1 mark each: X = Q AND (NOT P OR R) Y = S XOR (Q NOR R)

1 mark each to max 4 • Video is transmitted continuously • as a series of bits • The video is uploaded to a media server • The users download from the media server • On download, the media server sends the data to a buffer on the user's device • buffer is used when there is a difference in speed between transmission and receipt • Buffer stores data from server until recipient can receive it • Recipient views bit stream from the buffer

1 mark for each correct answer Statement Answer The term for the smallest element that makes up an image. pixel The largest number of different colours that can be represented with a bit depth of 8 bits. 256 // 28 The term for the dots per inch (dpi) when an image is displayed. Screen resolution

1 mark each to max 4 e.g. • Uses image recognition / facial recognition • Measures the distance between facial features of the customer • and stores the values in a database of user information • An image is captured using the digital camera • the AI identifies that the image is a face • by analysing the pixels to find patterns • the distance between features is calculated and compared to those in database

1 mark for each relationship. Max 2 if any extra

1 mark each • Selecting the customer ID, customer name and sum of TotalCost with appropriate identifier • FROM clause with suitable join of tables (ON or WHERE) • ORDER.Paid = FALSE condition (with correct key word) • GROUP BY condition e.g. SELECT CUSTOMER.CustomerID, CUSTOMER.Name, Sum(ORDER.TotalCost) AS TotalOwed FROM CUSTOMER INNER JOIN ORDER ON CUSTOMER.CustomerID = ORDER.CustomerID WHERE ORDER.Paid = FALSE GROUP BY CUSTOMER.CustomerID; Alternative JOIN Statement SELECT CUSTOMER.CustomerID, CUSTOMER.Name, Sum(ORDER.TotalCost) AS TotalOwed FROM CUSTOMER,ORDER WHERE CUSTOMER.CustomerID = ORDER.CustomerID AND ORDER.Paid = FALSE GROUP BY CUSTOMER.CustomerID;

1 mark for each correctly completed space • platters • spindle • read/write head • magnetic field The magnetic hard disk has one or more platters that can be magnetised. These are mounted on a spindle and rotate at high speed. A read/write head is moved across the surface on an arm. When data is read the changes in the magnetic field produce a change in the electric current.

1 mark for a correct method: 1 mark each to max 2 for a corresponding description Method: Encryption Description: • Data is encoded/scrambled using a key to create cipher text • if intercepted it cannot be understood • without being decrypted using a key

1 mark for each shaded section Instruction address ACC Memory address 81 83

2 1(b) 1 mark for first 4 rows, 1 mark for second 4 rows A B C Working space X 0 1 0 1 1 0 1 1 0 0 0 0 1 1 1 1 2

2 3(b)(ii) 1 mark for: 10,094 3(b)(iii) 1 mark for: 8,512 1

2 5(d) 1 mark each to max 3 e.g. • Each order would only be able to have one item • or the database would not be normalised • it would not be in 1NF • due to repeated groups of attributes • in the ORDER table 3

2 6(b) 1 mark each to max 5 e.g. • To provide a user interface • so that the user is able to communicate with the hardware • To manage memory • so that data can be stored and accessed • and multitasking is possible • To manage files • allowing the user to create, edit, update and delete files and folders • To manage inputs and outputs from hardware/peripherals • To handle processes • to make sure each process has fair access

3 2(c) 1 mark each modems: • Converts digital data into analogue for transmission down phone lines // Converts analogue data into digital after transmission down phone lines dedicated lines: • Used to provide a direct / private connection which therefore provides faster transmission

3 3(b)(i) 1 mark each to max 2 • A wider range of characters can be represented • so characters from more languages can be represented • and symbols such as emojis can be used

3 5(b) 1 mark for: CardNumber 5(c) 1 mark per row to max 2 Table Foreign key ORDER_ITEM OrderID ORDER CustomerID CUSTOMER_CARD_DATA CustomerID

3 6(a)(iii) 1 mark each to max 2 e.g. • Wider data bus means more data can be transferred between components at a time • there is less delay / latency when fetching data for a running process • Wider address bus means larger memory addresses can be used • allowing more memory locations to be accessed directly • so less likely to run out of memory

3 7(b) 1 mark each to max 5 • The sender hashes the document / message • to produce a digest • The sender encrypts the digest to create the digital signature • The message and the signature are sent to the banker / receiver • The receiver decrypts the signature to reproduce the digest • The receiver uses the same hashing algorithm on the document received to produce a second digest • The receiver compares this digest with the one from the digital signature • If both of the receiver’s digests are the same the document has not changed

4 2(b)(i) 1 mark each to max 4 e.g. • Video is data-intensive • The file size needs reducing in order to • reduce the amount of bandwidth used • and reduce buffering • This means people are not behind in the conversation • and people with lower bandwidth can still take part 2(b)(ii) No mark for choice but lossy is most appropriate 1 mark each to max 3 e.g. • Reduces file size more than lossless • so significantly less bandwidth / data is needed • so buffering is reduced even more than with lossless • Data can be removed which cannot be seen • reducing quality without impacting experience • for example, because resolution of video can be reduced // sample rate of audio can be reduced

4 4(b) 1 mark for sensor, 1 mark for corresponding use e.g. Sensor Use Pressure Detects when the pressure of an item is removed from a shelf / put back on a shelf Infrared Detects when the beam is broken for an item removed / added

4 6(a)(ii) 1 mark each to max 3 • More RAM means more currently running data and instructions can be stored • without needing to use virtual memory • without having to fetch the data from secondary storage first • which has a slower access time • Less latency / delay waiting for instructions / data

4 8(b)(i) 1 mark for: OR B0000 0001 // OR #1 // OR &1 8(b)(ii) 1 mark for: 1010 1011 8(b)(iii) 1 mark for: 0000 0011 1

5 7(c) 1 mark each to max 3 • The data is put through an algorithm to create a checksum value • The data and checksum are sent to the receiver • The receiver performs the same algorithm on the data • if both checksums match the data is verified 3

8 81 8 201

9 9 10 206 207

19 210 19