Higher Homework
- 1. Higher Computing Homework St Machar Academy
- 2. Homework 1 Give two reasons why computers use the binary number system. Convert each of the following decimal numbers to their binary equivalent. a) 23 b) 45 c) 100 d) 255 Convert each of the following binary numbers into their decimal equivalent. a) 1010 b) 100000 c) 101011 d) 11111111 Give two reasons why using a sign bit to represent numbers is impractical. Convert the following decimal numbers to 2’s complement form using an 8 bit string of digits. a) –3 b) – 35 Floating point numbers are stored using a mantissa and an exponent. a) What effect will increasing the size of the mantissa have? b) What effect will increasing the size of the exponent have? a) The 7 bit ASCII code can represent how many different characters? b) Explain what method is used to encode Unicode. a) Explain what is meant by the resolution of a graphic b) Explain what is meant by the term bit-depth. Give one advantage and one disadvantage of using bit mapped graphics. Describe two advantages of using vector graphic representation. Computer Systems Computer Systems 2 2 2 2 2 2 2 2 2 2
- 3. Computer Systems Computer Systems Homework 2 What are the main components of a computer? What is the purpose of the system bus and what type of information is it likely to transmit? Explain the system of events in the fetch execute cycle. The computer has two types of memory, RAM and ROM. What are the differences between the two and what is the main purpose of each type? Name the three parts of the CPU. The control bus is not really a bus at all but a collection of lines which send signals to other parts of the computer. (a) Describe the function of three such lines. (b) Explain why the address bus is uni-directional. (c) Explain the function of the data bus. Explain the concept of addressability with reference to the address bus. A computer has a 32 bit address bus and a 64 bit data bus. a) What is the word length of this computer? b) What is the maximum amount of memory that can be addressed by this computer? c) Without reference to cost, why might this computer not have the maximum amount of memory? d) What effect on the computer’s performance would there be if the width of the data bus were increased? 2 2 2 2 2 2 1 1 2 1 1 1 1
- 4. Computer Systems Computer Systems Homework 3 What factors can influence the MIP rate of measuring performance? Explain what is meant by the cycle time with reference to the clock speed. Explain why two computers rated at the same clock speed may not have an equivalent performance. Explain what is meant by a benchmark test in measuring a computer’s performance and give an example of one such benchmark. Explain the effect of the width of the data bus on a computer’s performance. Why is an interface needed to connect peripherals to the system bus? Describe the standard functions of an interface. Explain the difference between serial and parallel transmission. Explain why the increase in the width of the data bus can improve system performance. Explain why the increase in the width of the address bus can improve system performance. 2 2 2 2 2 2 2 2 2 2
- 5. Computer Systems Computer Systems Homework 4 A peripheral device captures colour images and saves them to memory. a) Describe how the color is represented using 24 bits b) The image is saved with a resolution of 600dpi. How many pixels are required to save an image of 6” x 4”. Give your answer in MB and show your working. Explain how a buffer is used with a peripheral. Explain the concept of spooling illustrating your answer with an example. State the hardware required in terms of peripherals to set up a computer system to produce a catalogue for a garden centre. The finished catalogue will be taken on electronic media to a printers. Justify the choice of two of these devices in terms of resolution, capacity, speed, cost and compatibility. Describe the features, uses and advantages of a solid state device such as a USB flash drive. a) What is the purpose of an interface? b) State the factors that have to be resolved by an interface. 8. Describe the difference between parallel and serial interfaces 1 2 2 2 2 2 4 1 2 2
- 6. Computer Systems Computer Systems Homework 5 Explain the difference between LAN’s and WAN’s with reference to transmission media, bandwidths and geographical spread. Explain the difference between a mainframe computer with terminals and a network of computers. Explain the differences between client server and peer-to-peer networks. On a LAN describe the functions of file, print and web servers. Describe a bus topology in terms of nodes and channels. Describe the consequences of failure of a node and a channel. Describe the functions of a hub, switch and router on a network with particular reference to the differences between a hub and a switch. Explain why a network computer needs a network interface card (NIC). Explain briefly why networks are becoming increasingly widespread. Explain how a virus may be spread to a computer and how it then may take effect. The access a user has on the network depends on their permissions. Explain what is meant by permissions giving as an example the permissions you may have on your own folder and a shared folder on the network. 2 2 2 2 2 2 3 1 2 2
- 7. Homework 6 Computer Systems Computer Systems Describe the function of a bootstrap loader program. Briefly describe the main purpose of each function of a single-user operating system Describe the purpose of each of: - a) Virus checker b) Disk defragmenter Explain why there is a need for standard file formats. Describe the differences between a JPEG and GIF graphic. Describe the types of software that are required to produce a school web site and explain why you chose these types. Identify the data objects and the operations that can be performed on them in the context of a spreadsheet program. When selecting an Application package to perform a certain task the software compatibility needs to be addressed. Describe the checks that need to be made for each of memory requirements, storage requirements and operating systems. Computer viruses are classed by three main types, file virus, boot sector virus and macro virus. For each type describe how the virus is delivered and how it operates. Describe the anti-virus technique of heuristic detection. 1 3 2 2 1 3 2 2 3 1
- 8. The software development process consists of seven stages. Name the seven stages in order. The software development process is an iterative process. Explain the term iterative as used in this case. Name the documentation normally produced during the software development process. The software should have an appropriate user interface. Describe the factors that should be taken into account when an appropriate user interface is designed. Describe what is meant by efficient computer software. Describe what is meant by maintainable computer software. Software Development Software Development Homework 7 2 2 2 2 1 1
- 9. Explain why, in the process of software development, the Waterfall Model emerged. Why may software developers not get the software correct at the first attempt? Explain why regular feedback to members of the development team is important. Which process describes breaking a complex system down into more manageable components. Which document in the software development process is a legally binding contract? What is the outcome of the analysis stage used to ascertain? What characteristics define software as robust? Describe what is included in the functional specification. Software Development Software Development Homework 8 2 2 1 1 1 1 1 1
- 10. Explain the purpose of testing at the implementation stage. Explain the purpose of debugging software. Explain the difference between testing and debugging. Explain the purpose of test data. What is meant when we say that software is fit for purpose? Why is internal documentation important at the implementation stage? Describe two reasons why maintenance may be needed by software. What is the advantage to a programmer to use modules from a module library? An array holds lists of student names and their marks in a test. Which standard algorithm would be used to find: - a) David Black b) The number of students scoring over 70% c) The top mark d) The bottom mark Software Development Software Development Homework 9 1 1 1 1 1 1 1 1 2
- 11. Why is the design of the human computer interface so important? Describe three types of maintenance activity. What must be considered when creating test data? What is acceptance testing? What is the purpose of a structured walkthrough? A program can be described as correct but not necessarily efficient. How can this statement be true? Why does the use of a module library speed up the software development process? Software Development Software Development Homework 10 1 2 1 1 2 1 2
- 12. Explain what structure diagram is. What is the purpose of pseudocode? Why must suitable test data be chosen to test a program? What factors must be considered when creating test data? What is meant by using test data in a dry run? What are CASE tools? Explain why a program may be described as robust. Explain why a program may be described as reliable. Explain why a program may be described as portable. Software Development Software Development Homework 11 1 1 1 2 1 1 1 1 1
- 13. What are the five groups of key personnel involved with a software development project? What is a systems analyst? Describe three techniques used at the analysis stage of a software development process. What is a requirements specification? Describe briefly the role of the project manager. What is the purpose of systems analysis? Describe each of: - The requirements elicitation. The requirements specification. Software Development Software Development Homework 12 1 1 2 1 1 1 3
- 14. Describe two features in a procedural language which make it suitable for solving scientific problems. Describe two features of a declarative language. Define an event in an event driven programming language. Describe a benefit of using a scripting language. Give a reason why there was a need for scripting languages to develop. A program can be compiled or interpreted to translate it from a high level language to machine code. Describe the difference between the two. Give an example of an object-oriented language and describe briefly how an object-oriented language may work. Software Development Software Development Homework 13 2 2 1 1 1 2 1
- 15. Multimedia Technology Multimedia Technology Homework 14 Explain what a storyboard is used for and give examples of the type of information it might contain. Give an advantage of using a WYSIWYG package for developing multimedia. Describe one difference between an Authoring package and a Presentation package. What is an embedded file and why one might be useful? What is the function of a Codec? Describe a situation where a Hardware Codec may be used. Describe what a container file is and give two advantages of using one. 3 1 2 2 2 3 1
- 16. Outline the difference between images stored as bit-mapped and images stored as object-oriented graphics. What are the main advantages of storing graphics as object-oriented graphics. Explain the term “resolution independence”. Explain how the following types of graphical elements are captured. Refer to the file formats and how the graphics are used in multimedia presentations: Clip art images Graphs and charts and original drawings Small animations suitable for Web pages What is meant by the resolution and colour density of a graphic? For what reasons may they be reduced? Explain the difference between an interlaced and a non-interlaced graphics file. Give a reason why an interlaced file may be more appropriate for use on web pages Calculate the size of a GIF file which has a resolution of 800x600. Show all working. Describe what interpolation is and when it might be used. Multimedia Technology Multimedia Technology Homework 15 2 2 2 3 3 2 2 3 3
- 17. In what type of file format is a colour scanner likely to save an image it has scanned? Explain the process of how a digital camera records an image on its storage device, mentioning specifically the storage medium and the file formats likely to be used. For the file formats TIFF, JPEG and GIF state:-· the type of file format which is used the size implications of using each format in detail how each file format is stored Explain what is meant by Dithering and give a situation where it would be required. Calculate the storage space required for a graphic which is 6 x 4 inches and has a resolution of 1200x1600 and is in true colour. Show all working. Explain the role of a CCD in a digital camera Explain the benefit of using a camera which has 3 CCD’s instead of a single CCD Multimedia Technology Multimedia Technology Homework 16 1 5 3 3 3 2 2
- 18. Describe two developments in sound card technologies. Digital Signal Processing (DSP) is a feature of interface cards. What role does DSP play in these cards? If a 20 second sound recording is sampled at 11kHz, with 8 bit resolution in stereo, what size would the file produced be? Show all your working. If the sound clip is going to be available on the web then a standard file format should be used to store it. Give two reasons why a standard file format is most useful in this case? Describe (giving appropriate values) what is meant by a CD quality sound file. What is meant by ‘normalisation’ and why is it used? What is clipping? Why does this happen? State two differences between stereo sound and surround sound . Multimedia Technology Multimedia Technology Homework 17 2 2 2 4 2 2 2 2
- 19. ADPCM is a method of compressing PCM data. Describe how ADPCM works. Do MP3 files use s lossy or lossless method of compressing sound files? Give a reason for your answer. Why are MP3 files the type of sound file most commonly used for distributing music over the Internet? A MIDI sound file is stored in the same way as a vector graphic – by storing the attributes. Name and describe three attributes which are stored in a MIDI file. Why are MIDI files so popular for storing synthesized sound? Give one advantage of Firewire over USB for data transmission Explain two differences between WiFi and Bluetooth. Explain what is meant by Holographic storage and give an advantage of Holographic storage over CD or DVD. Multimedia Technology Multimedia Technology Homework 18 2 2 6 2 1 1 2 3
- 20. Multimedia Technology Multimedia Technology Homework 19 4 2 4 4 Describe one advantage and one disadvantage of using streaming to deliver a music video over the net in terms of Content Delivery and in terms of Copyright Protection. Describe how video is stored using AVI Describe how video is stored using MPEG Give an example of how a timeline would be used in video editing. Describe two types of transition which can be used to link video clips. Calculate the size of a 25 second video clip which was recorded at 25fps, in 256 colours, in PAL format (768x576). Show all your working. Calculate the size of a 90 second, full colour video clip filmed using a 3.2 megapixel video camera at 25 fps. Show all your working 2 1 2