SEE 2073(Supplementary)
Group A
1. Write the one function of monitor.
à Function of monitor is to display visual information that has been fed to it by a computer’s video card.
2. Name two groups of keys in keyboard with examples.
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· Function keys. Example: F1, F2, F3….F12
· Alphanumeric keys. Example: letters of the alphabet, mathematical symbols, numbers
3. Define cylinder.
à A set of tracks, all of the same diameter through each platter is called a cylinder.
4. Write any two devices used for cooling.
à Two devices used for cooling are:
· Heat sink
· Fan
5. Write the importance of backup in one point.
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6. What is the function of hard disk LED?
à The function of hard disk LED is to indicate whether the drive is active or not.
7. Name any two I/O ports.
à Two I/O ports are:
· USB (Universal Serial Bus) port
· HDMI (High Definition Multimedia Interface) port
· PS/2 port
· Serial port
· Parallel port
Group B
8. Write any two features of LCD monitors.
à Two features of LCD monitors are:
· LCD monitors can encounter dead pixels, which causes small black or other colored dots in the display.
· LCD monitors are much thinner
· LCD monitors have a slightly bigger viewable area than a CRT monitor.
9. Convert 25.2 GB to KB
à Here, 25.2 GB
= 25.2 x 106 B
=25.2 x106 x 10-3 KB
=25200 KB
10. Write any two software tools used to maintain PC.
à Software tools used to maintain the PC are;
· Antivirus software such as Norton antivirus
· Disk Defragmentation software
· PC cleaning software such as CCleaner.
· CPU and GPU temperature monitoring software such as HWMonitor.
11. Give the full form of DIMM and SIMM.
à The full form of DIMM is Dual In-line Memory Module and SIMM is Single In-line Memory Module.
12. Define the terms "North Bridge" and "south bridge".
à Northbridge is a chipset that communicates with the computer processor and controls interaction with memory, the Peripheral Component Interconnect (PCI) bus, Level 2 cache, and all Accelerated Graphics Port (AGP) activities
The Southbridge is an IC on the motherboard responsible for the hard drive controller and I/O controller
13. Name the type of cables used for DVD drive interfacing.
à The type of cables used for DVD drive interfacing are:
· PATA/ATA (Advanced Technology Attachment)/IDE(integrated drive electronics)
· SATA (Serial ATA)
· SCSI(Small computer system interface)
14. Write two ways to prevent computer from virus.
à Two ways to prevent computer virus are:
· Install and use software form reputed source only.
· Regularly update your OS.
· Be careful while opening email attachments form unknown people.
· Use trusted antivirus software.
· Don’t use unknown removable drive.
15. What is media rotation? Why is it important?*
à A backup rotation scheme is a system of backing up data to computer media (such as tapes) that minimizes, by re-use, the number of media used. The scheme determines how and when each piece of removable storage is used for a backup job and how long it is retained once it has backup data stored on it.
16. What type of data are considered for back up?
à Documents, media files, configuration files, machine images, operating systems, registry files etc. are considered for backup.
17. Differentiate between maintenance and repair.
à Maintenance are routine activities meant to prevent damage and prolong the life of computer whereas repair is the process of identifying, troubleshooting and resolving problems and issues in a faulty computer.
Repair is done only after equipment has failed but maintenance is done to prevent failure
18. How do you troubleshoot "hard disk not found" problem.
à I troubleshoot “hard disk not found” problem by following methods:
· Checking Hard disk Data Cable or Power Cable is plugged or not.
· Restoring BIOS setup default settings configuration.
19. What is Programmable read only memory (PROM)? Give one example.
à PROM or programmable ROM (programmable read-only memory) is a computer memory chip that can be programmed once after it is created. Example: computer BIOS in early computers
20. Define mouse. Write its use.
à A computer mouse is a pointing device that detects two-dimensional motion relative to a surface. Its uses are:
· To open or execute a program
· To select text or a file or select multiple files at once.
· To Drag-and-drop something
· To scroll
21. Write the steps to change the system time.
à Steps to change the system time:
i. Right-click on the time in the bottom-right of the screen and select Adjust Date/Time.
ii. A window will open. On the left side of the window select the Date & time tab. Then, under "Change date and time" click Change
iii. Enter the time and press Change.
iv. The system time has been updated.
Group C
22. What is startup problems? How do you solve it?*
à The issues that could prevent your computer from turning on are called startup problems. Some of these problems are power supply problems, Bios problems or OS problems.
I can solve them by implementing following methods:
· By checking SMPS
· By replacing the power supply
· By using start up repair tool
· Reinstalling the OS
· Listening to beep sound and responding to it
· By contacting the manufacturer.
23. How do you identify power problems? Explain.*
à I can say there might be the power problems if the computer shows following behavior:
· Computer turns on for some time then it suddenly turns off.
· Random black & blue screen crashes
· Random Computer Crashes and Restarts.
· Display Issues
· Freezing
· Smoke/Burning Smell
· Strange noises from the PC case
· Presence of Frequent Electric Shocks When You Touch the Metallic Parts of the Computer.
· The power supply fan spins, but there is no power to other devices
· PC won’t start, but the case fans spin.
· Overheating of PSU
24. Write short note on system care.
à Of course, as computer users, we should take care of our computers. Basic care and maintenance for your computer are very important. It prevents certain factors and issues from arising, affecting the PC performance. If you take good care of your computer, you can get rid of viruses, malware, and other threats in advance. We can follow following method for system care:
· Keep your software up-to-date: Your computer will prompt you if there are software updates. It is important that you keep your software up-to-date, including your operating system to fix bugs, glitches, and vulnerabilities of the previous version. They also strengthen the security of your computer. Some computers perform automatic updates.
· Install antivirus software: A computer virus is a primary threat to computer health. They damage not just certain programs and software in your computer, but your system as a whole. It is important that you keep these viruses from entering your computer. Install antivirus software that will detect, block, and eliminate all types of viruses. There are dozens of competitive antivirus software available on the internet.
· Avoid eating near computers: This is a must! Avoid eating near your computers, or better, do not eat while using your computer. Food crumbs or pieces may get into your keyboard and other parts of your computer which will attract ants, termites, and other insects. If this happens, the insects might destroy some internal parts on your computer.
· Get rid of unused programs: Make it a habit to declutter your PC. Get rid of old files and programs that you do not need anymore. This will lessen the burden of your PC from running them in the background. The best way to do this is to install and run a disk cleanup program that deletes temporary files and clean your registry.
· Activate the Firewall: Viruses can penetrate your computer systems through the internet. It is important to activate your firewall. A firewall acts as a gate or barrier that filters data from gaining unauthorized access to the computer system. Typically, computers have a built-in firewall. But if you want to strengthen security, install a third-party firewall that provides maximum internet protection.
· Invest in cooling pads: Another factor that affects PC performance is overheating. When you use your computers for a longer period of time, consider buying cooling pads. Cooling pads are external devices that prevent computers from overheating. Apart from cooling pads, you can use fans. But if you want it to be easy, avoid using your computers in an environment with extreme temperatures.
25. How does virus harm our computer? Classify virus with example.
à Viruses affect our computer by corrupting files, interrupting Internet traffic and taking over basic functions of your operating system. These behaviors can knock a system offline and cause crashes. Viruses can record keystrokes and screen data, and they may steal personal information and passwords to transmit back to the malware author. Particularly malicious viruses completely take over a computer and use it as a weapon against others. In some cases, viruses even have the ability to damage the BIOS, the low-level system programs hard coded into motherboards that are responsible for the most basic functions of a computer. Fortunately, these are relatively rare due to the fact that each motherboard manufacturer uses different standards for its programs.
The different types of virus with their infection mechanism and example are explained below:
· Boot Sector Virus: These programs attack the vulnerable boot program that is stored on every bootable floppy disk or hard disk. Since the boot program is executed every time a computer is started, a boot sector virus is extremely dangerous. Once the boot code on the drive is infected, the virus will be loaded into memory on every startup. From memory, the boot virus can spread to every disk that the system reads. A boot sector virus can cause a variety of boot or data retrieval problems. In some cases, data disappear from entire partitions. In other cases, the computer suddenly becomes unstable. Often the infected computer fails to start up or to find the hard drive. Also, error messages such as "Invalid system disk" may become prevalent. Boot sector are typically very difficult to remove as malicious code is executed before many security layers are executed, including antivirus software. Popular examples of the boot sector virus include: Elk Cloner, Brain, Stoned, Parity Boot Virus, Michelangelo, and Angelina.
· File infecting Virus: A file-infecting virus is one of the most common types of virus. These viruses directly attack and modify program files, which are usually .EXE or COM files. When the program is run, the virus executes and does whatever it wants to do. Usually it loads itself into memory and waits for a trigger to find and infect other program files. These viruses are commonly spread through infected floppy disks, over networks, and over the Internet.Win32.Sality.BK, Jerusalem, Cascade, Sunday are some example of file-infecting virus.
· Macro Virus: Macro virus is a computer virus written in the same macro language as the software it infects — common victims include Microsoft Excel and Word. Because they target software rather than systems, macro viruses can infect any operating system. Well known example are Concept virus and Melissa Virus.
26. Explain the working principle of CD.
à A CD is usually around 12 centimeters (4.5 inches) in diameter and consists of thin circular layers attached one on top of another.
There are the several layers in CD. The bottom layer is a polycarbonate layer where data is encoded by using tiny bumps on the surface. Above this layer is a reflective layer typically made of aluminum (gold is also used, although quite rarely). Above the reflective layer is a protective layer of lacquer and plastic, which shields the layers below. The artwork or label is printed on top layer of the CD via offset printing or screen printing. CDs store information digitally, i.e., with the help of millions of 1s and 0s. Data on a CD is encoded with the help of a laser beam that etches tiny indentations (or bumps, if you will) on its surface. A bump, in CD terminology, is known as a pit and represents the number 0. Similarly, the lack of a bump (known as land) represents the number 1. Hence, a laser beam can encode the required data into a compact disc using pits and lands (0 and 1, respectively).
Now that you know how a CD is encoded with data. Let’s look at how a CD player actually reads this stored data.
There are two main components in a CD player that help read a CD: a tiny laser beam known as a semiconductor diode laser and an electronic light detector, basically a tiny photoelectric cell. When you turn on the CD player, an electric motor in the player rotates the CD at a very high speed while reading the outer edge at 200 RPM, and when reading the inner edge, it rotates at 500 rpm. The laser beam source inside the player switches on and scans along a track from the center of the disc to the outer rim. It focuses a 780 nm wavelength (near-infrared) beam through the underside of the compact disc. When the beam falls on land (1), it reflects straight back, but it scatters when the beam falls on a pit (0). When the photocell detects the reflected light, it recognizes that the laser must have hit land and, in turn, sends a signal to a circuit that generates the number 1. Likewise, when it does not detect light, it correctly determines a pit at this point so that the circuit generates the number 0. Thus, the photocell uses the intensity changes of the reflected beam to determine whether there is a 1 or a 0 on the disk.
The burning process of a CD is nothing but creating a pattern of pits and lands over the polycarbonate layer. But since the data must be accurately encoded on such a small scale, the burning process must be extremely précised. A CD burner is used to write (burn) the data on a CD. It incorporates a moving laser quite similar to a CD player which is known as ‘Write Laser’. The Write Laser which is more powerful than the ‘Read Laser’, has the capability to alter the surface of CD instead of just bouncing the laser light off. During burning process, as per the data (binary values) the Write Laser bounces the light beam over the CD surface and creates a series of pits on it.
27. Draw the structure of CRT monitor and explain*
à It is a type of vacuum tube which displays images when the electron beam through electron guns strikes on the phosphorescent surface.
The electron gun emits electrons and forms them into a beam by the help of a heater, cathode, grid, pre-accelerating, accelerating and focusing anode. After exiting from the electron gun, the beam passes through the pairs of electrostatic deflection plate. These plates deflected the beams when the voltage applied across it. The one pair of plate moves the beam upward or downward and the second pair of plate moves the beam from one side to another. The horizontal and vertical movement of the electron are independent of each other, and hence the electron beam positioned anywhere on the screen
28. Explain switching mode power supply with its block diagram.*(very difficult)
à A switched-mode power supply (switching-mode power supply, switch-mode power supply, switched power supply, SMPS, or switcher) is an electronic power supply that incorporates a switching regulator to convert electrical power efficiently.
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