OCR Computer Science Trial Exam 2024 Nov PDF

Computer Science (J277) Trial Exam 2024 Nov, Computer systems, June 2024_clone Shahnaz Qanungo Please note that you may see slight differences between this paper and the original....

Computer Science (J277) Trial Exam 2024 Nov, Computer systems, June 2024_clone Shahnaz Qanungo Please note that you may see slight differences between this paper and the original. Duration: 80 mins Candidates answer on the Question paper. OCR supplied materials: Additional resources may be supplied with this paper. Other materials required: Pencil Ruler (cm/mm) Candidate Candidate forename surname Centre number Candidate number INSTRUCTIONS TO CANDIDATES Write your name, centre number and candidate number in the boxes above. Please write clearly and in capital letters. Use black ink. HB pencil may be used for graphs and diagrams only. Answer all the questions, unless your teacher tells you otherwise. Read each question carefully. Make sure you know what you have to do before starting your answer. Where space is provided below the question, please write your answer there. You may use additional paper, or a specific Answer sheet if one is provided, but you must clearly show your candidate number, centre number and question number(s). INFORMATION FOR CANDIDATES The quality of written communication is assessed in questions marked with either a pencil or an asterisk. In History and Geography a Quality of extended response question is marked with an asterisk, while a pencil is used for questions in which Spelling, punctuation and grammar and the use of specialist terminology is assessed. The number of marks is given in brackets [ ] at the end of each question or part question. The total number of marks for this paper is 80. The total number of marks may take into account some 'either/or' question choices. © OCR 2024. You may photocopy this page. 1 of 15 Created in ExamBuilder  1(a) The following table has either the binary or denary value of 3 numbers. Complete the table by converting the 8-bit binary number into denary and the denary number into 8-bit binary. 8-bit Binary Denary 11110000 105 00011110 (b) Complete the table by writing the answer to each statement. Statement Answer The smallest denary number that can be represented by a 4-bit binary number The largest denary number that can be represented by a 6-bit binary number The maximum number of different colours that can be represented with a colour depth of 7-bits The minimum number of bits needed to represent 150 different characters in a character set (c) Show the result of a left binary shift of 4 places on the binary number 00001111. © OCR 2024. You may photocopy this page. 2 of 15 Created in ExamBuilder  (d) Describe how to convert a 2-digit hexadecimal number into denary. Use an example in your answer. (e) Add these two 8-bit binary numbers using binary addition. Show your working out. © OCR 2024. You may photocopy this page. 3 of 15 Created in ExamBuilder  2(a) An airport has computers that are connected together on a Local Area Network (LAN). The airport currently has wired connections in their Local Area Network. (i) Describe two benefits to the airport of using wired connections in their network. 1 2 (ii) Explain the reasons why the airport should also allow the network to be accessed using a wireless connection. © OCR 2024. You may photocopy this page. 4 of 15 Created in ExamBuilder  (b) One office in the airport has five computers connected to one switch. There are two printers in the office that can be accessed by all computers. The computers are connected using a star topology. (i) Draw a diagram to show how the five computers, switch and two printers are connected in a star topology. (ii) Give one benefit and one drawback of the office using a star topology instead of a mesh topology. Benefit Drawback (iii) Describe the role of the switch in the star topology. © OCR 2024. You may photocopy this page. 5 of 15 Created in ExamBuilder  3(a) The table contains operating system functions and a task that each function performs. Complete the table by writing the two missing function names and a task performed by the two given functions. Function Task Moves data from secondary storage to RAM Peripheral management Allows the user to create, name and delete folders User interface © OCR 2024. You may photocopy this page. 6 of 15 Created in ExamBuilder  (b) Complete the description of utility system software using the words provided in the box. Not all words are used. access amount apart compression consecutive defragmentation deleted encryption key lock quantity separate speed understood................................................ software changes data using a................................................ If the changed data is intercepted, it cannot be................................................ This software does not stop the data from being intercepted................................................. software analyses the data on a disk to find files that have been split and stored in separate locations. The split files are moved to be................................................ in storage and the free space is moved together. This does not provide more storage space on the disk, instead it makes the................................................ of the data faster because the read head does not have to move as far to access the next part of the file. © OCR 2024. You may photocopy this page. 7 of 15 Created in ExamBuilder  4(a) A musician uses a computer to make and record music. (i) Tick (✓) one box to identify the correct description of sound sampling. The frequency of the wave is measured a set number of times each second. The amplitude of the wave is measured at set intervals. The digital sound wave is measured a set number of times each second. The analogue sound wave’s resolution is measured at set intervals. (ii) Explain how changing the bit depth will affect the sound file. © OCR 2024. You may photocopy this page. 8 of 15 Created in ExamBuilder  (b) The musician has run out of storage space on their secondary storage device and needs to buy a replacement. (i) Identify whether the musician should buy a magnetic secondary storage device or a solid state secondary storage device for their computer. Justify your choice. Type Justification (ii) Identify one other type of secondary storage. (iii) Tick (✓) one box to identify the smallest secondary storage capacity. 2.1 GB 300 MB 200 000 KB 0.0021 TB © OCR 2024. You may photocopy this page. 9 of 15 Created in ExamBuilder  (iv) The musician’s recordings have an average (mean) file size of 3 MB. The musician has 1000 recordings. Calculate an estimate of the storage space in GB that the 1000 files will require, assuming they are each 3 MB in size. Show your working out. Working space: Answer:......................................... GB 5(a) A computer has a Central Processing Unit (CPU). Describe what happens during the fetch-execute cycle. © OCR 2024. You may photocopy this page. 10 of 15 Created in ExamBuilder  (b) Complete the table by writing the name of two registers used in the fetch-execute cycle and the purpose of each register. Register Purpose (c) Give three characteristics of a CPU that can affect its performance. 1 2 3 6(a) A car has a ‘Follow Me’ system that uses a cruise control feature to allow the car to follow the car in front of it. It will keep the same speed and distance without the driver’s intervention. The cruise control system is an example of an embedded system. Explain the reasons why the ‘Follow Me’ system is an example of an embedded system. © OCR 2024. You may photocopy this page. 11 of 15 Created in ExamBuilder  (b) The car’s system has Read Only Memory (ROM) and Random Access Memory (RAM). (i) State two items that will be stored in the ROM for the ‘Follow Me’ system. 1 2 (ii) The RAM will store currently running data and instructions. State three items of data that will be stored in the RAM for the ‘Follow Me’ system. 1 2 3 (iii) Explain why the ‘Follow Me’ system does not need virtual memory. 7 Kerry wants to buy a new computer, but she does not understand what the different parts of a computer do. Kerry has 5GB of files to transfer from her laptop at work to her new computer. She has been told to buy an external solid state device to do this. (i) Give one example of a solid state device. © OCR 2024. You may photocopy this page. 12 of 15 Created in ExamBuilder  (ii) Identify whether the device given in part (i) is an example of primary or secondary memory. (iii) * Kerry was originally going to use an optical storage device to transfer her files. Discuss whether an optical or solid state device is the most appropriate media to transfer these files. You may want to consider the following characteristics in your answer: portability robustness capacity cost © OCR 2024. You may photocopy this page. 13 of 15 Created in ExamBuilder © OCR 2024. You may photocopy this page. 14 of 15 Created in ExamBuilder  (iv) The filesizes of Kerry’s files are usually displayed in megabytes (MB) or gigabytes (GB). Calculate how many MB are in 5GB. Show your working...........................................MB END OF QUESTION PAPER © OCR 2024. You may photocopy this page. 15 of 15 Created in ExamBuilder Powered by TCPDF (www.tcpdf.org)