Khans Academy

Data Communication and Computer Networks Q#1: List the properties of a good communication system. Explain any one.    Ans:    1. Delivery   2. Accuracy   3. Timelines   4. Jitter  Accuracy: The system must deliver the data accurately. Data that has been altered during transmission and left uncorrected is not useful.  Q#2: Why OSI model is broken up in layers?  Ans: The OSI model is conceptual. It is broken up into layers so a person can visualize network communications and steps a computer takes when it encapsulates data from the application to the medium.  Q#3: Explain the purpose of Standard Organization.  Ans: Standard Organization develops, coordinates, revises, amends and reissues technical standards. These standards are intended to address the requirements of a group of concerned devices. There are several organizations working on standardization of computing equipment. IEEE, IETF, ITU and ANSI are ...

Chapter#4  Control Structure Q#1: What is the purpose of “Default” statements in C++?  Ans: The purpose of the default in the switch case is to provide an option in case the conditions specified to trigger the execution of code within the other options does not occur so that the program will not crash.  Consider this portion of code with switch case statements. switch(expression) {  case “expression1”: /// Code body corresponding to case expression1 case “expression2″: /// Code body corresponding to case expression2  default: //This body is evaluated if none of the case statement are equivalent to the expression.  } Q#2: Can we use while loop in place of for loop? If yes, then how?  Ans: YES. But in most of the cases it’s advisable to use the loops appropriately.  For example, in the below give code, both the loops perform the exact same operation (finding sum of first n numbers) 1. FOR LOOP:  for(i=1 ; i<=n ; ++i)     ...