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Define Scanner and its types Points : define scanner and its types, flat bed scanner, handy scanner, sheet-feed scanner Scanner A scanner converts graphic and pictorial data to digital (binary) from which can be directly feed and stored in computer. The scanners are capable of digitizing not only shape and size of drawings but also varying intensities on a gray-to-black. They are used to scan more complex pictures and photographs. Now a days color scanner are also available. There are three types of scanners. Flat bed Scanner Handy Scanner Sheet-Feed Scanner Flat Bed Scanner: In case of a flatbed scanner, the drawing is fixed over a rectangular flatbed table. A mechanism is now moved over the surface of drawing which scans it and produces signals for the computer. Handy Scanner: The handy scanner is very small in size. The picture is placed on a flat surface and the scanner is moved downward by hand onto that picture to start scanning. Sheet-Feed Scanner: A scanner that feeds e

Short Note Points : short note on mouse, trackball, joystick, lightpen, microphone and digital camera Mouse: Mouse is also a primary input device but lacks the ability to easily transmit it textual information. It is also called pointing device that is used to move a pointer on the computer screen in order to point to a place on a display screen and to select one or more actions to be taken from the position. Trackball: A trackball is a pointing device that look like upside-down mouse. The function of trackball is same as of mouse, but you do not have to roll it over a flat surface. You use a trackball by rolling the ball with your palm or fingers in the direction you want the pointer to go. There are usually one to three buttons next to the ball, which are used just like mouse buttons. Joystick: A joystick is used only to play computer games. It is an input device, which controls the movement of a certain object is controlled by this handle, as well as the object can be jumped (i

Keyboard and divisions of keyboard Points : keyboard and divisions of keyboard, division of keyboard, alphanumeric keypad, numeric keyboard, function keypad, screen navigation, or cursor movement keys, modifier keys Keyboard In most computers, a Key board is the primary text input device. It consists of a set of keys for computer input, which uses the same key arrangement as the mechanical and electronic typewriter keyboards that produced the computer, but with a few extra keys for computer commands and usually with the addition of a numeric keypad. The standard arrangement of alphabetic keys is known as the QWERTY (pronounced KWEHR-TEE) keyboard. The name is derived from the arrangement of five keys at the left of the upper first row of alphabetic key. A standard key build includes about 100 keys and each key sends a different signals to the CPU. Keyboards for personal computers come in many different styles chat differ in size, number of keys and shape. Division of Keyboard

Bit, Byte and Nibble Points : Define terms bit a byte and nibble Bit: The abbreviation of bit is binary digit which is non - addressable unit of memory. It is represented in terms of 0 and 1 or On/Off respectively. Byte: The combination or group of 8 bits is called a Byte. A byte is the smallest addressable location of memory that can hold one character, the character may be an alphabet (A to Z or a to z) a numeral (0 to 9) or special symbol (such as ?, $, &, !, #). Nibble: A group of four bits is called Nibble. I Nibble = 4 bits or I nibble = 1/2 byte

Define the following terms Points : define the following terms, memory word, memory address, mhz, mips, memory access time, flops, cycle time, viruses of the computer i. Memory Word ii. Memory Address iii. MHz iv. MIPS v. Memory Access Time vi. FLOPS vii. Cycle Time viii. Viruses of the computer i. Memory Word: Memory word is defined as the number of bits or byte that is microprocessor can manipulate as a unit. The length of a word varies by computer. It depends upon the data bus capacity of a computer. ii. Memory Address: Memory addresses is the location or address by which the data is located or addressed (accessed). iii. MHz: Mega Hertz (MHZ) is a unit in which clock speed of a computer is measured, which indicates how fast a computer process information, usually 1MHZ = 1 millions cycles per second iv. MIPS: MIPS stands for Million of Instruction Per Second. it is the unit in which the processing speed of a computer is expressed i.e. how many instructions per second a comput

Function of ALU (Arithmetic Logic Unit in Computer) Points : function of alu (arithmetic logic unit in computer) The ALU (Arithmetic Logic Unit): When the control unit encounters and instruction that involves arithmetic or logic operations, it passes control to the second component of CPU, the arithmetic/Logic unit (ALU). Arithmetic operations are as you might except, the fundamental math operations like addition, subtraction, multiplication and division. Logical operations consist of comparisons i.e. two pieces of data are compared to see whether one is equal to (=), less than (<), or greater than (>) the other. They are also used combinations, such as “greater than or equal to”. The ALU also uses specialized storage areas called register in which data is held while operations are performed on it.