TCS Papers: Sample Questions 462 - 463 of 502

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Question number: 462

» Basic CS » Operating System

Essay Question▾

Describe in Detail

Define the PBS

Explanation

  • PBS means Priority Based Scheduling.

  • Priority scheduling is a non-preemptive algorithm and one of the most common scheduling algorithms in batch systems.

  • Each process is assigned a priority. Process with highest priority is to be executed first and so on.

  • Processes with same priority are executed on first come first served basis.

  • Priority can be decided based on memory requirements, time requirements or any other resource requirement.

  • Multiple process with same priority are dealt using FCFS (First-Come-First-Serve).

Image of Priority based scheduling

Image of Priority Based Scheduling

Given the image is define the priority based scheduling process

Question number: 463

» Basic CS » Networks

Essay Question▾

Describe in Detail

What is CRC?

Explanation

  • The cyclic redundancy check (CRC) detects errors in digital data using hash function.

  • Used in digital networks and storage devices such as hard disk drives.

  • Invented by W. Wesley Peterson in 1961 and further developed by the CCITT (Comite Consultatif International Telegraphique et Telephonique).

  • Quite simple to implement in hardware and can be easily analyzed mathematically.

  • Based on binary division

  • Also called polynomial code checksum.

  • Given a k-bit frame or message, the transmitter generates an n-bit sequence, known as a frame check sequence (FCS), so that the resulting frame, consisting of (k + n) bits, is exactly divisible by some predetermined number.

  • The receiver then divides the incoming frame by the same number and, if there is no remainder, assumes that there was no error.

Image shows the CRC

Image Shows the CRC

Given the image is define the Cycle redundancy check

Image shows the CRC Example

Image Shows the CRC Example

Given the image is define the CRC example