3i Infotech Placement: Sample Questions 6 - 7 of 1245

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Question 6

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Write in Short

Short Answer▾

What is attenuation?

Explanation

  • Degeneration of a signal over distance on a network cable is called attenuation (physical characteristic of the medium like cable) .
  • Attenuation refers to reduction in the strength of a signal.
  • Historically measured in dB but it can also be measured as voltage.
  • Applies to both hard-wired and wireless transmissions.

Different types of attenuation include:

  • Deliberate attenuation occurs where a volume control is used to lower the sound level on electronics.
  • Automatic attenuation is a common feature of televisions and other audio equipment to prevent sound distortion by automatic level sensing.
  • Environmental attenuation relates to signal power loss due to the transmission medium.

Question 7

Edit

Describe in Detail

Essay▾

Brief about the directory representation in UNIX.

Explanation

  • A UNIX directory is a file containing a correspondence between filenames and inodes.
  • A directory is a special file, it is maintained by the kernel- Only kernel modifies directory, but processes can read directories.
  • The contents of a directory are a list of filename and inode number pairs.
  • Kernel makes two entries when new directories are created

‘.’

  • The directory itself.

‘. .’

  • Parent directory.
Kernel Makes Two Entries

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