4th Class Computers Science Computer and Its Peripherals Scanner

         Scanner

A scanner creates an electronic form of the printed image which can then be manipulated, changed and modified according to the requirements. The scanners can convert any image and printed text into electronic form by shining light on to the image and sensing the intensity of the reflection at every point. The resolution of a scanner is a measure of the number of pixels it uses. Higher resolution means clearer pictures. Scanners come in 2 different models - Hand-held Scanner and Flatbed Scanner  

      Hand-held Scanner  

Hand-held scanner is a small handheld scanning device used for digitizing images. While images from a handheld scanner are considered low quality, today's technology enables full colour24 bit scanning. Depending on the scanner device type and manufacturer, handheld scanners can also define, translate and hear printed text, and can also store and beam text to computers and other devices. Hand scanners come in two forms: document and 3D scanners. Hand-held document scanners are manual devices that are dragged across the surface of the image be scanned. Hand-held Scanners are very small which can be held in a land. These are less expensive but less wide. Multiple o asses are required to scan a single page image, but their handiness is a big advantage.  

   Flatbed Scanner  

Flatbed scanners are a type of optical scanner that consist of a flat surface on which you lay documents to be scanned. Flatbed scanners are particularly effective for bound documents. Flatbed scanners are larger and more expensive scanners and create higher quality images. These scanners have a flat surface on which the printed image to be scanned is placed. Flatbed scanners can scan a page in a single pass. Flatbed scanners are very accurate and can produce images with a far higher resolution than a digital camera.                                                

 Information about the scanner is given below. Select the correct one.

1. A scanner creates an electronic form of the printed image which can then be manipulated, changed and modified according to the requirements.

2. The scanners can convert specific images into electronic form by shining light on to the image and sensing the intensity of the reflection at every point.

3. Scanners come in 4 different models.

(A) 1 and 2                                                         

(B) 1 and 3

(C) Only 1                                                           

(D) All of these

(E) None of these

Answer: (C)

Explanations

Correct Option:

(C) Only statement 1 is correct about scanners.

Incorrect Options:

(A) Statement 1 is correct but statement 2 is incorrect. Therefore, option (A) is incorrect.

(B) Statement 1 is correct but statement 3 is incorrect. Therefore, option (B) is incorrect.

(D) All the given statements are not correct. Therefore, option (D) is incorrect.

(E) All the given statements are not incorrect. Therefore, option (E) is incorrect.    

 Match the following:

         A                                                                B

1. Hand-held scanner                                  i.   High resolution

                                                                      ii.   3D scanner

2. Flatbed scanner                                       iii. Document scanner                                                                

                                                                      iv.   Optical scanner

(A) 1- ii, iii, iv, 2- i                             

(B)  1- iii; 2- i, ii, iv

(C) 1- ii, iii, 2- i, iv                              

(D)  1- i, iv; 2- ii, iii

(E) 1- ii, iv, 2-i, iii

Answer: (C)

Explanation

Correct Option:

(C) Option (C) is matched correctly.

Incorrect Options:

(A) Option (A) is matched incorrectly.

(B) Option (B) is matched incorrectly.

(D) Option (D) is matched incorrectly.

(E) Option (E) is matched incorrectly.  

• In 1953, the first high-speed printer was developed by Remington-Rand for use on the Univac computer.
• Sometimes a microphone is abbreviated as mic.  

• CD ROM: A compact disc with one or more metal layers capable of storing digital information.
• Printer: A device which produces a hard copy (permanent readable text and/or graphics) of documents stored in electronic form, usually on physical print media such as paper.
• Scanner: A device that optically scans images, printed text, handwriting, or an object and converts it into a digital image.
• Modem: A device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information.
• Microphone: A sensor that converts sound into an electrical signal.  

• A peripheral is any computer device that is not the essential computer (the processor, memory and data paths) but is situated relatively close by
• Resources on Net:   http://www.wikipedia.org  

     Abbreviations

I/O                         -                               Input and Output

VDU                       -                              Visual Display Unit

CD-ROM               -                              Compact Disc Read-Only Memory

CPU                       -                              Central Processing Unit

NIC                        -                              Network Interface Cared