TCS Papers: Sample Questions 272 - 274 of 502

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Question number: 272

» Languages » C & C Plus Plus

Short Answer Question▾

Write in Short

Why is it that not all header files are declared in every C program?

Explanation

  • The choice of declaring a header file at the top of each C program would depend on what commands or functions used in that program.

  • Since each header file contains different function definitions and prototype, only use those header files that contain the needed functions.

  • Declaring all header files in every program would increase the overall file size and load of the program, and is not a good programming style.

Question number: 273

» Basic CS » Operating System

Essay Question▾

Describe in Detail

Which method does one uses to enforce garbage collection in. NET?

Explanation

  • The System. GC. Collect () method forces garbage collection

  • Garbage collection occurs when one of the following conditions is true:

  • The system has low physical memory.

  • Memory used by allocated objects on the managed heap surpasses an acceptable threshold.

  • Threshold is continuously adjusted as the process runs.

  • The GC. Collect method is called primarily for unique situations and testing.

Question number: 274

» Basic CS » Networks

Essay Question▾

Describe in Detail

What Automatic Repeat Request (ARQ)?

Explanation

  • Automatic repeat request (ARQ) protocol does error control in data transmission.

  • When receiver detects an error, it automatically requests the transmitter to resend the packet. Process is repeated until the packet is error free or the error continues beyond a predetermined number of transmissions.

  • ARQ is sometimes used with Global System for Mobile (GSM) communication to guarantee data integrity.

  • Error control in the data link layer is often implemented simply: Any time an error is detected in an exchange, specified frames are retransmitted. This process is called automatic repeat request (ARQ).

  • Automatic Repeat Request (ARQ), also called Automatic Repeat Query, is an error-control protocol that automatically initiates a call to retransmit any data packet or frame after receiving flawed or incorrect data.

  • When the transmitting device fails to receive an acknowledgement signal to confirm the data has been received, it usually retransmits the data after a predefined timeout and repeats the process a predetermined number of times until the transmitting device receives the acknowledgement.

  • ARQs are often used to assure reliable transmissions over an unreliable service.

Image shows the ARQ

Image Shows the ARQ

Given the image is define the Automatic Repeat Request (ARQ)