Syllabus Paper

GCE O Level – May/June 2009 7010 01

© UCLES 2009

(ii) any one from: tracking/uniquely identifies baggage/ensures baggage gets to right place increased security links to passenger/ensures luggage cannot travel without passenger [1] 16

[5]

START

STOP

Insert credit card

Type in PIN

STOP

No

Yes

Yes

Yes

No

No

No

Yes

1 4

10

9

5/6

6/5

2

7

3 8

(1 mark)

(1 mark)

(1 mark)

(1 mark)

(1 mark)

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© UCLES 2009

17 (a) 5 [1] (b) (i) Customer Reference (ii) Specification [2] (c) any two from: reduces typing errors uses less memory faster to type in quicker to sort store in one field easier to validate [2] (d) Car Description/Car Ordered VW Golf } Delivery Date Dec 2008 } New Car Sales Specification 21215168 } Customer Name D Khan } Customer Address 19 Main Street } Customer Details Trade In Yes } (1 mark 1 field name and contents from New Car Sales table plus 1 field name and

contents from Customer Details table) List of Extras B D E F J L } Cost Price ($) 21 000 } Car Manufacturer (1 mark 1 field name and contents from Car Manufacturer table) [2] (e) any one advantage from: later use if customer wants to trade in again in 2 or 3 years’ time can send out new product information if safety/recall issues from car manufacturers service/safety check reminders [1] 18 marking points (1 mark per item up to the maximum of 5): initialise fa, sj and ka to zero correct loop inputs (in correct place) addition of number of flights per airline any validation checks carried out calculate percentages outputs (in correct place and ONLY if some evidence of any attempt at processing)

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© UCLES 2009

sample program/algorithm fa = 0; sj = 0; ka =0; } 1 mark for x = 1 to 400 } 1 mark input lettercode } } 1 mark input numbercode } if lettercode = “FA” then fa = fa + 1 } } if lettercode = “SJ” then sj = sj + 1 } 1 mark } if lettercode = “KA” then ka = ka + 1 } else print “error” } 1 mark next x fapercent = fa/4 } } sjpercent = sj/4 } 1 mark } kapercent = ka/4 } print fapercent, sjpercent, kapercent } 1 mark [5]

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© UCLES 2009

Sample flowchart:

START

Input lettercode

Input numcode

fa = fa+1

sj = sj+1

ka = ka+1

Is lettercode = FA

Is lettercode = SJ

Is lettercode = KA

Output “error”

Is x

© UCLES 2009 7010/01/O/N/09

For

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9 Study the flowchart.

START

STOP

C = 1

INPUT N

C = C + 1

N = N/10

IsN < 1? OUTPUT C

No

Yes

Complete the table to show what outputs you would expect for the three inputs.

INPUT N OUTPUT C

55

2100

1

[3]

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© UCLES 2009 7010/01/O/N/09 [Turn over

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10 Houses for sale can be viewed using a Virtual Reality Tour. This takes you round the house in three dimensions (3D) on a computer screen “as if you were there in person”.

(a) Give two advantages of Virtual Reality Tours.

1

2

[2]

(b) How are the house images created for the Virtual Reality Tour?

[2]

(c) What two changes in technology have allowed Virtual Reality Tours to become

possible?

1

2

[2]

(d) Describe a typical tool on a Virtual Reality Tour web page.

[1]

(e) Give another application of Virtual Reality Tours.

[1]

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© UCLES 2009 7010/01/O/N/09

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11 A spreadsheet has been set up to store results of football matches for 12 teams. Halfway through the year the results were:

(a) What formula is in cell E4 to calculate the Number of Points for United?

[1]

(b) Goal Difference = (Goals For – Goals Against). What formula is in cell H4 to find Goal

Difference for United?

[1]

A B C D E F G H I

1

2

Team Name

Won (3 points)

Drawn (1 point)

Lost (0 points)

Number of Points

Goals For

Goals Against

Goal Difference

MatchesPlayed

3

4 United 7 2 2 23 16 4 12 11

5 City 7 2 2 23 21 10 11 11

6 Town 6 1 4 19 16 10 6 11

7 Academics 4 6 1 18 12 9 3 11

8 Rovers 4 4 3 16 16 14 2 11

9 Runaways 3 5 3 14 10 12 -2 11

10 Yorkers 3 5 3 14 10 14 -4 11

11 Albion 3 3 5 12 14 15 -1 11

12 Knights 4 0 7 12 10 18 -8 11

13 Sporting 2 5 4 11 10 12 -2 11

14 Nohopers 2 3 6 9 8 16 -8 11

15 Jokers 2 2 7 8 6 14 -8 11

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(c) State two ways of checking the correctness of data in columns F and G.

1

2

[2]

(d) Rovers played Yorkers and won 2 – 0. Columns B, D, F, G and I were updated. Which

other cells would be automatically updated?

[2]

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© UCLES 2009 7010/01/O/N/09

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13 A radio station keeps a database of all its music CDs. Here is part of this database:

Reference Number

CD title number of

tracks special edition

CD length (mins)

number of hit tracks

1111 Afternoon Glory 12 N 55 1

1112 Stone Tulips 10 N 42 3

1113 Aftermath 8 N 33 0

1114 Major Peppers 15 Y 72 5

1115 Seaside 9 N 40 2

1116 Lookout 12 N 62 2

1117 Future Dreams 11 N 60 3

1118 Moonlight 14 Y 70 2

(a) How many records are there in the database section?

[1]

(b) If the following query was input:

(CD length (mins) < 60) AND (number of hit tracks > 1)

using Reference Number only, write down which data items would be output.

[1]

(c) Write down a query to select which CDs are special edition or have more than 10 tracks.

[2]

(d) The database is sorted in descending order on CD length (mins). Using Reference

Number only, write down the order of the records following this sort.

[1]

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17 (a) A car’s speed is measured between points A and B, which are 200 km apart.

A B

200 km

The final speed of the car is calculated using the formula:

What is the final speed of a car if it takes 2 hours to get from A to B?

[1]

Part (b) is on the next page.

200 Final Speed = ──────── Time (hours)

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Permission to reproduce items where third party owned material protected by copyright is included has been sought and cleared where possible. Every reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity.

University of Cambridge International Examinations is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge.

© UCLES 2009 7010/01/O/N/09

For

Examiner's

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(b) Write an algorithm, using pseudocode or otherwise, which inputs the times for 500 cars, calculates the final speed of each car using the formula in part (a), and then outputs:

• the final speed for ALL 500 cars

• the slowest (lowest) final speed

• the fastest (highest) final speed

• the average final speed for all the cars.

[6]

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Mark Scheme: Teach s’ version Syllabus Paper

GSE O LEVEL – October/November 2009 7010 01

© UCLES 2009

(e) Any one from: e.g. inside chemical plants inside nuclear plants/reactors hotels games training interactive mapping museums [1] 11 (a) (E4) (=) B4 * 3 + C4 (B4*3 + C4*1 + D4*0 also correct) [1] (b) (H4) (=) F4 – G4 [1] (c) Any two from: validation checks - no negative numbers - whole numbers only - no letters/type check - range check check if sum of numbers in column G = sum of numbers in column F check if the sum of the numbers in column H = 0 [2] (d) E8, H8, E10, H10 ← 1 mark → ← 1 mark → columns E and H (1 mark only) [2] 12 (a) Any one from: infra-red sensors (to detect movement) ADC (in case sensors are analogue) [1] (b) Any one from: need analogue signal to operate camera motors to move lens/camera computer output is digital [1] (c) Any one from: movement detected computer compares new image with last image images are stored and played back later [1]

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© UCLES 2009

(d) Any two from: no film processing to be done/doesn’t run out of film/cost of buying film instantaneous checks camera won’t need manual emptying [2] (e) (i) 400/0.4 = 1000 images alternative answer 400/0.0004 = 1 000 000 images approx (1 048 576 exactly) [1] (ii) store images on another hard drive or on DVD/CDs archive old images [1] 13 (a) 8 [1] (b) 1112, 1115 [1] (c) (special edition = “Y“) OR (number of tracks > 10) < ─ ─ ─1 mark ─ ─ ─> < ─ ─ ─ ─1 mark ─ ─ ─ ─> (number of tracks > 10) OR (special edition = “Y“) < ─ ─ ─1 mark ─ ─ ─> < ─ ─ ─ ─1 mark ─ ─ ─ ─> [2] (d) 1114, 1118, 1116, 1117, 1111, 1112, 1115, 1113 [1] (e) (i) Any one from: (auto capture) on the database itself transaction file spreadsheet [1] (ii) link through the reference number/CD title/primary key [1] 14 Any four points from: get information from experts input data into knowledge base create rules base create inference engine create human-machine interface/question and answer sessions firstly test system with “known” problems and solutions create output system screen/format create/design validation routines [4]

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© UCLES 2009

15 (a) TAB: 0 1 1 1 0 1 FRET: 0 1 0 0 1 0 [2] (b) (i)

[1] (ii) 19 [1] (c) Any two from: can store music directly onto digital, optical media/mp3 players easy to modify music by simply changing binary values easy to teach somebody how to play an instrument easy to convert music for other instruments allows auto play back through interfaces uses less memory [2] 16 (a) Any two from: eliminates ticket fraud can’t get lost (in the post)/sent to wrong address easier to amend flight details (no tickets to re-print) reduces booking expenses faster processing can check-in from anywhere (therefore saving queuing time at airport) [2] (b) Any two from: computer crashes (therefore “disappearing reservation” – in such cases, paper tickets are

better) e-tickets not “portable” between airlines whereas paper tickets are human confidence – prefer to have “proof” of booking with paper ticket [2]

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© UCLES 2009

(c) Any two from e.g. destination airport starting airport name(s) of passenger(s) passport number/nationality special requirements number of passengers dates/times of flights cost of tickets full flight itinerary special offers information about the airlines information about flight facilities sort on cheapest/fastest routes/flights ability to check availability of flights/search for flights terms and conditions [2] 17 (a) 100 (km/hr) [1] (b) Marking points Initialisation (slowest = 1000 or an equivalent high value) Correct loops structure and control Input (in correct place) Calculation of final speed using given formula in part (a) inside the loop Output the final speed for ALL cars inside the loop Calculation highest speed input Calculation slowest speed input Calculate the average (two parts to this calculation) Final outputs (correct place + some form of processing done) [6] Sample program: total = 0 } highest = 0 } 1 mark slowest = 1000 } for n = 1 to 500 } 1 mark input time } 1 mark finalspeed = 200/time } 1 mark print finalspeed } 1 mark total = total + finalspeed if finalspeed > highest } then highest = finalspeed } 1 mark if finalspeed < slowest } then slowest = finalspeed } 1 mark next n average = total/500 } 1 mark print average, highest, slowest } 1 mark

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This document consists of 17 printed pages and 3 blank pages.

IB10 06_7010_11/FP © UCLES 2010 [Turn over

*8454621681*

For Examiner's Use

UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS General Certificate of Education Ordinary Level

COMPUTER STUDIES 7010/11

Paper 1 May/June 2010

2 hours 30 minutes

Candidates answer on the Question Paper.

No Additional Materials are required.

READ THESE INSTRUCTIONS FIRST

Write your Centre number, candidate number and name on all the work you hand in.

Write in dark blue or black pen.

You may use a soft pencil for any diagrams, graphs or rough working.

Do not use staples, paper clips, highlighters, glue or correction fluid.

DO NOT WRITE IN ANY BARCODES.

Answer all questions.

No marks will be awarded for using brand names of software packages or hardware.

At the end of the examination, fasten all your work securely together.

The number of marks is given in brackets [ ] at the end of each question or part question.

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© UCLES 2010 7010/11/M/J/10

For

Examiner's

Use

1 Explain, with examples, the following five computer terms:

(a) Video conferencing

[2]

(b) Simulation

[2]

(c) Interrupt

[2]

(d) Batch processing

[2]

(e) Expert system

[2]

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3 You have been asked to produce a presentation on the social impact of computers on shop workers.

(a) What software features would you use to make your presentation interesting?

[2]

(b) What could you include in your presentation to show how the workers would be

affected?

[2]

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© UCLES 2010 7010/11/M/J/10

For

Examiner's

Use

4 A company is concerned about three aspects of the security of data stored in computer files:

• data corruption • data loss • illegal access to data

For each of the above, give one reason why it could occur and state one method of prevention. Your reasons must be different in each case. Data corruption Reason:

Data corruption Prevention:

Data loss Reason:

Data loss Prevention:

Illegal access to data Reason:

Illegal access to data Prevention:

[6]

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© UCLES 2010 7010/11/M/J/10

For

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Use

6 (a) Give three different types of device that allow human beings to interface with computer systems.

1

2

3

[3]

(b) Give three automatic data capture devices and give a suitable application for each

device.

Device 1

Application 1

Device 2

Application 2

Device 3

Application 3

[6]

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7 Describe how a supermarket would use computer technology to carry out automatic stock control.

[3]

8 (a) Describe the term virtual reality. Include examples of the special hardware needed to

react with virtual reality systems in your answer.

[3]

(b) Give two advantages of using virtual reality systems.

1

2

[2]

(c) Give one example of an application that uses virtual reality.

[1]

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© UCLES 2010 7010/11/M/J/10

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Use

9 Many software applications use drop-down menus. (a) What is meant by the term drop-down menu?

[2]

(b) A user is filling out an order form on the Internet. (i) Give one example where a drop-down menu could help the user.

(ii) Give one example where a drop-down menu should not be used to help the user.

[2]

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10 (a) Compilers and interpreters translate high-level languages. Give two differences between compilers and interpreters.

1

2

[2]

(b) Programs can be written using high-level or low-level languages. Give one advantage of using each method.

High-level language advantage

Low-level language advantage

[2]

(c) What is meant by top-down design when developing new software?

[1]

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0

© UCLES 2010 7010/11/M/J/10

For

Examiner's

Use

11 A student set up a spreadsheet to compare share prices in six companies over five years.

(a) What formula is in cell G5 to find the average (mean) share price for KLN?

[1]

(b) What formula is in cell H5 to find the highest share price for KLN?

[1]

(c) If the data in cell E4 was changed to 425, which cells would be automatically updated?

[1]

(d) The student wants to extend the spreadsheet to include share prices for 2010.

Describe how the student would do this.

[2]

A B C D E F G H 1

Name of company

Share price

Share price

Share price

Share price

Share price

Average share price

Highest share price

2 Year: 2005 2006 2007 2008 2009 3 Global Oil 81 190 305 130 140 169 305 4 GSD 619 722 622 325 324 522 722 5 KLN 60 71 71 63 45 62 71 6 Nesto 316 418 522 600 640 499 640 7 Takkco 149 316 394 202 122 237 394 8 Uniway 122 135 254 365 570 289 570

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12 A golf course charges $10 for each game of two people. Each additional person incurs a further charge of $2 per game. If they book two or more games in advance, they get a 10% discount on the total charge.

The following program has been written in pseudocode to calculate the charges for a game.

1 extracost = 0 2 input numberpeople, numbergames 3 charge = 10 * numbergames 4 extrapeople = numberpeople – 2 5 if numberpeople < 2 then extracost = 2 * extrapeople * numbergames 6 charge = extracost 7 if numbergames > 1 then charge = charge * 0.1 8 print charge

There are three errors in the program. Locate these errors and suggest a correct piece of

coding.

Error 1

Correction 1

Error 2

Correction 2

Error 3

Correction 3

[6]

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2

© UCLES 2010 7010/11/M/J/10

For

Examiner's

Use

13 Networks can have ring, bus or star topology. (a) Draw and name a diagram to show two of these networks.

Network 1 Network 2 Name: ……………………………. Name: ……………………………. [2] (b) Give one advantage of each chosen network.

Advantage network 1

Advantage network 2

[2]

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For

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14 A shower unit is controlled by sensors and a microprocessor.

sensors

hot water out

cold water in

water valve

water heater

microprocessor

(a) Describe how the sensors and microprocessor are used to ensure the correct water flow and water temperature are maintained.

[4]

(b) Give one safety feature that could be built into the shower unit in case the sensors

and/or microprocessor fail.

[1]

(c) What is the advantage of having microprocessor control rather than manual control of

water flow and temperature?

[1]

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4

© UCLES 2010 7010/11/M/J/10

For

Examiner's

Use

15 A database has been set up to bring together information about the world’s tallest buildings. A section of the database is shown below.

Ref No.

Building Name City Country Year No. of Floors

Height (m)

Height (ft)

TA1 Taipei 101 Taipei Taiwan 2004 101 508 1667 MA1 Petronas Towers Kuala Lumpur Malaysia 1998 88 452 1483 US1 Sears Tower Chicago USA 1974 110 442 1451 CH1 Jiu Mao Building Shanghai China 1999 88 421 1381 CH2 Finance Centre Hong Kong China 2003 88 415 1362 CH3 CITIC Plaza Guangzhan China 1996 80 391 1283 CH4 Shun Hing Square Shenzhen China 1996 69 384 1260 US2 Empire State Building New York USA 1931 102 381 1250 CH5 Central Plaza Hong Kong China 1992 78 374 1227 CH6 Bank of China Hong Kong China 1989 70 367 1205 DU1 Emirates Tower Dubai Dubai 1999 54 355 1165 TA2 Tuntex Sky Tower Kaohsiung Taiwan 1997 85 348 1140

(a) How many records are in the section of the database shown?

[1]

(b) Using Ref No. only, which records would be output if the following search condition was

entered: (Year < 1990) AND (Height (m) > 375)?

[1]

(c) Write down a search condition to find out how many buildings are in China or how many

buildings have more than 80 floors.

[2]

(d) For each of the following fields give a different validation check.

Year

Ref No.

[2]

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(e) The database was sorted in descending order of Year. Using Ref No. only, write down the results of the sort.

[1]

16 A company has set up an Internet website to sell their electrical goods online. (a) Give two features you would expect to see on the website.

1

2

[2]

(b) Payments for goods can be made by credit/debit cards. Data from the cards is

encrypted. (i) What is encryption?

(ii) Why is data encrypted?

[2]

(c) Apart from credit card fraud, people have other fears about buying from the Internet.

Describe one of these fears.

[1]

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© UCLES 2010 7010/11/M/J/10

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17 (a) Two methods of connecting to the Internet are dial-up and broadband. Give two advantages of using broadband.

1

2

[2]

(b) Computers often use wireless (WiFi) technology to connect to the Internet. Give one

advantage and one disadvantage of using WiFi.

Advantage

Disadvantage

[2]

(c) Apart from computers, name another device that uses WiFi technology.

[1]

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© UCLES 2010 7010/11/M/J/10

For

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18 A group of students were monitoring the temperature every day over a one-year period. Readings were taken ten times every day (you may assume a year contains 365 days).

Write an algorithm, using pseudocode or flowchart, which

• inputs all the temperatures (ten per day) • outputs the highest temperature taken over the year • outputs the lowest temperature taken over the year • outputs the average temperature per day • outputs the average temperature for the whole year

[7]

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UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS

GCE Ordinary Level

MARK SCHEME for the May/June 2010 question paper

for the guidance of teachers

7010 COMPUTER STUDIES

7010/11 Paper 11, maximum raw mark 100

This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the details of the discussions that took place at an Examiners’ meeting before marking began, which would have considered the acceptability of alternative answers.

Mark schemes must be read in conjunction with the question papers and the report on the examination.

• CIE will not enter into discussions or correspondence in connection with these mark schemes. CIE is publishing the mark schemes for the May/June 2010 question papers for most IGCSE, GCE Advanced Level and Advanced Subsidiary Level syllabuses and some Ordinary Level syllabuses.

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GCE O LEVEL – May/June 2010 7010 11

© UCLES 2010

1 (a) video conferencing Any two points from: – meeting between 2 or more participants – using computer networks/Internet – to transmit audio/video data in real time – pictures appear in a window on a monitor in real time – reference to hardware (webcams, speakers, microphones) – reference to software (communications, compression) [2] (b) simulation Any two points from: – studying the behaviour of a system – by using a model/mathematical representation – results can be predicted – e.g. flight (or other) simulator, modelling hazardous chemical processes – e.g. 10-pin bowling computer game [2] (c) interrupt Any two points from: – a signal/request generated by a device/program – which causes a break in the execution of a program/stops the program – e.g. printer out of paper, key pressed, disk full [2] (d) batch processing Any two points from: – processing doesn’t start until all data is collected – JCL (any reference to Job Control Language) – no need for user interaction – processed all in one go – done at “quiet” times – output not time sensitive – e.g. billing, payroll, cheque processing [2] (e) expert system Any two points from:

– computer system that emulates/simulates human knowledge/contains knowledge of human expert

– uses an inference engine – contains a knowledge base – made up of rule base – reference to expert system shell – outputs probability of diagnosis given being correct/produces reasoned conclusions – uses “Yes/No”, multichoice interface – e.g. medical diagnosis, chess, prospecting, financial modelling, diagnostics [2]

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© UCLES 2010

2 Any two tasks from: – design data collection forms – design input forms/user interface – design systems flowcharts – design output forms/reports/screens – design/select validation rules – design/select verification methods – design test plan/strategy – specify/select hardware – specify/select software – design algorithms/program flowcharts/pseudocode – specify data structures – design files (structures)/tables / layout – design queries [2] 3 (a) Any two features from: – sound and/or video clips embedded in the presentation/multimedia – animation effects – diagrams/graphs/charts (in colour)/colour/text fonts etc – hyperlinks [2] (b) Any two from: – how it affects tasks such as filing/ordering etc. – retraining aspects – deskilling aspects – unemployment [2] 4 Any three different reasons and associated preventions (prevention must match reason): 1 mark for reason, 1 mark for prevention award each point only once data corruption and data loss viruses -use anti virus software, firewalls, no Internet access power loss – back-ups, UPS malicious damage – back-ups, password protection, controlled access computer crash – back-ups, parallel computer (systems) damage to CDs/disks – back-ups operator error – training / good user interfaces illegal access hacking/unauthorised access – passwords, log-in ids, anti-hacking software (physical) lock room/computer computer left logged on – log off when not in use, lock computer [6]

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© UCLES 2010

5 1 mark per description, 1 mark per advantage, 1 mark per disadvantage Direct – old system stopped and next day new system started Advantage: – benefits are immediate/less time wasted – reduced costs (only one system so fewer staff) – less likely to malfunction since fully tested Disadvantage: – disastrous if new system fails/no fall back option Parallel – old system and new system are run together for a time Advantage: – if new system goes down, have old system as back up – can gradually train staff/have time to get used to new system Disadvantage: – more expensive/time consuming since 2 systems run together Pilot – new system introduced into only part of the company Advantage: – if new system fails, only that part affected (rest is alright) – can gradually train staff/have time to get used to new system Disadvantage: – time consuming (waiting to see how new system works) Phased – part of the new system introduced and when it proves to work another part is

introduced, etc./introduced part by part Advantage: – only a small part of the operations is affected if new system fails – no need to pay two sets of wages (so cheaper) – can ensure system works properly before expanding Disadvantage: – time consuming (each part needs to be tested before expanding) [6] 6 (a) Any three from: – keyboard (type in the responses) – touch screen (select options from on screen menus) – mouse/trackerball/touchpad (click on options from a menu) – microphone (speak options) – data gloves/goggles – camera [3]

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© UCLES 2010

(b) Any three different devices + associated application areas, e.g.: – bar code reader – stock control – library systems – OMR/mark sensing – multi-choice papers – questionnaires – touch screens – information desks/kiosks – choosing goods on line – sensors – monitoring chemical plant – central heating systems – cameras – traffic control – security – MICR – reading bank cheques – reading travellers cheques – microphones – telephone systems – games – magnetic stripe reader – reading credit cards – reading security cards – data loggers – weather monitoring – collecting experimental data – OCR – reading in documents Scanner – scanning in photos etc. [6]

7 Any of the following three stages: – each time item is bought, bar code scanned (at POS)/use of bar codes – bar code searched for on database/file – number in stock reduced by 1 – when stock level < re-order level/minimum level …… – …… automatic re-ordering carried out – when new stock arrives, stock levels updated [3]

8 (a) Any three from: – 3D visual world – created by a computer – form of computer simulation – data gloves used – data goggles/headsets used – hardware/motors to provide movement – special suits fitted with sensors [3]

(b) Any two from: – safety (e.g. can “view” inside a nuclear reactor) – feeling of “being there” – can perform “actual tasks” beforehand (without risk) – less expensive (IF QUALIFIED!!) [2]

(c) Any one from e.g.: – (medical) training – walk throughs (e.g. virtual tours of a house) – simulators (e.g. flight) – 3D arcade games – investigating problems in nuclear/chemical plants [1]

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© UCLES 2010

9 (a) Any two points from: – e.g. choose by clicking on an arrow – limited number of options available – highlights option chosen – use of pointing device to select an option [2] (b) (i) Any one from: – used where limited number of options exist – e.g. names of countries, days of month, date of birth (ii) Any one from: – cannot be used where “infinite” number of options exist – e.g. addresses, people’s names [2] 10 (a) Any two differences from: compiler interpreter – needs to be re-compiled every – translates instructions one time a change is made at a time …. – code can be executed on its own – then executes the instructions immediately – translates whole code in one go – only finds errors as each instruction executed – translates source code into – easier to edit/debug object code/machine code – produces error list at end of compilation [2] (b) Any one high level advantage and any one low level advantage: high-level language – fewer instructions – no need to understand registers/computer architecture – instructions nearer to human language/English – not machine specific/portable – easier to debug programs – easier to write programs low-level language – gain knowledge of how a computer works – more control over how registers (etc.) are accessed – can access registers (etc.) directly [2] (c) Any one from: – program/algorithm broken down into simpler modules/smaller tasks – each module is further sub-divided until basic elements produced – allows several programmers to work at same time on the software – can test each module independently [1]

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© UCLES 2010

11 (a) = AVERAGE(B5:F5) or = AVERAGE(B5,C5,D5,E5,F5) or = SUM(B5:F5)/5 or = (B5+C5+D5+E5+F5)/5 [1] (b) = MAX(B5:F5) or = MAX(B5,C5,D5,E5,F5) [1] (c) G4, (H4) [1] (d) – add column between F and G/insert column before G/insert column after F – change the formula(s) to allow 2010 data to be added [2] 12 1 mark for each error identified + 1 mark for each suggested correction – error line 5: numberpeople < 2 is incorrect correction: numberpeople > 2 – error line 6: the formula/charge = extracost is incorrect correction: charge = extracost + charge – error line 7: discount calculation/charge = charge * 0.1 is incorrect, correction: charge = charge * 0.9 [6]

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© UCLES 2010

13 (a) Any two from:

Ring star bus [2]

(b) One mark per advantage given:

Ring – can create much larger networks – faster/better operation under heavy workload – requires less cabling than a STAR network, for example

Star – easy to install and wire/expand – no disruptions to network if terminal fails – easy to detect faults in the system – central monitoring and network management possible

Bus – failure of single terminal doesn’t affect entire network – easy to connect a new terminal to the network – requires less cabling, therefore less expensive than others [2]

14 (a) Any four points from: – flow sensor / temperature sensor …. – …… send information / signal / data to microprocessor – ADC converts data/signal (for microprocessor to understand/process) – microprocessor compares flow rate/temperature with pre-set values – sends signal to valve/heater to control flow rate/temp as required – use of a DAC interface – use of actuators – system loops continuously until switched off [4]

(b) Any one from: – fail safe/switches off automatically – temperature automatically sets to cold/switches off the heating – flow cuts off and temperature sets to cold

(NOT a warning light/buzzer comes on) [1]

(c) Any one from: – more accurate control – safer system – more energy efficient [1]

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© UCLES 2010

{

{

15 (a) 12 [1] (b) US1,US2 [1] (c) (Country = “China”) OR (No. of Floors > 80) ←------1 mark ----→ ←-------- 1 mark --------→ (No. of Floors > 80) OR (Country = “China”) ←------1 mark ----→ ←-------- 1 mark --------→ [2] (d) (i) range check, character check, length check (ii) character check, type check, length check, format check [2] (e) TA1, CH2, CH1, DU1, MA1, TA2, CH3, CH4, CH5, CH6, US1, US2 (any order) (any order) [1] 16 (a) Any two from e.g.: – electronic checkout – shopping basket – ability to track status of order on line – secure buying using credit cards – “when customer bought X, they also bought Y” facility – search facilities for items – recognise customers as soon as they log on – drop down boxes to choose categories – sales confirmation by automatic email – save customer details/customised pages – online help facility – hyperlinks to other pages – ability to bookmark/tag page(s) [2] (b) (i) Any one from: – process of changing/scrambling/encoding data into a meaningless form – use of software/algorithms to turn data into a meaningless form [1] (ii) Any one from: – to avoid data being read/understood by hackers/unauthorised people – to protect sensitive data from unauthorised people [1] (c) Any one from: – viruses being downloaded from the site – bogus/fake sites – “unwanted sites”/porn sites coming up when searching – unsolicited mail – “cookies” (etc.) being stored on hard drive (spying software) – hacking [1]

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© UCLES 2010

17 (a) Any two advantages from: – always “on”/no need to dial into ISP – connection rate much higher (e.g. 11000 kbps cf 60 kbps) – flat monthly rate (dial up charges based on number of hours used) – can use phone line at same time/line not tied up – allows other facilities such as VoIP – download rate is much faster [2] (b) Any one advantage and any one disadvantage from: Advantages – can use anywhere within range – no trailing wires Disadvantages – range can be limited – possible interference from electronic devices – security/tapping into WiFi networks – (often) slower access speed than wired systems [2] (c) Any one from: e.g. – printers – keyboard – mouse – cameras – mobile phone – GPS [1]

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© UCLES 2010

18 Marking points (maximum of 7 marks) – initialising highest and lowest to reasonable values (must not be zero) – first loop controlling one year (365 days) – re-setting total for each day – second loop controlling readings taken per day – read temperature – calculate total day temperature – calculate total year temperature – identifying highest temperature – identifying lowest temperature – finding average temperature for day – finding average temperature for year – output average day temperature inside loop – output highest, lowest, average outside the loop Sample algorithm in pseudocode highest = -100: lowest = 100: total year = 0 } 1 mark for c = 1 to 365 } 1 mark total day = 0 } 1 mark for d = 1 to 10 } 1 mark read temp } 1 mark total day = total day + temp } mark total year = total year + temp } 1 mark if temp > highest then highest = temp } 1 mark if temp < lowest then lowest = temp } 1 mark next d average day = total day/10 } 1 mark print average day } 1 mark next c average year = total year/3650 } 1 mark print highest, lowest, average year } 1 mark [7]

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This document consists of 19 printed pages and 1 blank page.

IB10 06_7010_12/FP © UCLES 2010 [Turn over

*5409191667*

For Examiner's Use

UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS General Certificate of Education Ordinary Level

COMPUTER STUDIES 7010/12

Paper 1 May/June 2010

2 hours 30 minutes

Candidates answer on the Question Paper.

No Additional Materials are required.

READ THESE INSTRUCTIONS FIRST

Write your Centre number, candidate number and name on all the work you hand in.

Write in dark blue or black pen.

You may use a soft pencil for any diagrams, graphs or rough working.

Do not use staples, paper clips, highlighters, glue or correction fluid.

DO NOT WRITE IN ANY BARCODES.

Answer all questions.

No marks will be awarded for using brand names of software packages or hardware.

At the end of the examination, fasten all your work securely together.

The number of marks is given in brackets [ ] at the end of each question or part question.

..59

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© UCLES 2010 7010/12/M/J/10

For

Examiner's

Use

1 Explain, with examples where appropriate, the following five computer terms.

(a) buffer

[2]

(b) batch processing

[2]

(c) e-commerce

[2]

(d) simulation

[2]

(e) email

[2]

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For

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2 A company making televisions has introduced robots to replace the human work force. (a) Describe three effects this would have on the work force.

1

2

3

[3]

(b) Give two advantages to the company of introducing robots.

1

2

[2]

(c) How could the robots be trained to assemble the televisions?

[1]

(d) A whole batch of televisions was produced with some of the parts missing. How could

this error have been avoided?

[1]

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© UCLES 2010 7010/12/M/J/10

4 Give four features of a Data Protection Act.

1

2

3

4

[4]

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5 A bank is worried about computer crime. One of their concerns is online access to customer accounts. (a) How can a customer’s access details be discovered by criminals?

[2]

(b) Why would a customer using a credit card for online shopping be more of a security

risk than a customer using the same card in a shop?

[2]

(c) Describe what measures the bank can take to safeguard customer accounts.

[2]

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© UCLES 2010 7010/12/M/J/10

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Examiner's

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6 An expert system is being developed to help engineers diagnose faults in aero engines. (a) Describe the steps taken to develop this new expert system.

[4]

(b) Another method used to identify and rectify faults is to train engineers using

virtual reality systems. (i) What is virtual reality?

[1]

(ii) What special hardware is used to interface with virtual reality systems?

[1]

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7 A screen has been developed to allow the input of data into the following fields: name, sex, address, date of birth and examination results. (a) A first attempt at designing the screen is shown below:

This is not a very good input screen. Give four ways in which it could be improved.

1

2

3

4

[4]

(b) (i) What is verification?

(ii) Which fields should be verified?

[3]

Student Records

Student name: ………………………………….. Sex: ……………………

Student address: ………………………………………………………………

…………………………………………………………………………………….

Date of birth: ……… / ……… / ………

Exam results: Subjects and Grades

Type in NEXT to go to next student or BACK to go to previous

student: …………………………

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8 A supermarket makes use of barcodes on all its goods as part of its automatic stock control system.

(a) Describe how the price is found for each item sold.

[2]

(b) The following are steps in the automatic stock control system. Number the steps in the correct order.

if stock level ≤ minimum stock level

report printed out for the manager

stock level reduced by 1

new stock value written back to file

more items are ordered automatically

[4] 9 A factory uses a computer system to store information about customers, spare parts and

general administration. (a) Spare parts can be identified by selecting from diagrams on a computer screen. Describe what hardware would be needed to allow the parts to be selected in this way.

[2]

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(b) The factory needs to buy a new printer. It has decided to buy either a dot matrix printer or an inkjet printer. Discuss the advantages and disadvantages of using both types of printer in this application.

Dot matrix printer:

Advantages

Disadvantages

[3]

Inkjet printer:

Advantages

Disadvantages

[3]

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© UCLES 2010 7010/12/M/J/10

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10 A small company runs six cars in its fleet. They have produced a spreadsheet to compare running costs over a five month period:

(a) It was decided to print out the spreadsheet formulas from D2 to E8. Using the grid

below, show what formulas would be printed:

D E

1

Total cost ($)

Average cost per month ($)

2

3

4

5

6

7

8

[4]

A B C D E

1

Car Identity Total number of km

Cost per km ($)

Total cost ($)

Average cost per month ($)

2 10001 30 000 1.00 30 000 6 000

3 10002 20 000 4.00 80 000 16 000

4 10003 50 000 1.50 75 000 15 000

5 10004 30 000 2.00 60 000 12 000

6 10005 20 000 2.50 50 000 10 000

7 10006 30 000 1.50 45 000 9 000

8 Averages: 2.08 56 667 11 333

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(b) A graph of Cost per km ($) was drawn:

4.5

4

3.5

3

2.5

2

1.5

1

0.5

010001 10002 10003 10004

Car identity

Cost per km ($)

Cos

t per

km

($)

10005 10006

(i) Which cells were highlighted to produce this graph?

[2]

(ii) Describe how the average value of 2.08 would be shown on the graph.

[1]

(c) The data in cell C6 was changed to 3.00. Which cells would be updated automatically?

[2]

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© UCLES 2010 7010/12/M/J/10

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11 A database has been set up showing information about cars:

Car ref No of doors

Engine (litres)

CO2 (g/km)

Fuel used (km/litre)

No of cylinders

A 3 1.4 145 15.3 4

B 4 2.0 193 12.3 4

C 5 2.5 231 10.9 6

D 3 2.0 190 11.2 6

E 4 1.3 120 17.5 4

F 5 1.8 180 14.6 4

G 4 3.0 240 9.5 6

H 4 1.2 115 19.7 3

(a) Using Car ref only, write down which cars would be output if the following search

condition was used: (No of doors = 4) AND (Fuel used (km/litre) > 15)

[2]

(b) Write down a search condition to find out which cars have engines larger than 1.8 litres

OR have CO2 emissions higher than 150 g/km.

[2]

(c) The database is sorted in ascending order on Fuel used (km/litre). Using Car ref

only, write down the results of the sort.

[2]

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12 (a) State two items of hardware needed to enable a standard computer system to take part in video conferencing.

1

2

[2]

(b) State two additional items of software that would be needed for the video conferencing

to take place.

1

2

[2]

(c) Describe two potential problems when using video conferencing.

1

2

[2]

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© UCLES 2010 7010/12/M/J/10

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13 Study the following flowchart very carefully:

START

STOP

PRINT N

INPUT X

T = X

Is X = 0?

N = 1

T = T/10

Is T < 10?

N = N + 1

No

Yes

STOP

PRINT“error”

Yes

No

What output would you expect if the following data was input into the flowchart?

X OUTPUT

-150

540

0

[3]

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14 A safety system has been developed to stop vehicles getting too close to each other on the road.

A B

sensors

If vehicle A gets too close to vehicle B, the brakes are automatically applied by a computer system in vehicle A.

(a) What type of sensors could be used on the vehicles?

[1]

(b) Describe what the safety system does to constantly monitor how close the vehicle is to

the vehicles in front and decide when to take action.

[4]

(c) Describe two potential problems with this safety system.

1

2

[2]

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15 A floor turtle can use the following instructions:

Instruction Meaning

FORWARD d Move d cm forward

BACKWARD d Move d cm backward

LEFT t Turn left t degrees

RIGHT t Turn right t degrees

REPEAT n Repeat the next set of instructions n times

ENDREPEAT End of REPEAT loop

PENUP Raise the pen

PENDOWN Lower the pen

(In the following grid, each square is 10 cm by 10 cm.)

Start End

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Complete the set of instructions to draw the shape (shown in bold lines) by filling in the blank lines.

LEFT 90

PENDOWN

FORWARD 10

RIGHT 90

[5]

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16 (a) Write an algorithm, using pseudocode or a flowchart, which:

� inputs 50 numbers � outputs how many of the numbers were > 100

[3]

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(b) Write an algorithm, using pseudocode or a flowchart, which:

� inputs 100 numbers � finds the average of the input numbers � outputs the average

[3]

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UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS

GCE Ordinary Level

MARK SCHEME for the May/June 2010 question paper

for the guidance of teachers

7010 COMPUTER STUDIES

7010/12 Paper 12, maximum raw mark 100

This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the details of the discussions that took place at an Examiners’ meeting before marking began, which would have considered the acceptability of alternative answers.

Mark schemes must be read in conjunction with the question papers and the report on the examination.

• CIE will not enter into discussions or correspondence in connection with these mark schemes. CIE is publishing the mark schemes for the May/June 2010 question papers for most IGCSE, GCE Advanced Level and Advanced Subsidiary Level syllabuses and some Ordinary Level syllabuses.

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Mark Scheme: Teacher version Syllabus Paper GCE O LEVEL – May/June 2010 7010 12

© UCLES 2010

1 (a) buffer Any two points from: – temporary … – … storage/memory – compensates for the difference in speed of peripherals and CPU – e.g. printer (buffer) [2] (b) batch processing Any two points from: – processing doesn’t start until all data is collected – JCL (any reference to Job Control Language) – no need for user interaction – processed all in one go – done at “quiet” times – e.g. billing, payroll, cheque processing [2] (c) e–commerce Any two points from: – electronic commerce – buying and selling products/services ….. – ….. using the internet/computer networks – reference to B2B (business to business) or B2C (business to consumer/customer) – e.g. on-line shopping, commodity exchanges, Internet/online banking [2] (d) simulation Any two points from: – studying the behaviour of a system – by using a model/mathematical representation – results can be predicted – e.g. flight (or other) simulator, modelling hazardous chemical processes – e.g. 10-pin bowling computer game [2] (e) email Any two points from: – electronic mail – sending messages from one device to another using computer networks/Internet – world wide form of electronic communication – can send file attachments – e.g. sending a letter without use of traditional mail service [2]

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© UCLES 2010

2 (a) Any three points from: – loss of jobs/unemployment – deskilling – need to re-train – different jobs available/re-skilling – no longer need to do hazardous/tedious jobs [3] (b) Any two points from: – lower work force costs (no salaries to pay) – lower environmental costs (less electricity for heating/lighting) – higher throughput – more consistent product – robots don’t need breaks, holidays/work 24/7 etc. – robots don’t take industrial action [2] (c) Any one point from: – tasks repeated by skilled worker and how each task is done is memorised – tasks programmed directly into the computer/robot memory [1] (d) Any one point from: – if parts missing for a sequence, then a warning should be given and the assembly

stopped – several quality control stages to spot an error early on – program in checks at each stage of assembly so robots can detect a fault immediately [1] 3 Any four points from: – understand the current system – produce data flow diagrams/system flowchart – identify user/client requirements/objectives – interpret user/client requirements/objectives – agree requirements/objectives with the user/client – collect data from the current system – fact finding (e.g. questionnaires, interviewing, etc.) – problem identification [4] 4 Any four features from: – data must be up to date – data can only be read/used for the purpose for which it was collected – data must be adequate, relevant and not excessive – data must be accurate – data must be destroyed when no longer needed/don’t keep longer than necessary – data user must register what data stored – data must be used/collected fairly and lawfully – data must be held securely – data must be protected from accidental damage – only authorised personnel can have access to the data – fines are imposed for data mis-use – data should not be passed on to a third party without permission – a person can view data and have it changed/removed if incorrect – safe harbour (countries with DPA at least as good) [4]

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5 (a) 1 mark each for 2 concerns OR 1 mark for concern + 1 mark for expansion: – customer goes online in a public place ….. …… and is overlooked as they enter id/password/PIN – customer receives emails taking them to a false site ….. ….. where they are asked to confirm details by entering them – customer downloads virus, spyware, ….. ….. which logs all key presses including id/password/PIN [2] (b) Any two points from: – don’t need card number for online transaction/card number already – online user is anonymous/not visible – online the customer does not need the card and signature/PIN [2] (c) Any two points from: – secure sites using encryption – use of passwords/PINs/biometrics/advice to change PIN regularly – no communications with customer requiring personal details – use of home card readers that generate codes known only to bank and customer – check with customer at each log on when they were last logged on to the website – contact customer if unusual transaction/random check – customer asked to inform bank if intending to use card in another country – customer asked to inform bank if card lost/stolen – ensure firewall is in place [2] 6 (a) Any four points from e.g.: – gather information from experts/questionnaires – create the knowledge base – type/put information into computer – create rules/rules base – create/design inference engine – create/design input–output interface – fully test the system – expert system learns [4] (b) (i) Any one point from: – 3D visual world – uses computer simulation – uses special interface devices (e.g. data gloves and goggles) [1] (ii) Any one point from: – data gloves/goggles (if not given credit in part (i)) – hardware/motors to provide movement – special suits fitted with sensors [1]

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7 (a) Any four improvements from: – use (text) boxes for – names – addresses – sex – date of birth – subjects – grades – separate fields into separate entry items – name into first name and last name – address into street, city etc – drop down list/combo box for – date of birth – sex – subjects – grades – calendar object for – date of birth – radio buttons for – sex – hyperlinks for – NEXT – BACK [4] (b) (i) any one point from: – check on input for errors by double entry – on screen checking – check input is same as source (ii) – name

– address [3] 8 (a) Any two points from: – barcode is scanned/keyed in – barcode is validated (by check digit) – system looks up barcode in computer files/database – retrieves (and returns) price [2] (b)

if stock level < minimum stock level 3 report printed out for manager 5 stock level reduced by 1 1 new stock value written back to file 2 more items are ordered automatically 4

1 mark for each correct answer up to max of 4. 4 marks for all 5 correct 3 marks for any 3 or 4 correct 2 marks for any 2 correct 1 mark for any 1 correct [4]

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© UCLES 2010

9 (a) Any two correct input devices OR input device + correct type of screen – mouse/trackerball + CRT screen/TFT screen – touch screen + CRT screen/TFT screen – light pen + CRT screen [2] (b) Dot matrix printer: Accept a max of 2 advantages and a max of 2 disadvantages: Advantages: – suitable for dirty/dusty/damp atmospheres – cheap to maintain – cheap to run – can operate with continuous/multipart stationery Disadvantages: – poor print quality – very noisy – very limited colours [3] Inkjet printer: Accept a max of 2 advantages and a max of 2 disadvantages: Advantages: – inexpensive to purchase – high quality printouts – can use colours – supported by most operating systems – quiet Disadvantages: – run out of printing ink quickly/cartridges run out quickly – price per page/inks are expensive – not suitable for dirty/dusty/damp atmospheres [3]

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10 (a) Award marks as shown (each block = 1 mark):

D E

1 Total cost

($) Average cost per month ($)

2

= B2 * C2

= D2 / 5

3

= B3 * C3

= D3 / 5

4

= B4 * C4

= D4 / 5

5

= B5 * C5

= D5 / 5

6

= B6 * C6

= D6 / 5

7

= B7 * C7

= D7 / 5

8

= AVERAGE (D2 : D7)

Alternative answers:

= SUM(D2:D7)/6

= (D2+D3+D4+D5+D6+D7)/6

= AVERAGE (E2 : E7)

Alternative answers:

= SUM(E2:E7)/6

= (E2+E3+E4+E5+E6+E7)/6

= D8/5

[4] (b) (i) (A1 : A7) and (C1 : C7) (1 mark) (1 mark) [2] (ii) Any one point from: – add an extra column and set all values to 2.08 – draw a line at value 2.08 on the graph – add a trend/average line using spreadsheet software [1] (c) D6, E6, C8, D8, E8 (-1 mark for each error or omission) [2] 11 (a) E, H [2] (b) (Engine (litres) > 1.8) OR (CO2 (g/km) > 150) ← (1 mark) → ← (1 mark) → Or (CO2 (g/km) > 150) OR (Engine (litres) > 1.8) ← (1 mark) → ← (1 mark) → [2] (c) G, C, D, B, F, A, E, H (1 mark for correct order (fuel used) 1 mark for ascending order) [2]

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