Chapter 1 Final Revision Chapter 1 1 2 1 Eng. Omar El Safty Chapter 1 Final Revision 3 2 Eng. Omar El Safty Chapter 1 4 Final Revision Eng. Omar El Safty A sports stadium has an electronic counter that counts each person that enters the stadium. The count is stored as binary in a 16-bit register. A denary value of the count is displayed on a screen at the entrance. (a) The screen currently displays: Give the binary value that is stored in the register to display the count shown. Binary value: ............................................................................................................................. Working space ................................................................................................................................................... ................................................................................................................................................... ...............................................................................................................................................[2] (b) More people enter the sports stadium and the screen now displays: Give the binary value that is stored in the register to display the count shown. Binary value: ............................................................................................................................. Working space ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... [2] 3 Chapter 1 Final Revision Eng. Omar El Safty (c) After everyone has entered the stadium, the register stores the binary value: 0000001000000100 Show what the screen will display when this binary value is stored Display: [1] Working space ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... 5 A hockey club records the number of people that watch each match. An 8-bit binary register is used to store this value (a) 46 people watch the first match and 171 people watch the second match. Show how the registers would store these denary values as 8-bit binary. Working space ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... (b) Give the largest denary value that can be stored in the 8-bit binary register. ............................................................................................................................................................ [1] 4 Chapter 1 Final Revision Eng. Omar El Safty (c) The hockey club wants to increase the number of people that can watch each match to 2000. The 8-bit binary register may no longer be able to store the value. Give the smallest number of bits that can be used to store the denary value 2000. ............................................................................................................................................................ [1] 6 5 Chapter 1 8 Final Revision Eng. Omar El Safty Ron is attending a music concert. He has bought three tickets. Each ticket number is displayed as a hexadecimal number. Complete the table to show the 12-bit binary values and the Denary values for each Hexadecimal ticket number. 6 Chapter 1 Eng. Omar El Safty Final Revision Working space ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... 9 A denary value can be converted into hexadecimal and binary. Complete the table to show the hexadecimal and 8-bit binary values of the given denary values. Denary Hexadecimal 8-bit binary 123 [2] Working space ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... 7 Chapter 1 Final Revision Eng. Omar El Safty 10 11 Error codes for a computer are often displayed as hexadecimal values. Each error code is stored in a 12-bit binary register. (a) The error code 404 means ‘file not found’. Give the 12-bit binary value that would be stored for the hexadecimal error code 404 ................................................................................................................................................... Working space ................................................................................................................................................... ................................................................................................................................................... ...............................................................................................................................................[2] 8 Chapter 1 Final Revision Eng. Omar El Safty (b) Hexadecimal values can also be represented as denary values. The hexadecimal error code 0AC means ‘insufficient memory’. Convert the hexadecimal error codes 0AC to denary values. 0AC ........................................... Working space ................................................................................................................................................... ................................................................................................................................................... ...............................................................................................................................................[1] 12 9 Chapter 1 Final Revision 13 10 Eng. Omar El Safty Chapter 1 Final Revision 14 11 Eng. Omar El Safty Chapter 1 Final Revision 15 12 Eng. Omar El Safty Chapter 1 Final Revision Eng. Omar El Safty 16 Hexadecimal is used to represent Hypertext Markup Language (HTML) colour codes in computer science. Identify three other ways that hexadecimal is used in computer science. 1................................................................................................................................. 2 ............................................................................................................................... 3 ...........................................................................................................................[3] 17 18 (a) Give one way that hexadecimal is used in website development. ..................................................................................................................................... [1] (b) Give one way that hexadecimal is used in low-level programming. ..................................................................................................................................... [1] 19 Give three benefits, to users, of converting binary values to hexadecimal. Benefit 1 ........................................................................................................................... ......................................................................................................................................... Benefit 2 ........................................................................................................................... ......................................................................................................................................... Benefit 3 ........................................................................................................................... .....................................................................................................................................[3] 13 Chapter 1 Final Revision Eng. Omar El Safty 20 When planning a game, a game designer decided to use hexadecimal notation to represent the binary values. Explain why the designer used hexadecimal notation. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... .............................................................................................................................................. [2] 21 Give two reasons why error codes are represented in hexadecimal, instead of binary. Reason 1 .................................................................................................................................. ................................................................................................................................................... Reason 2 .................................................................................................................................. .......................................................................................................................................[2] 22 20 MiB 10 GiB 3500 KiB 3 MiB 14 Chapter 1 Final Revision 23 999 KiB 1 MiB 4000 MiB 2 GiB 2 500 000 KiB 24 15 Eng. Omar El Safty Chapter 1 Final Revision Eng. Omar El Safty 25 Data storage is measured using binary denominations. Complete each conversion. 16 bytes = ..............................................nibbles 512 kibibytes (KiB) = ................................................... mebibytes (MiB) 4 gibibytes (GiB) = .................................................. mebibytes (MiB) 3 exbibytes (EiB) =……………………….pebibytes (PiB) Working space ....................................................................................................................................... ....................................................................................................................................... ....................................................................................................................................... 26 Six questions are shown on the left and eight numerical values are shown on the right. Draw lines to connect each question to its correct numerical value (two of the numerical values are not used). ss 16 [4] Chapter 1 Final Revision Eng. Omar El Safty 27 28 Explain the differences between ASCII code and Unicode. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ...............................................................................................................................................[2] 17 Chapter 1 Eng. Omar El Safty Final Revision 29 30 A musician stores his music files digitally on a computer. Complete the table by defining each term about sound files. Image term Definition ................................................................................................................... sampling resolution ................................................................................................................... ...............................................................................................................[1] ................................................................................................................... sampling rate ................................................................................................................... ............................................................................................................. [1] 18 Chapter 1 Final Revision Eng. Omar El Safty 31 An image is stored on a computer. The image is 16-bit colour and is 100 pixels high and 150 pixels wide. Calculate the file size of the image in bytes. Show all your working. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... Answer ................................................ bytes [3] 32 5 images are to be stored electronically. Each image is 256 pixels high by 200 pixels wide with a 16-bit colour depth. Calculate the file size of the image in KiB. You must show all of your working. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... Answer ................................................ KiB [3] 33 A soundtrack has duration of 2 minutes and it’s sampled 1024 times per second. Each sample is 16 bits. Calculate the size of the soundtrack in KiB. Show all your working. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... Answer ................................................ KiB [3] 19 Chapter 1 Final Revision Eng. Omar El Safty 34 An image has resolution of 4096 x 2048 pixels. The image’s color depth is 16 bits. Calculate the size of the image in (MiB). Show all your working. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... Answer ................................................ MiB [3] 35 (a) How many mebibytes (MiB) of storage would be needed to store 256 photographs each of which are 8 MiB in size. ................................................................................................................................................... ................................................................................................................................................... ...............................................................................................................................................[1] (b) Write your answer from part (a) in gibybytes (GiB). ................................................................................................................................................... ...............................................................................................................................................[1] 36 20 Chapter 1 Final Revision Eng. Omar El Safty 37 Two 8-bit binary values are given. Add the two 8-bit binary values. Give your answer in binary. Show all your working. [3] 38 (a) Two 8-bit binary values are given. Add the two 8-bit binary values. Give your answer in binary. Show all your working. [3] (b) Two 8-bit binary values are added. The result of this calculation needs to be stored in an 8-bit register. The denary result of this calculation is 300. This generates an error. State the name of this type of error and explain why this error occurs. Error name ................................................................................................................................ Explanation ............................................................................................................................... .................................................................................................................................................. .................................................................................................................................................. 21 Chapter 1 Eng. Omar El Safty Final Revision .....................................................................................................................................[3] 39 (a) Negative denary numbers can also be represented as binary using two’s complement. Complete the binary register for the denary value −62. You must show all your working. Working space........................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... Register: [2] (b) Complete the following table to show the denary value of the given binary values in 2’s complement format. 2’s complement binary denary 10000111 01100011 [2] Working space ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... 22 Chapter 1 Eng. Omar El Safty Final Revision 40 (a) Negative denary numbers can also be represented as binary using two’s complement. Complete the binary register for the denary value −58. You must show all your working. Working space........................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... Register: [2] (b) Complete the following table to show the denary value of the given binary values in 2’s complement format. 2’s complement binary denary 10100101 01110001 [2] Working space ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... 23 Chapter 1 Final Revision 41 24 Eng. Omar El Safty Chapter 1 Final Revision 42 25 Eng. Omar El Safty
