Showing posts with label System. Show all posts
Showing posts with label System. Show all posts

Sunday, March 25, 2012

Computer Based -

1. All of the following are examples of real security and privacy risks EXCEPT:
A. hackers.
B. spam.
C. viruses.
D. identity theft.
Answer: B

2. A process known as ____________ is used by large retailers to study trends.
A. data mining
B. data selection
C. POS
D. data conversion
Answer: A

3. ____________terminals (formerly known as cash registers) are often connected to complex inventory and sales computer systems.
A. Data
B. Point-of-sale (POS)
C. Sales
D. Query
Answer: B

4. A(n) ____________ system is a small, wireless handheld computer that scans an item’s tag and pulls up the current price (and any special offers) as you shop.
A. PSS
B. POS
C. inventory
D. data mining
Answer: A

5. The ability to recover and read deleted or damaged files from a criminal’s computer is an example of a law enforcement specialty called:
A. robotics.
B. simulation.
C. computer forensics.
D. animation.
Answer: C

6. Which of the following is NOT one of the four major data processing functions of a computer?
A. gathering data
B. processing data into information
C. analyzing the data or information
D. storing the data or information
Answer: C

7. ____________ tags, when placed on an animal, can be used to record and track in a database all of the animal’s movements.
A. POS
B. RFID
C. PPS
D. GPS
Answer: B

8. Surgeons can perform delicate operations by manipulating devices through computers instead of manually. This technology is known as:
A. robotics.
B. computer forensics.
C. simulation.
D. forecasting.
Answer: A

9. Technology no longer protected by copyright, available to everyone, is considered to be:
A. proprietary.
B. open.
C. experimental.
D. in the public domain.
Answer: A

10. ____________ is the study of molecules and structures whose size ranges from 1 to 100 nanometers.
A. Nanoscience
B. Microelectrodes
C. Computer forensics
D. Artificial intelligence
Answer: A

11. ____________ is the science that attempts to produce machines that display the same type of intelligence that humans do.
A. Nanoscience
B. Nanotechnology
C. Simulation
D. Artificial intelligence (AI)
Answer: D

12. ____________ is data that has been organized or presented in a meaningful fashion.
A. A process
B. Software
C. Storage
D. Information
Answer: D

13. The name for the way that computers manipulate data into information is called:
A. programming.
B. processing.
C. storing.
D. organizing.
Answer: B

14. Computers gather data, which means that they allow users to ____________ data.
A. present
B. input
C. output
D. store
Answer: B

15. After a picture has been taken with a digital camera and processed appropriately, the actual print of the picture is considered:
A. data.
B. output.
C. input.
D. the process.
Answer: B


16. Computers use the ____________ language to process data.
A. processing
B. kilobyte
C. binary
D. representational
Answer: C

17. Computers process data into information by working exclusively with:
A. multimedia.
B. words.
C. characters.
D. numbers.
Answer: D

18. In the binary language each letter of the alphabet, each number and each special character is made up of a unique combination of:
A. eight bytes.
B. eight kilobytes.
C. eight characters.
D. eight bits.
Answer: D

19. The term bit is short for:
A. megabyte.
B. binary language.
C. binary digit.
D. binary number.
Answer: C


20. A string of eight 0s and 1s is called a:
A. megabyte.
B. byte.
C. kilobyte.
D. gigabyte.
Answer: B

21. A ____________ is approximately one billion bytes.
A. kilobyte
B. bit
C. gigabyte
D. megabyte
Answer: C

22. A ____________ is approximately a million bytes.
A. gigabyte
B. kilobyte
C. megabyte
D. terabyte
Answer: C

23. ____________ is any part of the computer that you can physically touch.
A. Hardware
B. A device
C. A peripheral
D. An application
Answer: A


24. The components that process data are located in the:
A. input devices.
B. output devices.
C. system unit.
D. storage component.
Answer: C

25. All of the following are examples of input devices EXCEPT a:
A. scanner.
B. mouse.
C. keyboard.
D. printer.
Answer: D

26. Which of the following is an example of an input device?
A. scanner
B. speaker
C. CD
D. printer
Answer: A

27. All of the following are examples of storage devices EXCEPT:
A. hard disk drives.
B. printers.
C. floppy disk drives.
D. CD drives.
Answer: B

28. The ____________, also called the “brainsâ€
of the computer, is responsible for processing data.
A. motherboard
B. memory
C. RAM
D. central processing unit (CPU)
Answer: D


29. The CPU and memory are located on the:
A. expansion board.
B. motherboard.
C. storage device.
D. output device.
Answer: B

30. Word processing, spreadsheet, and photo-editing are examples of:
A. application software.
B. system software.
C. operating system software.
D. platform software.
Answer: A

31. ____________ is a set of computer programs used on a computer to help perform tasks.
A. An instruction
B. Software
C. Memory
D. A processor
Answer: B

32. System software is the set of programs that enables your computer’s hardware devices and ____________ software to work together.
A. management
B. processing
C. utility
D. application
Answer: D

33. The PC (personal computer) and the Apple Macintosh are examples of two different:
A. platforms.
B. applications.
C. programs.
D. storage devices.
Answer: A

34. Apple Macintoshes (Macs) and PCs use different ____________ to process data and different operating systems.
A. languages
B. methods
C. CPUs
D. storage devices
Answer: C

35. Servers are computers that provide resources to other computers connected to a:
A. network.
B. mainframe.
C. supercomputer.
D. client.
Answer: A

36. Smaller and less expensive PC-based servers are replacing ____________ in many businesses.
A. supercomputers
B. clients
C. laptops
D. mainframes
Answer: D


37. ____________ are specially designed computers that perform complex calculations extremely rapidly.
A. Servers
B. Supercomputers
C. Laptops
D. Mainframes
Answer: B

38. DSL is an example of a(n) ____________ connection.
A. network
B. wireless
C. slow
D. broadband
Answer: D

39. The difference between people with access to computers and the Internet and those without this access is known as the:
A. digital divide.
B. Internet divide.
C. Web divide.
D. broadband divide.
Answer: A

40. ____________ is the science revolving around the use of nanostructures to build devices on an extremely small scale.
A. Nanotechnology
B. Micro-technology
C. Computer forensics
D. Artificial intelligence
Answer: A

41. Which of the following is the correct order of the four major functions of a computer?
A. Process à Output à Input à Storage
B. Input à Outputà Process à Storage
C. Process à Storage à Input à Output
D. Input à Process à Output à Storage
Answer: D

42. ____________ bits equal one byte.
A. Eight
B. Two
C. One thousand
D. One million
Answer: A

43. The binary language consists of ____________ digit(s).
A. 8
B. 2
C. 1,000
D. 1
Answer: B

44. A byte can hold one ____________ of data.
A. bit
B. binary digit
C. character
D. kilobyte
Answer: C

45. ____________ controls the way in which the computer system functions and provides a means by which users can interact with the computer.
A. The platform
B. The operating system
C. Application software
D. The motherboard
Answer: B

46. The operating system is the most common type of ____________ software.
A. communication
B. application
C. system
D. word-processing software
Answer: C

47. ____________ are specially designed computer chips that reside inside other devices, such as your car or your electronic thermostat.
A. Servers
B. Embedded computers
C. Robotic computers
D. Mainframes
Answer: B

48. The steps and tasks needed to process data, such as responses to questions or clicking an icon, are called:
A. instructions.
B. the operating system.
C. application software.
D. the system unit.
Answer: A

49. The two broad categories of software are:
A. word processing and spreadsheet.
B. transaction and application.
C. Windows and Mac OS.
D. system and application.
Answer: D

50. The metal or plastic case that holds all the physical parts of the computer is the:
A. system unit.
B. CPU.
C. mainframe.
D. platform.
Answer: A


Fill in the Blank:

51. Between PCs and Macs, the ____________ is the platform of choice for graphic design and animation.
Answer: Mac

52. The ____________ is the program that manages the hardware of the computer system, including the CPU, memory, storage devices, and input/output devices.
Answer: operating system

53. The type of operating system software you use depends on your computer’s ____________.
Answer: platform

54. ____________software helps you carry out tasks, such as typing a document or creating a spreadsheet.
Answer: Application

55. ____________are the fastest and most expensive computers.
Answer: Supercomputers

56. A ____________ is approximately 1,000 bytes.
Answer: kilobyte

57. Input devices are used to provide the steps and tasks the computer needs to process data, and these steps and tasks are called ____________.
Answer: instructions

58. A computer gathers data, processes it, outputs the data or information, and ____________ the data or information.
Answer: stores

59. The binary language consists of two digits: ____________ and ____________.
Answer: 0 and 1

60. A string of ____________ 0s and 1s is called a byte.
Answer: eight (8)

61. The devices you use to enter data into a computer system are known as ____________ devices.
Answer: input

62. The devices on a computer system that let you see the processed information are known as ____________ devices.
Answer: output

63. ____________ is the set of computer instructions or programs that enables the hardware to perform different tasks.
Answer: Software

64. When you connect to the ____________, your computer is communicating with a server at your Internet service provider (ISP).
Answer: Internet

65. ____________ are computers that excel at executing many different computer programs at the same time.
Answer: Mainframes

66. ____________is the application of computer systems and techniques to gather legal evidence.
Answer: Computer forensics

67. ____________ is the science that attempts to create machines that will emulate the human thought process.
Answer: Artificial intelligence (AI)

68. Macintosh computers use the Macintosh operating system (Mac OS), whereas PCs generally run ____________ as an operating system.
Answer: Microsoft Windows

69. A process known as ____________ tracks trends and allows retailers to respond to consumer buying patterns.
Answer: data mining

70. Hard disk drives and CD drives are examples of ____________ devices.
Answer: storage

71. You would use ____________ software to create spreadsheets, type documents, and edit photos.
Answer: application

72. ____________ are computers that support hundreds or thousands of users simultaneously.
Answer: Mainframes

73. ____________ is the term given to the act of stealing someone’s identity and ruining their credit rating.
Answer: Identity theft

74. Surgeons are using ____________ to guide robots to perform delicate surgery.
Answer: computers

75. Patient ____________ are life-sized mannequins that have a pulse and a heartbeat and respond to procedures just like humans.
Answer: simulators


True and False

76. Currently, the performance of tasks by robots is based on preprogrammed algorithms.
Answer: True

77. Data can be a number, a word, a picture, or a sound.
Answer: True

78. Strictly defined, a computer is a data processing device.
Answer: True

79. The discrepancy between the “havesâ€
and “have-nots†with regard to computer technology is commonly referred to as the digital society.
Answer: False (digital divide)

80. One of the benefits of becoming computer fluent is being a savvy computer user and consumer and knowing how to avoid viruses, the programs that pose threats to computer security.
Answer: True

81. Trend-spotting programs, developed for business, have been used to predict criminal activity.
Answer: True

82. Employers do not have the right to monitor e-mail and network traffic on employee systems used at work.
Answer: False

83. Clicking on an icon with the mouse is a form of giving an instruction to the computer.
Answer: True

84. Output devices store instructions or data that the CPU processes.
Answer: False (memory)

85. The CPU and memory are located on a special circuit board in the system unit called the motherboard.
Answer: True

86. Nanostructures represent the smallest human-made structures that can be built.
Answer: True


87. The main difference between a supercomputer and a mainframe is that supercomputers are designed to execute a few programs as quickly as possible, whereas mainframes are designed to handle many programs running at the same time (but at a slower pace).
Answer: True

88. Being computer fluent means that you should be able to build a computer yourself.
Answer: False

89. Embedded computers are self-contained computer devices that have their own programming and do not receive input.
Answer: True

90. A Web browser is a special device that is installed in your computer that allows it to communicate with other devices on a network.
Answer: False (network adapter)

91. With a wireless network, it is easier to relocate devices.
Answer: True

92. The most common type of memory that the computer uses to process data is ROM.
Answer: False (RAM)

Matching:
93. Match the following terms with their approximate size:
I. kilobyte A. one million bytes
II. byte B. eight bits
III. gigabyte C. one thousand bytes
IV. megabyte D. one billion bytes
V. terabyte E. one trillion bytes
Answer: C, B, D, A, E

94. Match the following terms with their meanings:
I. printer A. storage device
II. scanner B. output device
III. RAM C. input device
IV. CPU D. a type of memory
V. CD drive E. processor
Answer: B, C, D, E, A

95. Match the following terms with their meanings:
I. mainframe A. the most expensive computers that perform complex calculations extremely rapidly
II. supercomputer B. a computer that provides resources to other computers connected to a network
III. embedded computer C. a large, expensive computer that supports hundreds or thousands of users simultaneously
IV. PDA D. a self-contained computer device that usually performs preprogrammed functions such as temperature control
V. server E. a small mobile computing device
Answer: C, A, D, E, B

96. Match the following terms with their meanings:
I. software A. transforming data into information
II. hardware B. data that has been organized or presented in a meaningful fashion
III. operating system C. any part of the computer that you can physically touch
IV. processing D. a set of computer programs that enables hardware to perform different tasks
V. information E. the most common type of system software, it controls the way in which the computer system functions
Answer: D, C, E, A, B

97. Match the following terms with their meanings:
I. system software A. the set of programs that enables computer hardware devices and application software to work together
II. application software B. the kind of operating system software you will use depends on this
III. platform C. operating system software generally used on PCs
IV. Microsoft Windows D. a set of programs used to accomplish a specific task
V. Mac OS E. operating system software used on the Apple Macintosh
Answer: A, D, B, C, E

98. Match the following terms with their meanings:
I. data A. the main circuit board in the system unit
II. memory B. the representation of a fact or idea (unprocessed information)
III. output C. processed data or information
IV. storage D. holds instructions or data that the CPU processes
V. motherboard E. data or information that can be accessed again
Answer: B, D, C, E, A

99. Match the following terms with their meanings:
I. bit A. the science revolving around the use of nanostructures to build devices on an extremely small scale
II. binary language B. the case that contains the system components
III. instructions C. consists of 0s and 1s
IV. system unit D. short for binary digit
V. nanotechnology E. steps and tasks necessary to process data into usable information
Answer: D, C, E, B, A


100. Match the following fields to the related computer technology:
I. medicine A. Internet research and virtual tours
II. business B. data mining
III. law enforcement C. robotics and simulation
IV. education D. computer forensics
V. archeology E. digital recreations of ruins
Answer: C, B, D, A, E

Saturday, March 3, 2012

HTML-

 The evolution of the latest version of HTML known as HTML5, a set of capabilities that gives web designers and developers the ability to create the next generation of great online applications. Take the HTML5 <video> tag, for example. Video wasn't a major (or, really, any) part of the early web...

Other cool HTML5 features include offline capabilities that let users interact with web apps even when they don't have an internet connection, as well as drag-and-drop capabilities. In Gmail, for instance, easy drag-and-drop allows users to instantly attach a file to an email message by simply dragging the file from the user's desktop computer into the browser window.

HTML5, like the web itself, is in perpetualevolution, based on users' needs and developers' imaginations. As an open standard, HTML5 embodies some of the best aspects of the web: it works everywhere, and on any device with a modern browser. But just as you can only watch HDTV broadcasts on an HD-compatible television, you need to use an up-to-date, HTML5-compatible browser in order to enjoy sites and apps that take advantage of HTML5's features. Thankfully, as an Internet user, you have lots of choice when it comes to web browsers — and unlike TVs, web browsers can be downloaded for free.

Monday, February 20, 2012

Cloud Computing-Technovation

Cloud Computing is Internet-based computing, whereby shared resources, software, and information are provided to computers  and other devices on demand, like the electricity grid.It allows consumers and businesses to use applications without installation and access their personal files at any computer with internet access & also for much more efficient computing by centralizing storage, memory, processing and bandwidth.
It is a model for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction.
Cloud computing works on a client-server basis, using web browser protocols. The cloud provides server-based applications and all data services to the user, with output displayed on the client device. If the user wishes to create a document using a word processor, for example, the cloud provides a suitable application running on the server which displays work done by the user on the client web browser display. Memory allocated to the client system’s web browser is used to make the application data appear on the client system display, but all computations and changes are recorded by the server, and final results including files created or altered are permanently stored on the cloud servers. Performance of the cloud application is dependent upon the network access, speed and reliability as well as the processing speed of the client device.
Cloud computing is a natural evolution of the widespread adoption of virtualization, Service-oriented architecture and utility computing. Details are abstracted from consumers,who no longer have need for expertise in, or control over, the technology infrastructure”in the cloud” that supports them. Cloud computing describes a new supplement, consumption, and delivery model for IT services based on the Internet, and it typically involves over-the-Internet provision of dynamically scalable and often virtualized resources.

Sunday, January 15, 2012

Technical interview-questions-and-answers


1. How are devices represented in UNIX?
All devices are represented by files called special files that are located in /dev directory. Thus, device files and other files are named and accessed in the same way. A 'regular file' is just an ordinary data file in the disk. A 'block special file' represents a device with characteristics similar to a disk (data transfer in terms of blocks). A 'character special file' represents a device with characteristics similar to a keyboard (data transfer is by stream of bits in sequential order).
2. What is 'inode'?
All UNIX files have its description stored in a structure called 'inode'. The inode contains info about the file-size, its location, time of last access, time of last modification, permission and so on. Directories are also represented as files and have an associated inode. In addition to descriptions about the file, the inode contains pointers to the data blocks of the file. If the file is large, inode has indirect pointer to a block of pointers to additional data blocks (this further aggregates for larger files). A block is typically 8k.
Inode consists of the following fields:
  1. File owner identifier
  2. File type
  3. File access permissions
  4. File access times
  5. Number of links
  6. File size
  7. Location of the file data
3. Brief about the directory representation in UNIX.
A Unix directory is a file containing a correspondence between filenames and inodes. A directory is a special file that the kernel maintains. Only kernel modifies directories, but processes can read directories. The contents of a directory are a list of filename and inode number pairs. When new directories are created, kernel makes two entries named '.' (refers to the directory itself) and '..' (refers to parent directory). System call for creating directory is mkdir (pathname, mode).
4. What are the Unix system calls for I/O?
  1. open(pathname,flag,mode) - open file
  2. creat(pathname,mode) - create file
  3. close(filedes) - close an open file
  4. read(filedes,buffer,bytes) - read data from an open file
  5. write(filedes,buffer,bytes) - write data to an open file
  6. lseek(filedes,offset,from) - position an open file
  7. dup(filedes) - duplicate an existing file descriptor
  8. dup2(oldfd,newfd) - duplicate to a desired file descriptor
  9. fcntl(filedes,cmd,arg) - change properties of an open file
  10. ioctl(filedes,request,arg) - change the behaviour of an open file
  11. The difference between fcntl anf ioctl is that the former is intended for any open file, while the latter is for device-specific operations.
5. How do you change File Access Permissions?
Every file has following attributes:
  1. owner's user ID ( 16 bit integer )
  2. owner's group ID ( 16 bit integer )
  3. File access mode word
(r w x) - (r w x) - (r w x)
(user permission) - (group permission) - (others permission)
To change the access mode, we use chmod(filename,mode).
Example 1:
To change mode of myfile to 'rw-rw-r--' (ie. read, write permission for user - read,write permission for group - only read permission for others) we give the args as:

chmod(myfile,0664) .

Each operation is represented by discrete values
'r' is 4
'w' is 2
'x' is 1
Therefore, for 'rw' the value is 6(4+2).

Example 2:
To change mode of myfile to 'rwxr--r--' we give the args as:

chmod(myfile,0744).
6. What are links and symbolic links in UNIX file system?
A link is a second name (not a file) for a file. Links can be used to assign more than one name to a file, but cannot be used to assign a directory more than one name or link filenames on different computers.
Symbolic link 'is' a file that only contains the name of another file.Operation on the symbolic link is directed to the file pointed by the it.Both the limitations of links are eliminated in symbolic links.
Commands for linking files are:
Link "ln filename1 filename2"
Symbolic link "ln -s filename1 filename2"
7. What is a FIFO?
FIFO are otherwise called as 'named pipes'. FIFO (first-in-first-out) is a special file which is said to be data transient. Once data is read from named pipe, it cannot be read again. Also, data can be read only in the order written. It is used in interprocess communication where a process writes to one end of the pipe (producer) and the other reads from the other end (consumer).
8. How do you create special files like named pipes and device files?
The system call mknod creates special files in the following sequence.
  1. kernel assigns new inode,
  2. sets the file type to indicate that the file is a pipe, directory or special file,
  3. If it is a device file, it makes the other entries like major, minor device numbers.
For example:
If the device is a disk, major device number refers to the disk controller and minor device number is the disk.
9. Discuss the mount and unmount system calls.
The privileged mount system call is used to attach a file system to a directory of another file system; the unmount system call detaches a file system. When you mount another file system on to your directory, you are essentially splicing one directory tree onto a branch in another directory tree. The first argument to mount call is the mount point, that is , a directory in the current file naming system. The second argument is the file system to mount to that point. When you insert a cdrom to your unix system's drive, the file system in the cdrom automatically mounts to "/dev/cdrom" in your system.
10. How does the inode map to data block of a file?
Inode has 13 block addresses. The first 10 are direct block addresses of the first 10 data blocks in the file. The 11th address points to a one-level index block. The 12th address points to a two-level (double in-direction) index block. The 13th address points to a three-level(triple in-direction)index block. This provides a very large maximum file size with efficient access to large files, but also small files are accessed directly in one disk read.
11. What is a shell?
A shell is an interactive user interface to an operating system services that allows an user to enter commands as character strings or through a graphical user interface. The shell converts them to system calls to the OS or forks off a process to execute the command. System call results and other information from the OS are presented to the user through an interactive interface. Commonly used shells are sh,csh,ks etc