A school network has several computers. Each computer in the network has a media access control (MAC) address. Hexadecimal is used for MAC addresses. Part of a MAC address is given. 97-5C-E1 Each pair of digits is stored as binary in an 8-bit register. (a) Complete the binary register for these two pairs of digits. (b) Describe what is meant by a MAC address. ] (c) Give two other uses of hexadecimal in computer science. (d) Another value is stored as binary in a register. 0 1 0 1 0 0 1 0 (i) A logical left shift of two places is performed on the binary value. Complete the binary register to show its contents after this logical left shift. [1] (ii) State one effect this logical shift has on the binary value. (e) Negative denary numbers can also be represented as binary using two's complement. Complete the binary register for the denary value 54. You must show all your working. Working space Register: [2] 2 A company has a website that is stored on a web server. (a) The website data is broken down into packets to be transmitted to a user. Describe the structure of a data packet. (b) The website hosts videos that users can stream. The company uploads new videos to the website. (i) The videos are compressed before they are uploaded to the website. Tick () one box to show which statement is a benefit of compressing the videos. A Data is encrypted. B Duration of each video will be reduced. C Less storage space on the web server is required. D More bandwidth is required when viewing the videos. [1] (ii) Give two methods of compression that could be used to compress the videos. (iii) The company uses parallel half-duplex data transmission to transmit the data for the new videos to the web server. Explain why parallel half-duplex data transmission is the most appropriate method. (c) The company is concerned about a distributed denial of service (DDoS) attack. (i) Describe what is meant by a DDoS attack. (ii) Suggest one security device that can be used to help prevent a DDoS attack. 3 (a) A web server has an internet protocol (IP) address. (i) Give three characteristics of an IP address. (ii) Identify the network component that uses the IP address to send data only to its correct destination. . (b) The website has a uniform resource locator (URL). An example of a URL is given. https://www.cambridgeassessment.org.uk/index.html Complete the table to identify the name of each section of the URL. URL section Name https cambridgeassessment.org.uk /index.html [3] 4 A computer has a Von Neumann architechure. (a) Circle three components that are part of the central processing unit (CPU) in this computer. accumulator (ACC) hard disk drive (HDD) memory address register (MAR) program counter (PC) random access memory (RAM) read only memory (ROM) sensor sold state drive (SSD) [3] (b) Describe the purpose of the control unit (CU) within this computer. (c) The computer has a single core CPU. (i) State one purpose of a core in a CPU. . (ii) The computer is upgraded to a dual core CPU. Explain how the upgrade can affect the performance of the computer. (d) The computer uses a bootstrap. Tick () one box to show the part of a computer of which the bootstrap is an example. A application software B firmware C hard disk drive D MAC address [1] 5 A programmer uses a high-level language to create a computer program. (a) (i) Identify two advantages to the programmer of using a high-level language instead of a low-level language. (ii) Suggest one disadvantage to the programmer of using a high-level language instead of a low-level language. (b) The programmer uses an integrated development environment (IDE) when creating the computer program. State what is meant by an IDE. 6 Robots are used in a factory to build cars. (a) One characteristic of a robot is its mechanical structure. State two other characteristics of a robot. ] (b) Suggest two advantages of using robots, instead of humans, to build cars in the factory. 7 The Unicode character set is used to represent text that is typed into a computer. (a) Describe what is meant by a character set. . (b) One disadvantage of using the Unicode character set, instead of the ASCII character set, is that the text stored takes up more storage space. Give one reason why it takes up more storage space. 8 (a) Draw a diagram to represent how virtual memory is created and used. [4] (b) A student is using software to create 3D models. This process often requires the use of virtual memory. Explain why virtual memory is needed for this process. 

9 Complete the sentences about symmetric encryption. Use the terms from the list. Some of the terms in the list will not be used. You should only use a term once. algorithm cipher copied delete key plain private public standard stolen understood unreadable The data before encryption is known as .................................................. text. To scramble the data, an encryption .................................................., which is a type of .................................................., is used. The data after encryption is known as .................................................. text. Encryption prevents the data from being .................................................. by a hacker. [5] 10 An art gallery uses secure socket layer (SSL) to provide a secure connection when selling art on its website. Describe the process of SSL and explain how it provides a secure connection.

11.The 1D array StudentName[] contains the names of students in a class. The 2D array StudentMark[] contains the mark for each subject, for each student. The position of each student's data in the two arrays is the same, for example, the student in position 10 in StudentName[] and StudentMark[] is the same. The variable ClassSize contains the number of students in the class. The variable SubjectNo contains the number of subjects studied. All students study the same number of subjects. The arrays and variables have already been set up and the data stored. Students are awarded a grade based on their average mark. Average mark Grade awarded greater than or equal to 70 distinction greater than or equal to 55 and less than 70 merit greater than or equal to 40 and less than 55 pass less than 40 fail Write a program that meets the following requirements: calculates the combined total mark for each student for all their subjects calculates the average mark for each student for all their subjects, rounded to the nearest whole number outputs for each student: - name - combined total mark - average mark - grade awarded calculates, stores and outputs the number of distinctions, merits, passes and fails for the whole class. You must use pseudocode or program code and add comments to explain how your code works. You do not need to initialise the data in the array.