Perfect Computer Notes

What is Memory Management? One of the main functions of Operating systems is Memory Management. Memory Management may be defined as the process of managing the optimal use of main memory that is RAM (Random Access Memory). RAM is much faster than hard disk. So RAM is used to store data and instructions temporarily while they are being executed by CPU ( Central Processing Unit or PROCESSOR ). CPU can get data and instructions from RAM much faster that from hard disk. As we know CPU is a very very fast device. It may execute billions of instructions per second. CPU will have to wait for data and instruction from hard disk because getting data from hard disk is very slow. That is why RAM is used. So data and instructions needed for execution are brought into main memory that is RAM first. Now RAM provides data and instructions to CPU rapidly. What is Memory Management and virtual memory management Operating System allocates the required memory are in main memory to program

Why To Use Left Function in Microsoft Excel? The Left function is used to get first N characters from the given text string or the text contained in a cell. Syntax of LEFT Function in Excel LEFT(Text, Number_of_characters) For example, the function LEFT("Normal",3) will return Nor. Syntax of LEFT function with Cell Reference LEFT(CellReference, Number_of_characters) For example, let the cell A2 contains the text Humanity , the function LEFT(A2,5) will return Human . Similarly if Cll A12 contains "England" then Left(A12,5) will give "Engla" that is first five characters of contents of cell A12 from left side. How To Implement LEFT Function in Excel Uses of Excel Functions Left Right in Excel Worksheet    First of all place the cursor in an empty cell next to cell A2, to enter the function. Type = Type the function name LEFT Type the left parenthesis ( Type A2 from keyboard. Type , (that is Comma) Type 5 so that the first 5

What is MAX Function? Learn Practical Use of MAX Function and MIN Function in Excel Worksheets The MAX function is used to get the maximum number from different given numbers in Excel Worksheet. Syntax of MAX Function in Excel MAX(number1,number2,number3,...numberN) For example the function MAX(5,100,35) will return 100, since 100 is largest number of all 5, 100 and 35. Syntax of MAX Function using Cell References MAX(CellRef1:CellRef2) Where CellRef1 is the cell reference of the first cell and CellRef2 is the cell reference of the last cell in the given cell range in Excel Worksheet. What is MIN Function? The MIN function is used to get the minimum number from different given numbers in Excel Worksheet. Syntax of MIN Function in Excel MIN(number1,number2,number3,...numberN) For example the function MIN(5,100,35) will return 5, since 5 is the smallest number of all 5, 100 and 35. Syntax of MIN Function using Cell References MIN(CellRef1:CellRef2) Where Cel