Task 1 – Getting it! - Homepage | Ark Acton Academy



5703405-10811600OCR Computer Science: Year 11 Homework pack Spring 1Name: ……………………….Our spring 1 Homework Programme.ContentApproximate Time NeededIs there help?Where can I find it?Week #1Homework 1 : Images 45 minutes Knowledge organiser, bbc bitesize, youtbe, OCR revision books, Mr Frazer’s websiteWeek #2Homework 2: Characters 45 minutes Knowledge organiser, bbc bitesize, youtbe, OCR revision books, Mr Frazer’s websiteWeek #3Homework 3: Binary Representation 45 minutes Converting Denary to Binary bbc bitesize, youtbe, OCR revision books, Mr Frazer’s websiteWeek #4Homework 4: 45 minutes Converting Binary to Denary bbc bitesize, youtbe, OCR revision books, Mr Frazer’s websiteWeek #5Homework 5: Wired & Wireless Network 45 minutes LAN vs WANbbc bitesize, youtbe, OCR revision books, Mr Frazer’s websiteWeek #6 -HalfTermHomework 6: Network Hardware 45 minutes Knowledge organiserbbc bitesize, youtbe, OCR revision books, Mr Frazer’s websiteWeek #7Homework 7: 45 minutes Knowledge organiserExam style questions on Network/Internetbbc bitesize, youtbe, OCR revision books, Mr Frazer’s websiteWeek #8Homework 8: The Internet 1hr Knowledge organiser & Packet switchingbbc bitesize, youtbe, OCR revision books, Mr Frazer’sWeek #9Homework 10: System security & Network threats 45 minutes bbc bitesize, youtbe, OCR revision books, Mr Frazer’s websiteWeek #10 Homework 11: Secondary Storage 1hr bbc bitesize, youtbe, OCR revision books, Mr Frazer’s websiteWeek # 11Homework 12: Logic gates 1hr bbc bitesize, youtbe, OCR revision books, Mr Frazer’s websiteImages: Homework 1Task 1 – Getting it!This image uses four colours so requires 2 bits per pixel. Shade in the image as a computer using the key. 1010101010101010101010101010100000100000100000100000001010000010000010000010000000101010101010101010101010101010100000100000100000100000001010000010000010000010000000101000111010101010101010101010101111101010101010101010010110101010111110101010111110100000000011110000000011110000Key:01001110What is meant by the resolution of an image?6077585238760[1]00[1]…………………………………………………………………………………………..Describe how a black and white image could be represented in binary,6118860325755[3]00[3]Task 2 – Got it! Describe what is meant by colour depth6061075161290[1]00[1]How many bits per pixel (colour depth) would be required for an image with a palette of 256 possible colours? 6071870172720[1]00[1]6149975508000[2]00[2]Additional metadata data is stored alongside the binary colour values for each pixel. Give two examples of metadata.Task 3 – Google Hire Me!60210701289685[6]00[6]Calculate the file size of the following images:Image ResolutionNumber of coloursColour depth in bitsFile size in bitsFile size in BytesImage 120 x 208Image 210 x 108Image 320 x 204 2. Which icon image is greater in file size? (Show your working) A 256 colour icon with dimensions of 50 x 50 pixelsA 16 colour icon with dimensions of 100 x 100 pixels6021070300355[2]00[2]State 2 factors that affect the file size of a bitmap image6079490254635[2]00[2]Explain the relationship between image quality and file size 6063615207010[2]00[2]0307975Total Marks [20]00Total Marks [20]Characters: Homework 2Task 1 – Write your initials in binary digits below using the ASCII table:5995670243840[1]00[1]Using the 8-bit ASCII set, what would be the total size in bytes of the words ‘Computer Science’?601662568580[1]00[1]What is meant by a character set?604583590170[1]00[1]4.Integers which are to be used in calculations are represented as pure binary numbers. 6052185128270[1]00[1](a)What is the pure binary representation of the number 76? (b)The ASCII character 7 is represented by the denary number 55. 609092057785[1]00[1]Convert the ASCII string ‘76’ to binary.Task 2 – Got It! 1. A simple three-letter code word is saved to a personal disk.59848756985[1]00[1](a)What is the size in bytes of the code word? (b)The code word is represented on the disk in a binary format, saved as:01000011 01000001 010000105993765109220[1]00[1]Using the section of the ASCII table above, what is the code word? .2. The eighth bit is used to give an extra 128 characters. Any character in the ASCII table can be typed using the ALT key in combination with its ASCII code. For example, if you type ALT + 065 on the numeric keypad, the letter A will appear.What is the binary representation of the letter A? 6042660143510[1]00[1] Typing ALT + 0233 will produce é.What is the binary representation of the letter é?6019800339090[1]00[1]Task 3 – Google Hire Me!How many characters can be represented with the 7-bit ASCII character set? 6042660142875[1]00[1]2.(a)What are the limitations of the 8-bit extended ASCII character set?6116955252095[1]00[1]6170295259715[1]00[1](b)How can these limitations be overcome?3. The function ord(a) returns the denary value of the ASCII representation of the character a.The function chr(i) returns the character whose ASCII code is the integer i .The ASCII representation for A is 65 (denary). What will be printed when the following program is run?x = ord(‘C’)y = x + 3z = chr(y)print (x,y,z) …………………………………………………………………………………………………………6099810338455[1]00[1]4. A programmer writes the following lines of code in Python. All data is input as ASCII characters.print("Please input an integer x: ")x = input()print("Please input a second integer y:")y = input()z = x + yprint ("x + y = ", z)The user enters 7 and 4. What will be printed? Explain your answer.6016625313690[1]00[1]5. The programmer changes the second and fourth lines to readx = int(input())y = int(input())The user enters 7 and 4. What will be printed? 6016625290830[1]00[1]The programmer changes the program to the following:print("Please input an integer x: ")x = input()print("Please input a second integer y:")y = input()z = x - yprint ("x - y = ", z)What will happen when the program is run? Why? 6130925275590[2]00[2]ASCII CodesDecimalBinaryCharacterDecimalBinaryCharacterDecimalBinaryCharacter3200100000space6401000000@9601100000'3300100001!6501000001A9701100001a3400100010"6601000010B9801100010b3500100011?6701000011C9901100011c3600100100$6801000100D10001100100d3700100101%6901000101E10101100101e3800100110&7001000110F10201100110f3900100111'7101000111G10301100111g4000101000(7201001000H10401101000h4100101001)7301001001I10501101001i4200101010*7401001010J10601101010j4300101011+7501001011K10701101011k4400101100,7601001100L10801101100l4500101101-7701001101M10901101101m4600101110.7801001110N11001101110n4700101111/7901001111O11101101111o480011000008001010000P11201110000p490011000118101010001Q11301110001q500011001028201010010R11401110010r510011001138301010011S11501110011s520011010048401010100T11601110100t530011010158501010101U11701110101u540011011068601010110V11801110110v550011011178701010111W11901110111w560011100088801011000X12001111000x570011100198901011001Y12101111001y5800111010:9001011010Z12201111010z5900111011;9101011011[12301111011{6000111100<9201011100\12401111100|6100111101=9301011101]12501111101}6200111110>9401011110^12601111110~6300111111?9501011111_12701111111del-511810-254002.6 Data Representation002.6 Data RepresentationBinary Representation – Homework 3Converting Denary to Binary Numbers310832566675Why do computers use binary?00Why do computers use binary?-38735066675What is Binary?00What is Binary?Complete the table below:No of bits/bytes Common description of bits/bytes a 1 or a 0 (b) 1 nibble 8 bits 1 Kilobyte (KB) 1024 Kilobytes 1 Gigabyte (GB) 1024 Gigabytes 1024 TerabytesTask 1Denary = 6Answer in binaryCalculation for answer2 + 4 = 6128643216842100000110Task 2Denary = 15Answer in binaryCalculation for answer1286432168421Task 3Denary = 21Answer in binaryCalculation for answer1286432168421Task 4Denary = 39Answer in binaryCalculation for answer1286432168421Task 5Denary = 54Answer in binaryCalculation for answer1286432168421Task 6Denary = 78Answer in binaryCalculation for answer1286432168421Task 7Denary = 99Answer in binaryCalculation for answer1286432168421Task 8Denary = 106Answer in binaryCalculation for answer1286432168421Task 9Denary = 180Answer in binaryCalculation for answer1286432168421Task 10Denary = 200Answer in binaryCalculation for answer1286432168421Converting Binary to Denary Numbers: Homework 4Calculating a denary number from a binary numberExample 1: binary number = 0000001112864321684210000001100000021Answer2 + 1 = 3Example 2: binary number = 0000101112864321684210000101100008021Answer8 + 2 + 1 = 11Task 12: binary number = 00001111128643216842100001111AnswerTask 13: binary number = 00101010128643216842100101010AnswerTask 14Write the formula in working out the binary numbers:…………………………………………………………………………………………………………Task 15Explain why binary numbers known as machine codes……………………………………………………………………………………………………………………………………………………………………………………………………………………Task 15: binary number = 01011011128643216842101011011AnswerTask 16: binary number = 001011011286432168421AnswerTask 17: binary number = 110011001286432168421AnswerTask 18: binary number = 111000101286432168421AnswerTask 19: binary number = 011010011286432168421AnswerExplain why binary number is base 2…………………………………………………………………………………………………..…………………………………………………………………………………………………..Explain why denary number is base 10…………………………………………………………………………………………………..…………………………………………………………………………………………………..Explain why Hexadecimal is base 16………………………………………………………………………………………………….Wired and Wireless Homework 5 Task 1: LAN vs WANKey point to researchLANWANHow big is the area that this type of network covers?Geographically small?Geographically large?How are computers normally connected together in this type of networkWired (Ethernet)WirelesslyDedicated LinesLeased LineThe InternetSatellitePhone LinesWhat is the average speed of data transmission on this type of network?Kbps?Mbps?Gbps?What kind of costs is involved in setting up this type of network?Initial purchase of hardware?On-going costs (subscriptions)?Cable costsHow secure is this type of network?What security risks are there?What could be done to help the security?Can you give an example of this type of network?Advantages of Networks: Task 2 – Client Server vs Peer to PeerTick the correct box(es) to show whether the statement applies to a client-server, a peer-to-peer or both networks.StatementClient-ServerPeer-to-peerComputers are networked together.It has a central computer that provides all the services to the network.Each computer in the network is equal, there is no central computer controlling services.Most commonly found in a home or small office.Most commonly found in larger offices and organisations.Files can be automatically backed-up to a central location from each computer on the network.Peripherals on the network can be shared.An expensive network to set up as more hardware needs to be purchasedA cheaper network to set up as less hardware needs to be purchasedFiles can be shared using the network.Each computer on the network needs to be maintained separately.Task 3 – Performance of NetworksList the factors that could affect the performance of a network Name the type of Network we use at home…………………………………………………………………………………………………………………………….Homework 6: Network Hardware: Task 1In order to connect to and set up a network you need the following hardware. Describe the role of each:Wireless Access PointRouter/SwitchNetwork Interface Card (NIC)Transmission MediaTask 2 – The CloudWhat is the Cloud? AdvantagesDisadvantagesTask 3 – MatchingTermDefinitionCoaxial cableThe least expensive transmission media that consists of two wires that wrap around each other. Used as a standard (Ethernet)RouterConnects together different networks and forwards data packets along a network.Wireless access pointA transmission media that consist of a central wire, surrounded by insulation and a shield of braided wire to minimise interference.SwitchA connection point for devices in a network. Unintelligent – packets are broadcast to every device.Twisted pair cableA device that allows other devices to connect to a network using standards such as Wi-Fi and work interface cardA transmission media that consists of a bunch of glass or plastic threads.Fibre optic cableA hardware device internal to a computer that allows a computer to connect to a network.HubFilters and forwards data packets within a single network. This creates a direct connection between devices (intelligent)Task 4 – Domain Name System and HostingWhat is a DNS Server?What is Hosting?What is meant by the Internet?Exam Style Questions on Network/Internet: Homework 71.Tick a column to show whether the following statements are true or false: [2]TrueFalseThe worldwide web is an example of client-server computingA local area network may be configured as a client-server network 2.The diagram below shows the computers for a small accountancy firm connected together in a local area network.(a)Does the diagram show peer-to-peer network or a client-server network?[1](b)What is the device A which connects to the Internet?[1]977900169546ComputerComputerComputerAServerInternet00ComputerComputerComputerAServerInternet(c)Name three functions of the server in this network.[3](d)Name three advantages of linking computers in a small office in a peer-to-peer network.[3]3.The accountancy firm uses a file hosting service in the Cloud to manage their files and data.(a)Briefly describe what is meant by ‘The Cloud’[2](b)Give two advantages to using cloud-based services over local storage. [2] (c)Office staff notice that the network is running slowly compared to their home network connections.Explain two factors that can affect network performance.[4](d)State two types of network transmission media.[2][Total 20 marks]The Internet and Packet SwitchingHomework 8Task 1: The Internet - TrueFalseThe Internet is part of the World Wide WebEach household in the UK has a unique IP addressThe IP address of a laptop will change as you travel to different places Every networked device in the world has a unique MAC (Media Access Control) address To use the Internet, you must be connected to a router, either by cable or using a wireless connectionTask 2 – Star and Mesh TopologiesDraw and label diagrams for the 2 topologiesStarMesh5394960-36258500Task 3 Wifi and Ethernet EthernetFrequency and ChannelsTask 4 – Packet SwitchingPacket = data sent between networks is split into smaller sized chunks called packets. 198451324061000Contents of a Packet1984513292380019845136899400Explain with the aid of a diagram the concept of a packet switching network.Task 5 – ProtocolsProtocol NameFull NameWhat does it do?When would I use it?TCP/IP Transmission Control Protocol/Internet ProtocolDefines how data is sent and transmitted and received over the internet. Defines four ‘layers’ for the transmission of data.Hyper Text Transfer ProtocolHyper Text Transfer Protocol SecureWhen accessing a webpage/website where you may want to encrypt data – e.g. a Bank website.File Transfer ProtocolAllows the transfer of files between computersPOP Another email protocol that us used to retrieve email from mail servers. This is a more recent protocol compared to POP.SMTPTask 6 - LayersLayer NameProtocols in this layerProtocol ExamplesIP80327410414000 TCP7988295270500Ethernet953769-3111500FTPSystems Software – Homework 9Systems Software = Software designed to maintain and control the hardware, it also provides and interface between software and hardware. The two main types of systems software are operating systems and utility programsOperating system = controls the hardware and software/provides and interface for the userUtility programs = help to maintain the computerTask 1 – Operating SystemWhat do you think an operating system does? Use the images to give you a few ideas. Task 2 – Functions of an Operating System Notes:Explain what is meant by memory management and multitasking and why it benefits the user: [4 marks]Describe 2 other features of an operating system [4 marks]What is meant by a peripheral and a driver? [2 marks]Task 3 – Utility Software-25400012700000EncryptionWhat it is = Benefit = -16827514541500DefragmentationWhat it is = Benefit = 413067512382500CompressionWhat it isBenefit = -16954518542000BackupWhat it is=Benefit = Full vs Incremental BackupFullIncrementalDescriptionAdvantagesDisadvantages391541035814000Systems Security – Homework 10 Network ThreatsTask 11.Look at the following text message. What action should the recipient take?Give reasons for your answer:20732758255Total Marks 200Total Marks 2[2]2. Do some research on Denial of Service attacks and write up your findings. Be sure to include answers to the following questions. [5]What is a DoS attack?Who is typically targeted?Who does it typically affect?Is it always intentional?How can it be countered?…………………………………………………………………………………………………………………….3.Study the email on the following page. Describe three clues which indicate that it is a phishing scam. [3]50038002834640Total Marks 800Total Marks 8Task 2: Identifying and Preventing VulnerabilitiesWhat might a company put in its own Acceptable use policy and why? [2]2.Explain the purpose of penetration testing.[2]3.List two items of information that you would expect an audit trail carried out by the computer department of an organisation to provide. [2]4.Describe two measures that a school could take to ensure the security of the school network.[4]483502897763Total Marks 1000Total Marks 10Key TermDefinitionMalwarePhishingBrute ForceDenial of ServiceTask 3: Key Words on Network security State definition of each key wordKey TermDefinitionSocial EngineeringSQL InjectionNetwork PolicyPenetration TestingNetwork ForensicsFirewallsUser Access LevelsStrong Password Features-21971011684000Secondary Storage – Homework 11Task 1OpticalMagneticSolid State/FlashMain Features of Operation:Advantages:Disadvantages:Main Features of Operation:Advantages:Disadvantages:Main Features of Operation:Advantages:Disadvantages:Task 2:DeviceMagneticOpticalSolid StateHard Disk DriveSolid State DriveBlu-rayDVD ROMSD CardUSB Memory StickCD ROMTape DriveFor the devices listed below tick one bow to show which type of storage it is:Task 3:Complete the table below using High, Medium or Low as appropriate for each storage medium. Some devices do not necessarily have a right or wrong! CapacitySpeedPortabilityDurabilityReliabilityCostHDDSSDCDDVDBlu-RayUSB Flash MemoryTask 4: Calculating File SizesEstimate the following file sizes: A text file that contains 10000 characters. Give your answer in KB……………………………………………………………………………………………………………………………….……………………………………………………………………………………………………………………………….An image is 2030 x 1000 pixels in size. It has 65536 colours. Give your answer in GB.……………………………………………………………………………………………………………………………….……………………………………………………………………………………………………………………………….A sound file has 4 bytes per sample. It takes 100 samples per second, over 1 channel and is 2 minutes 30 seconds long. Give your answer in KB.……………………………………………………………………………………………………………………………….……………………………………………………………………………………………………………………………Logic Gates Workbook: Homework 12 Question 1The diagram below is for a NOT gate. Complete the truth table for this gate.AQ0112628900476885?A00?AQuestion 2The diagram below is for an AND gate. Complete the truth table for this gate2590800207645A B^00A B^ABQ000011011Question 3The diagram below is for an OR gate. Complete the truth table for this gate.2600325422275AvB00AvBABQ000011011Question 4Complete this table to show every possible combination of logic inputs for A and BAB00Question 5Complete this table to show every possible combination of logic inputs A, B and CABC0000010100111Question 6.Logic gates can be combined to make a circuit. You can use partial tables to help work out the complete truth table for the circuit. The complete truth table only ever includes the actual inputs plus the final output but not the in-between points.Fill out all possible values of B in the logic circuit shown aboveAB0001113319780-25146000Complete the truth table for point P ABP000011011Complete the truth table for Q given every value of P from above.?PQ0111Now use the above tables to complete this truth table.ABQ0001101131292807302500Question 7Complete the truth table for this circuit. ABQ000011011Question 8143446531940500The logic circuit below has 3 inputs and so there are 8 possible combinations of A, B and C.a) Complete the table below to show all the possible values of A, B and CABC00000101001111b) By using the table above, fill out the possible values of the OR gateABCA v B000001010011100101110111Now work out every value of Q for the circuitABCA v BQ00000101001110010111001111Question 9This logic circuit is for an AND gate. This AND gate can be written as Q = A AND B42964103238500Now write down the equivalent statement for the OR gate for the logic circuit on the rightSTATEMENT: Question 10Write down the logic statement for the gate shown belowSTATEMENT: Question 11Logic gates can be combined to make more complicated circuits such as the one below. Work out the logic statement for this circuit. We have given you a few hints to start you offFill out the statement for PP = A OR .........This is the statement for Q given PQ = NOT (P)Now fill out the complete logic statement belowThereforeQ = NOT ( A ........ B) Write the statement replacing the words with the correct symbolsQUESTION 12Complete the logic statements for this circuitSTATEMENT:P = A .................Q = NOT (.......)ThereforeQ = NOT(........................)Question 13Complete the logic statement for this circuitSTATEMENT:P = ...................Q = P ............... BTherefore the final statement isQ = .......................................ExampleYou can draw a logic circuit directly from a logic statement. For example, the logic circuit for the statement Q = C AND (A OR B) looks likeQuestion 14Draw the logic circuit for Q = C OR (A AND B)Question 15Draw the logic circuit for the statement Q = A AND (B OR C) ................
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