DCA Notes In Hindi PDF Computer Fundamental (TOP 10) Imp Questions 2023 Unit 2
DCA Notes In Hindi PDF Computer Fundamental (TOP 10) Imp Questions 2023 Unit 2 PGDCA 1st sem notes in hindi pdf
PGDCA fundamental notes in hindi
(i) MICR
(ii) OCR
(iii) OMR
(iv) FIG
(v) Touch Screen
(vi) Digital Cameras
(vii) Digitizer Tablet
Answer-(i) MICR (Magnetic Ink Character Recognition) – MICR is more used in banking. They are used to check large number of checks in the bank. In MICR technology, characters are printed on the check by special magnetic ink. MICR reader reads the character printed on the check by sensing the magnetic coil. In this, no light is cast on the characters by optical method.
(ii) OCR (Optical Character Recognition) — In this, preprinted characters are identified with OCR standard characters. OCR fonts (type or currency letters of the same type) are stored in computers, which are called OCR standards. Of these, OCR A and OCR-B are more popular.
The OCR reader reads characters printed from typewriters, characters from cash registers and characters from credit cards. The OCR reader scans the characters using a photo-electric device. And converts the reflected light data into binary data (1 and 0) and inputs it into the computer. These are recognized by the computer from the pre-saved standard OCR font. Typical OCR speeds are 1,500 to 3,000 characters per second. OCR is mostly used in Billing System.
(iii) OMR (Optical Mark Reader) – OMR is used to check the answer sheet of an examination. In these examinations, there are optional questions in the question paper and the student has to choose one answer from four or five options and fill it in his answer sheet.
In this the light is shone on the marked paper and the reflected light is checked, where the mark will be present, the intensity of the reflected light will be less from that part of the paper. This technique checks only the boxes marked at the designated places on the printed card or form and the boxes filled with pencils. The speed of OMR is slow. Its data transfer rate is 200 to 250 pages per minute.
(iv) OBR (Optical Bar-code Reader) - The main function of OBR is to scan the vertical bars which are fixed for different data. It is used to read Bars on the back of books and Bars printed on the back of various products. Bar code keeps the cost of the product and other information related to it compiled. There are two models in BCR - Flatbed & Handheld.
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(v) Touch Screen — Touch screen is used nowadays in ATM Machines in Bank, Catalog File of LibraryTo find and it happens in Mobile Phones etc. All touch terminals have a sensitive screen which is made up of many points, which are called touch points. Apart from this sensitive screen, there would also be a keyboard with the terminal. which allows the input of data. When the user touches the screen with his fingers, he makes input by touching the touch point. This type of input is generally useful for people who have no knowledge about computers.
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(vi) Digital Camera — Pictures can be entered into the computer with the help of a digital camera. A digital camera captures a picture, stores it and sends it to the computer in digital form. These images are later stored as digital files.Digital cameras can also be used for two-to-one conversations over the Internet. If cameras are installed on both sides, then each other's face is also visible while talking to each other.
(vii) Digitizer Tablet – Digitizer tablet is also called graphic tablet. It is a drawing surface, with a pen or mouse on it. There is a mesh of thin wires on the drawing surface. On which the signals go to the computer as soon as the pen is used. There is a scanning head on top of it which is called Puck. This scanning head is used to get the desired position and the button is given when the position is achieved. Graphic tablets are used to create specific designs.
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Describe the properties of monitors.
Answer- Following are the main features of the monitor-
(a) Resolution - This is an important characteristic of the monitor. Resolution refers to the clarity of the picture displayed on the monitor. In most display devices, the image is made up of tiny dots on the screen. These little dots are called pixels. The word pixel is an abbreviation for Picture Elements. The number of pixels per unit area on the screen represents the resolution. The more pixels on the screen, the higher the resolution of the screen and the clearer the picture will appear. 640 by 480 resolution means that the screen is made up of 640 dot columns and 480 dot rows. Text or characters are formed from the dot-matrix on the screen. Normally 25 rows of 65 characters can be displayed on a screen.
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(b) Dot Pitch Through dot pitch, we get to know that there is a vertical difference between each pixel. Dot pitch is measured in millimeters. Dot pitch is also called Phosphor pitch. This clarifies the quality of the display monitor. The dot pitch range of a cooler monitor is usually from 0.15 mm to 0.30 mm.
(c) Interlaced or Non-Interlaced - Interlacing is a technique which effectively increases the display resolution of the monitor and increases the quality. With an interlacing monitor the electron gun only drew half the line, because the interlacing monitor only refreshed half the line at a time and this monitor displayed more than two lines per refresh cycle. Interlacing shows the same resolution as non-interlacing. But its carrying is less. Interlacing Animation & Visuals
Not suitable for program. The work is the same for both the monitors, but the non-interlacing monitor is better. (d) Bit Mapping - Initially display devices were only Character Addressable which used to display only text. Each character sent to the screen was a block (group) of the same size and a fixed number of pixels.
As the demand for graphics display devices increased, monitor manufacturers developed multi-purpose display devices that could display both text and graphics. Bit mapping technology is used for graphics output display. In this technique, each pixel of the bit rope graphics can be drawn on the screen by the operator. (e) Text and graphics- When the output is received in the form of letters, symbols and numbers, it is called text output.While the form of picture photograph or drawing is called Graphics. Most display devices today are capable of displaying both text and graphics output. (f) Size—There are two ways to know the details of the display on the monitor, Aspect Ratio and Screen Size. conventional monitors
The aspect ratio of the screen is 4:3. This means that the ratio of the width and height of the screen is 4 and 3.
Is. The Aspect Ratio in Wide Screen LCD Monitor is usually 16:9. In special circumstances it can be 16:10 or even 15:9.
it happens.
All types of displays including projection surfaces are commonly referred to as screens. Screen size is usually measured diagonally in inches from one corner to the other. There is a significant difference in measuring the screen size of CRT Monitors and LCD Monitors. Screen Size in CRT Monitors is measured from the Outer Edges including the Display Casing, while in LCD Monitors the Screen Size is measured from the Inside Beveled Edges. Because of this difference in measuring screen size, the display of a 17-inch LCD monitor is almost equal to the display of a 19-inch CRT monitor.
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What is line printer? Write its procedure. What is Line Printer? Write its working.
Answer: Line printers print one line of output at a time. Most line printers use Impact printing technology. Their printing speed is 300/- to 3,000 lines per minute. These are used for large tasks in mini computers and mainframe computers. Following are the line printers-
(1) Drum Printer - The Im printer consists of a fast rotating drum on which the characters are raised on the surface. There is a group of all letters on a band, there are many such bands on the drum. Due to which characters can be printed at every position of the line on the paper. Im spins fast and prints a line in one rotation. A high-speed hammer strikes the paper against the appropriate character in each band and a line is printed when one rotation is completed.
(2) Chain Printer This printer has a chain which rotates very fast. The chain consists of characters. Each link has a character font. Hammers are engaged at each print position. The hammer strikes the paper and the character to print one line at a time.
What is the difference between hard copy output and soft copy output? What is the difference between Hard Copy Output and Soft Copy Output?
Answer - The output devices of the computer can usually present the results in the following two states -
(1) Hard Copy - The output printed on a paper or microfilm is called Hard Copy. It is permanent. Mostly printers are used for hardcopy.
(2) Soft Copy – When the result (output) obtained from the system unit (CPU) is displayed on the monitor, then this result is called soft copy. It is temporary.While the form of picture photograph or drawing is called Graphics. Most display devices today are capable of displaying both text and graphics output. (f) Size—There are two ways to know the details of the display on the monitor, Aspect Ratio and Screen Size. conventional monitors
The aspect ratio of the screen is 4:3. This means that the ratio of the width and height of the screen is 4 and 3.
Is. The Aspect Ratio in Wide Screen LCD Monitor is usually 16:9. In special circumstances it can be 16:10 or even 15:9.
it happens.
All types of displays including projection surfaces are commonly referred to as screens. Screen size is usually measured diagonally in inches from one corner to the other. There is a significant difference in measuring the screen size of CRT Monitors and LCD Monitors. Screen Size in CRT Monitors is measured from the Outer Edges including the Display Casing, while in LCD Monitors the Screen Size is measured from the Inside Beveled Edges. Because of this difference in measuring screen size, the display of a 17-inch LCD monitor is almost equal to the display of a 19-inch CRT monitor.
Describe the following-
Answer- (i) Scanner—Scanner is an input device which is used to input information directly into the computer. The scanner reads the text, photo and other material printed on a paper and transfers it to the computer as an image. It converts text and any other material written on paper into digital form. The biggest advantage of using a scanner is that it does not require the user to type information. There are two types of scanners-
(1) MICR (Magnetic Ink Character Recognition) - MICR is more used in banking. They are used to check large number of checks in the bank. In MICR technology, characters are printed on the check by special magnetic ink. MICR reader reads the character printed on the check by sensing the magnetic coil. In this, no light is cast on the characters by optical method.
(2) Optical Scanners- In this, light is put on the characters by optical method. Examples of this are OCR, OMR and OBR.
OCR (Optical Character Recognition) - In this, preprinted characters (Preprinter Characters) are identified with OCR standard characters. OCR fonts (type or currency letters of the same type) are stored in the computer, which are called OCR standard. OCR A and OCR-B are more popular in this
The OCR reader can read typewriter characters, cash register characters, and credit card characters.
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The OCR reader scans the characters through the photo-electric device and converts the reflected light data into binary data (1 and 0) for input into the computer. These are recognized in the computer from the already saved standard OCR font (Fort). Typical OCR speeds are 1,500 to 3,000 characters per second. OCR is mostly used in Billing System. OMR (Optical Mark Reader) OMR is used to check the answer sheet of an examination. These
The question papers in the examinations are alternative answer and the student has to choose one answer from four or five options and mark his answer-
(i) have to be filled. In this the light is shone on the marked paper and the reflected light is examined where the mark is present. The intensity of the reflected light from this part of the paper will be less. This technique checks only the boxes made at the fixed places on the printed card or form and the boxes filled with pencils. The speed of OMR is slow. Its Data Transfer Rate 200
to 250 pages per minute.
OBR (Optical Bar-code Reader)—The main function of OBR is to read the Vertical Bar
Which are fixed for different data, have to be scanned. use it in books
Bars and Bars are used to read the Bars printed on the back of various products.
(ii) Tracker Ball—It is a Pointing Device, it is almost similar to a mouse. We can think of it as a mouse held upside down, with the ball facing up. The pointer moves on the screen when the ball is rotated with the thumb, palm or finger of the hand.
Tracker Ball is specially made for children, through which they can play games on computer. In laptop computers also, the tracker ball is used instead of the mouse.
(iii) Lightpen- Lightpen is used to draw any shape on the computer screen. It is also a Pointing Device.
There is a photo cell in the lightpen, when we make a picture or shape on the computer screen with the lightpen, then its pulse enters the processor after being transmitted from the screen.
Lightpen is also used to select the option given in the menu. Any shape made by it can be saved in the computer's memory. It is widely used in the works of CAD (Computer Aided Design) etc.
(iv) Plotter - Plotter is an output device which serves to present charts, drawings, designs and other types of hard copy. Plotters are generally of two types – drum and flat bed plotters.
In a drum plotter, the paper on which the design is to be made is placed on top of the em. Im moves back and forth for vertical motion. In this technique, one or more pens are also used, which are horizontally attached to the em. Ink and pen move together under the control of the computer, graphs and designs are created when both move.
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In a flat bed plotter the paper is placed in a fixed position on a bed or tray. A pen is mounted on an arm, which is driven by a motor on the paper up-down (y-axis) and left-right (x-axis). The computer controls the pen in the directions of the x y axis and draws the shape on the paper.
(v) Speaker and Sound Card — With the help of speaker, we can easily receive and listen to the sound (voice), music etc. of all the programs of a multimedia computer system. Through the speaker, we can get full enjoyment of different sounds of music, movies and games.
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Compare Dot Matrix, Daisy Wheel, Laser Printer and Inkjet Printer. Compare Dol Matrix, Daisy Wheel, Laser Printer and Inkjet Printer.
Ans-
(i) Dot-Matrix Printer—It is an Impact printer. Hence it makes a lot of noise while printing. The print head of this printer consists of a matrix of pins and each pin prints a dot on the ribbon and the paper it touches. A character is formed by joining several dots. The print head has a vertical array of 7, 9, 14, 18 or 24 pins. Dots are printed out of the print head by the pins of one column at a time, due to which a character is formed in several steps. The speed of dot-matrix printer is 30 to 600 characters per second.
Dot-matrix does not have pre-formed currency characters, so it can print character graphics of different sizes, types and languages. This printer can print the output in Draft Quality Printing and Near Letter Quality Printing.
(ii) Daisy Wheel Printer – It is an Impact printer with solid font. Printing takes place in this printer with the help of wheel or chakra. Is. Due to the shape of the print head of this printer being like a blossoming daisy, it is called Daisy Wheel.
Daisy wheel printers are slow, about 60 characters per second, but have high output clarity. Its print head consists of a circle, in each "spoke" of which a character's solid font is embossed. As soon as the spoke with the letter to be printed is in the right position, an electrically operated hammer strikes it from behind. And that letter is printed on the paper. After the letter is printed, the print head moves forward to print the line of letters by this action. This type of printer is now very less in use.
(iii) Inkjet Printer—These are non-printers. In this, characters and shapes are printed by spraying drops of ink on the paper from a nozzle. The output of this printer is more clear, because each character is made up of dozens of dots.
Ink (Ink) in color inkjet printer has four nozzles (Nozzles) Cyan, Magenta, Yellow and Black. Thus they are also called CMYK printers. These four colors together can produce any color, so they are used in all types of color printers. The print quality of the output of an inkjet printer is usually 300 Dpi (Dots per inch).
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(iv) Laser Printer - Laser printer is a non-impact printer. These printers also print letters on the paper through dots, but when these dots are very small and close together, the letters are printed very clearly. Normal laser printer prints 300 x 300 dots. Modern laser printers are of 600 × 600 or 1200 x 1200 or even higher resolution. The working method of laser printers is basically the same as that of Xerox Photo Copies machines. The only difference is the formation of letters in the form of electric charge on the silicon cylinder. Bright light is used in the photocopy machine and in the laser printer a beam of laser rays with the help of a laser is projected onto a multiple mirror drum through a modulator with the help of a mirror. Due to this beam of light, the light conducting surface of the latent image of the printed mark or shape gets charged. A special type of powder is poured on this charged surface. Which is called Toner. This causes letters to appear on the surface of the paper. Laser printer printing is best. Usually it prints resolution ranging from 300 dpi to 600 or more. These Printers are also more popular nowadays, because they are faster and more efficient in printing Text & Graphics in good quality.
Laser printers are expensive. These printers can also print the output on a plastic sheet or any other sheet. Most printers have an additional microprocessor, RAM, and ROM.
Explain the difference between SVGA and XGA video standards. Differentiate SVGA and XGA video standards.
Answer – Following are the main differences between SVGA and XGA video standards-
SVGA
- The full form of SVGA is Super Video Graphics Array.
- SVGA is the unofficial successor of VGA.
- SVGA's display resolution is 800x600 pixel, XGA's resolution is 1024x768 pixel.
- The number of pixels is less in SVGA.
- The quality of the image created in SVGA is less good.
- If the size of the display is kept equal in SVGA, then a large image is formed.
- SVGA cannot display the full width of a web page on the screen.
XGA
- In XGA, if the size of the display is kept the same, then a smaller image is formed.
- XGA is the current standard resolution for web pages.
- The full form of XGA is Extended Graphics Array. XGA is the official successor of VGA.
- The number of pixels in XGA is 60% more than SVGA.
- The image produced in XGA is of much better quality.
- It is reducing, in this Liquid Crystal Display (LCD) technology is used.
- LCD has less clarity than CRT technology, it is used in Laptop etc.
Tell the difference between printer and plotter and write its different types. Explain the difference between Printer and Plotter. Explain their types. (January, 2004)
Answer – Printers – Printer is an online output device, which prints the information received from the computer on paper. This copy of the output on paper is called a hard copy. The output of information from the computer is very fast and the printer cannot work at that speed, so it becomes necessary that this information can be stored somewhere in the printer. That's why the printer also has a memory. Information is sent from the computer to this memory of the printer, from where the information is extracted and printed gradually. Following are the different types of printers-
- 1. Daisy wheel printer.
- 2. Dot-Matrix Printer
- 3. Inkjet Printer.
- 4. Laser Printer.
- 5. Line Printer.
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Plotter - Plotter is an output device that serves to present charts, drawings, designs and other types of hard copy. Plotters are generally of the following two types-
1. Drum Plotter - In an Im Plotter, the paper on which the design is to be made is placed on top of the drum. The drum moves back and forth for vertical motion. In this technique, one or more pens are also used, which are mounted horizontally. The pen and the pen move simultaneously under the control of the computer. Graphs and designs are formed when both move together.
2. Flat Bed Plotter - In flat bed plotter the paper is kept in a fixed state in a bed or tray. A pen is mounted on an arm which is driven by a motor on the paper up-down (y-axis) and left-right (x-axis). The computer controls the pen along the x-y axis and draws the shape on the paper.
Write down the advantages and disadvantages of voice recognition.
Answer – Benefits of Voice Recognition – With the development of computer, we can input data into the computer by speaking directly without typing. We can also get our commands executed by speaking. By this technique problems in data input can be avoided.
Most of the Voice Recognition System is Speaker Dependent, but nowadays Speaker Independent System is also available in the market.
Disadvantages of Voice Recognition-
1. This technique also has some problems, such as a problem that arises when data is input by voice. At this time the system checks who is speaking and what is speaking? In Voice Recognition, the voice signal can be converted into appropriate words through technical means. Most of the voice recognition systems are speaker dependent.
2. It does not even understand the difference of languages. For example, if our recognition system software is based on Hindi language then it will not be able to input data spoken in English language. 3. Where we want to input data, there should not be too much noise, because at the time of data input, our voice
Noise will also be input along with it and in which we may face trouble in opening Save data.
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