1.     How many types of computer are there? What are they? Describe each type of them

There are 7 types of computer. They are mainframe, minicomputers, microcomputers (PCs), laptop, notebook, subnotebook and handheld(palmtop).

-      Mainframe: large, powerful, expensive. Multi-user system – used by many people at the same time. Used for processing very large amounts of data. The most powerful mainframes are called supercomputers.

-      Minicomputers: Used like mainframes. Not as big, powerful or expensive as mainframes. Less common now because microcomputers have improved.

-      Microcomputers (PCs): The most common type of computer. Smaller, cheaper, and less powerful than mainframes and minicomputers.

-      Laptop: About the size of a small typewriter. Less common now because smaller and lighter portable are available.

-      Notebook: About the size of a piece of writing paper. The most common type of portable.

-      Subnotebook: Not quite as big as notebook. Can fit into a jacket pocket.

-      Handheld (palmtop): small enough to fit into the palm of one hand. Not easy to type with because of their size. Often used as personal organizers.

2.     What is the difference between a mainframe and a PC?

-      A PC is smaller, cheaper and less powerful than a mainframe.

-      A mainframe is a multi-user system used by many people at the same time, a PC is used by a personal.

3.     Write the instructions for virus-checking a disk

-      Put the disk into drive

-      Start the virus checking program

-      Select the drive to be checked

-      Click the ‘Find’ button

-      Don’t exit the program until the check is complete

-      Click ‘Yes’ or ‘No’ for checking another disk

4.     Write the instructions for formatting the disk

-      Put the disk into the drive

-      Choose ‘Format’ from the drop-down menu

-      Choose the formatting options you require

-      Click the ‘Start’ button

-      Select ‘OK’ to start formatting the disk

-      Click the ‘OK’ button when formatting is complete

5.     Name the input devices that you know (at least six). Give further information about: a joystick, a trackball and a scanner.

-      The input devices that I know are joystick, light pen, scanner, digital camera, mouse, keyboard, microphone.

-      A joystick is an input device you can connect to a computer system. The joystick is able to move in eight directions. Joysticks are mostly used in computer games to control the way a picture on the screen moves. Sometimes two joysticks are connected to a computer so two people can play the games at the same time.

-      A trackball works in exactly the same way as a mouse, except that the ball is on top. The user rolls the ball around with his hand to operate it. If you use a trackball, you don’t need any extra space on your desk to move it around. Trackballs are often used on small portable computers and on some video game machines.

-      Using a scanner you can input printed drawing, photographs, or text directly into a computer. A scanner works like a photocopier – a light is shown on the material and the scanner detects the reflected light. You can use a scanner with optical character recognition (OCR) software to input the scanned text into a word processing package.

6.     What are the advantages and disadvantages of a digital camera?

-      Digital cameras don’t use film. You take pictures on to solid state memory, you can download them to a computer. You can manipulate and improve the pictures in your PC. Then you can print them, add them to your website or display them on the screen.

-      Digital cameras are more expensive than film cameras but the cost for each picture is lower because there is no processing. It’s also easy to download the pictures.

7.     What are the advantages and disadvantages of a film camera?

-      Film cameras are cheaper but each picture costs a lot because there are processing costs. The quality of film camera pictures is much better than digital cameras but you have to scan the pictures to transfer images to a PC.

8.     What are the main criteria to choose a good monitor?

-      Price: the price mainly depends on the screen size. Common monitor sizes are 14 inch, 15 inch, 17 inch, and 21 inch. The price also depends on aperture grill pitch, resolution, and the number of controls.

-      Screen size: the size of the screen is the diagonal distance from one corner to another. The actual area for images is smaller than this.

-      Aperture grill pitch: this controls the space between the dots which make up the image. The less space between the dots, the better the display. Most monitors offer 0.28 mm dot pitch but some go as high as 0.31 mm or as low as 0.25 mm.

-      Maximum resolution: the quality of the display depends on the number of dots which make up the image. The more dots, the better the display.

-      Refresh rate: the monitor refreshes the image on the screen all the time. The faster this happens, the less the screen flickers. You should have a refresh rate of at least 72Hz.

-      Safely standards: these are international standards to control harmful signals.

-      Power-saving feature: the power the monitor uses automatically reduces when it is not in use.

-      On-screen menu: digital controls on the screen allow you to adjust the image.

9.     List the main advantages and disadvantages of dot-matrix printer, inkjet and laser printer.

-      Dot-matrix printers are the cheapest kind of printer, but their print quality is low and they are slow and noisy. They’re cheap to run.

-      Inkjet printer: you get better quality and quieter operation but inkjets are relatively slow and also expensive to run.

-      Laser printer gives you the best quality of output. It prints faster than either of the other two types of printers and it costs less to run than an inkjet. It’s great for black and white. Unfortunately, it costs almost twice as much.

10.            What are the four main sections of the keyboard? How are they arranged on the keyboard?

-      The section known as the main keyboard has a key for each letter of the alphabet. It also has keys for the digits 0 to 9, punctuation marks like commas and full stops, and other common symbols.

-      Above the main keyboard is a row of keys known as the function keys. This section includes the Escape key to the left and the Print Screen, Scroll Lock, and Break keys to the right. The function keys labeled F1 to F12 don’t have fixed functions.

-      To the right of the main keyboard is a section known as the editing keys. This group includes keys which insert and delete data. It also includes the cursor keys, also called the arrow keys.

-      To the far right of the main keyboard is the numeric keypad. This section has keys for the digits 0 to 9 and for common mathematical symbols like plus and minus. The keys are arranged like the keys on an electronic calculator.

11.            Name 8 storage devices that you have learnt. Give the Vietnamese equivalence if each device.

-      Floppy disk: đĩa mềm

-      Fixed hard disk: đĩa cứng gắn trong

-      Removable hard disk: đĩa cứng di động

-      CD-ROM disk: đĩa CD-ROM

-      Magneto-optical disk: đĩa từ quang

-      Magnetic tape: băng từ

-      USB

12.            What are the advantages of floppy disks and hard disks?

-      Most computers use floppy disks. Floppies can form to a standard and you can use them to carry data from one place to another. They are also very cheap.

-      Almost all desktop computers have hard disks. They are fast and can store much greater amounts of data than floppies.

13.            What are the advantages of removable hard disks and CD-ROM disks?

-      You can move data from place to place using removable hard disks. They are almost as fast as fixed hard disks and also have high capacities.

-      CD-ROM disks are very common and conform to a standard. They are removable and can hold large amounts of data. They are also cheap to make.

14.            What are the advantages of magneto-optical disks and magnetic tape?

-      Magneto-optical disks are like CD-ROMs, but you can write data on to them. They are removable, have large capacities, and last for a long time.

-      Magnetic tape is a cheap medium. You can use it to store very large amounts of data.

15.            What is a network? What is a LAN? What is a WAN?

-      A network is simply two or more computers linked together. It allows users to share not only data files and software applications, but also hardware like printers and other computer resources such as fax.

-      Most networks link computers within a limited area – within a department, an office, or a building. These are called Local Area Networks, or LANs.

-      Networks can link computers across the world, so you can share information with someone on the other side of the world as easily as sharing with a person at the next desk. When networks are linked together in this way, they are called Wide Area Networks, or WANs.

16.         Describe the main types of topologies

-      => A star topology has a server computer at the centre and a separate cable connecting the server controls the flow of data in the network. If the central server fails, the whole network will fail.

-      A ring topology, each computer is connected to its neighbor in a circle. The data flows in one direction round the ring. If a cable breaks or one of the computers fails, the whole network will be affected

-      A bus topology has all the computers connected to a common cable. The data travels in both directions along cable. If a computer fails or we remove one from the network, it won’t affect the other computers.

17.         What are the main rules to make a good password?

-      The main rules to make a good password:

-      Passwords should

-      -        be at least 6 characters long

-      -        have a mixture of numbers and letters

-      -        have a mixture of capital and small letters

-      -        be easy to remember

-      Passwords shouldn’t

-      -        be a word from a dictionary

-      -        be a common name

-      -        include spaces, hyphens, dots, or symbols with a special meaning in computing. Eg : $,*….

18.         What should we do to protect your system from virus attack?

-      To protect your system from virus attack, we should use anti-virus program and remember to update the anti-virus software frequently. Moreover, we shouldn’t open – email attachment from strange and take care when downloading files from the Web.

19.         What are the possible methods to protect your valuable information from computer hackers when you have the internet connection?

-      The possible methods to protect your valuable information from computer hackers when you have the internet connection are passwords for access control, encryption and decryption systems, and firewalls.

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20.         Why is CPU considered to be the “brain” of computer?

-      Because its function is to execute to execute program instructions and coordinate the activities of all the other unit.

21.         Write the instructions for replacing the motherboard?

-      First, remove the old motherboard.

-      Second, add the processor.

-      Then, add the memory. Don’t touch the contacts.

-      After that, fit the new motherboard

-      Finally, put it back together

22.         What is hardware and software?

-      Hardware is the electronic and mechanical parts that make up a computer system.

-      Software is information in the form of data and program.

23.         What are the basic steps of processing data?

-      First, data is fed into the computer’s memory. Then, when the program is run, the computer performs a set of instruction and processes the data, Finally, we can see the result on the screen or in printed form

24.         What are the three main types of the computer crimes?

-      The three main types of the computer crimes are:

-      Hacking: unauthorized access to computer system and tampering with other users data

-      Pirating: illegally copying and selling programs

-      Intentionally: attempting to spread viruses

25.         What are the main advantages of a computer?

-      The main advantages of a computer:

26.         What is a client/ server system?

-      The most common network arrangement is known as a client/server system.Servers are the main computers that provide a service on the network. Clients are the other computers that use the services.

27.         Why shouldn’t we use words in the dictionary or common name as passwords?

-      Because some hacker can use special computer program which automatically try all the words and combination words in a computerized dictionary to try to discover or crack other users’ password.

28.         What do we have to do in order to keep an email secret when you send it away?

-      => In order to keep an email secret when you send it away, we have to encode it with some form of encryption.

29.         What does the Windows NT’s provide ?

-      => Windows NT provides robust security features and a suite of security management tools that you can use to protect system data and control access to system resources.

30.         What are the advantages and disadvantage of security  strategies?

-      =>Advantage of security strategies:

-      The computer security strategies held to protect your data and source. Effective security strategies can prevent user from illegally accessing your data and also held novice user to avoid damaging the system or its data accidentally

-          Disadvantage of security strategies:

-      Security strategies is never finished and should be revised and tested periodically when configurations and other conditions and circumstances were changed

31.         Why can we say Window NT’s security features are flexible and extremely reliable?

-      => Because users can choose among a number of security models, tailoring Windows NT to the needs of their organization. As with many computer operating system Windows NT’s security is designed around the needs of users and user groups.