Page 16 - Computer Science Class 11 With Functions
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A Braille keyboard is an input device that helps visually impaired people for entering data into a computer.
1.2.2 Mouse
A mouse is a pointing device that captures the movement of a mechanical roller or a laser beam. When a user moves
the mouse, the pointer on the screen moves in the corresponding direction. This movement, along with clicks at the
specific position, is captured as input and fed to the CPU for processing.
1.2.3 Scanner
A scanner is used to convert a document or an image into digital form so that it can be viewed and saved on the
computer. Nowadays, even smartphones have applications that can scan documents.
1.2.4 Light Pen
A light pen is a device used for pointing, selecting, or drawing figures on the computer screen. It consists of a photocell
mounted on a pen-shaped tube. The position pointed to by the light pen on the screen is captured and sent to the CPU
for processing.
1.2.5 Optical Mark Reader (OMR)
An OMR recognises any mark made with a pencil or ink. It is widely used for grading specially designed answer sheets
with Multiple Choice Questions (MCQs).
A smart card reader is used to fetch input from credit cards, debit cards or ATMs.
1.2.6 Touch Screen
A touch screen panel acts as an input unit and an output display. A user interacts through this panel by touching the
desired object on the screen. It is a highly convenient user interface, especially when a user needs to enter some
identifying information about himself/ herself and choose suitable options. Day-to-day applications of touch screens
include ATMs and information kiosks. Indeed, nowadays, all smartphones provide a touch screen interface to the user.
1.2.7 Microphone
A microphone (or mic) is an input device that takes sound as input. Although human voice is the most common form
of sound input, animal voice and sound emanating from the flow of water, air, movement of trees, etc., may also be
passed to a computer as input. The analog sound signals are converted to digital form for storage and processing.
1.2.8 Bar Code Reader
A barcode encodes information in the form of a sequence of lines of different lengths, heights and widths. A bar code
reader fetches the information from a barcode printed on a product or a service by scanning its bar code. The sealed
packets of any product at any shop typically includes a barcode containing information about the products and their prices.
A QR code (Quick Response code) is a two-dimensional bar code that can be scanned with a smartphone camera. A QR
code typically contains more information than a typical bar code and is more resistant to noise and partial occlusion. A
QR code may include a link to a website, payment gateway, calendar event, or mobile application.
1.2.9 Biometric Sensor
A biometric sensor scans the physical characteristics of human beings, such as fingerprints and eyes. Such sensors are
widely used to mark employees' attendance in organisations and to provide restricted access to offices.
14 Touchpad Computer Science-XI

