Computer Input Devices and Scanners

Questions and Answers

What is the definition of an input device?

Any device that allows a computer to receive data from the outside world.

How many types of scanners are there?

What type of scanner is used at airports to read passport pages?

2D scanners

What type of scanner uses gamma rays?

SPCET scanners Signup and view all the answers

What is the name of the input device that reads a series of dark and light lines of varying thickness?

Barcode reader Signup and view all the answers

What does the light line represent in a barcode?

0 Signup and view all the answers

Where is the most common place that barcode readers are used?

Supermarkets Signup and view all the answers

What does QR stand for in QR code?

Quick Response Signup and view all the answers

How many times more data (approximately) can a QR code hold compared to a barcode?

200 Signup and view all the answers

What are 3 automatic adjustments that a microprocessor in a digital camera makes?

Shutter speed, aperture size, size of image Signup and view all the answers

What is the name of the cell that light passes through the lens onto in a digital camera?

Light-sensitive cell Signup and view all the answers

What determines the file size of a photograph?

Number of pixels Signup and view all the answers

What are two external factors that affect the quality of the photograph?

Type of lens and lighting Signup and view all the answers

What is the name for the most common input device?

Keyboard Signup and view all the answers

What do most computer systems use to prevent the microprocessor waiting for keys to be pressed?

Keyboard buffer Signup and view all the answers

What injury are users prone to who do a lot of typing?

Repetitive Strain Injury (RSI) Signup and view all the answers

What are the two most common pointing devices?

Mouse and trackerball Signup and view all the answers

Which port connects the mouse to the computer?

USB Signup and view all the answers

What 3 common features do all mice have?

2 buttons and a scroll wheel Signup and view all the answers

What is the most common environment for where trackerballs are used?

Control rooms Signup and view all the answers

What is the name of the device that is used to input sound into a computer?

Microphone Signup and view all the answers

What is the name of the device that converts analogue data to digital data?

Analogue to Digital Converter (ADC) Signup and view all the answers

What are the 3 types of touchscreen?

Capacitive, Infra-red, Resistive Signup and view all the answers

What general type of touchscreen allows users to utilize while wearing gloves or using a stylus?

Resistive Signup and view all the answers

What are the most common types of sensors?

Monitoring and Control Signup and view all the answers

What is the name of the device that converts digital data to analogue data?

Digital to Analogue Converter (DAC) Signup and view all the answers

What component of a machine is responsible for controlling systems in control applications?

Actuators Signup and view all the answers

How would monitoring sensors be used in a hospital?

To monitor a patient's vital signs Signup and view all the answers

What are two ways that control sensors are used on the street?

Street lighting and traffic light control Signup and view all the answers

In street lighting, how long is a lamp left on or off for before readings are sampled again?

30 minutes Signup and view all the answers

What are the benefits of high-level languages?

Easier to read and understand, easier to write in a shorter time, easier to debug, easier to maintain. Signup and view all the answers

Examples of high-level languages?

C++, Delphi, Java, Pascal, Python, Visual Basic Signup and view all the answers

Why do people use low-level languages?

To make use of special hardware, special machine-dependent instructions, to write efficient code. Signup and view all the answers

What are the advantages and disadvantages of machine code?

Difficult to understand, not commonly used by programmers, written in binary. Signup and view all the answers

Define a compiler.

A program that translates a program written in high-level language into machine code. Signup and view all the answers

Study Notes

Input Devices

Input devices allow computers to receive data from the outside world.
Common input devices include keyboards, mice, and barcode readers.

Scanners

There are five types of scanners.
2D scanners are used at airports to read passport pages.
SPCET scanners utilize gamma rays for scanning.

Barcodes and QR Codes

Barcode readers read a series of dark and light lines of varying thickness.
Light lines in a barcode represent the value of 0.
Barcode readers are predominantly found in supermarkets.
QR stands for Quick Response, allowing for faster data access.
QR codes can hold approximately 200 times more data than traditional barcodes.

Digital Cameras

Digital cameras automatically adjust shutter speed, aperture size, and image size.
Light-sensitive cells capture light through the lens in a digital camera.
The file size of a photograph is determined by the number of pixels.
Quality of a photograph can be affected by the type of lens and lighting conditions.

Common Input Devices

The keyboard is the most common input device used.
A keyboard buffer prevents the microprocessor from waiting for key presses.
Repetitive Strain Injury (RSI) is a common injury among frequent typers.

Pointing Devices

Mice and trackerballs are the two most common pointing devices.
Mice connect to computers via USB ports.
Mice typically have two buttons and a scroll wheel.
Trackerballs are often used in control room environments.

Sound and Data Conversion

Microphones are used to input sound into computers.
Analogue to Digital Converters (ADC) convert analogue data into digital form.
Digital to Analogue Converters (DAC) do the opposite, converting digital data to analogue.

Touchscreens

Three types of touchscreens are: capacitive, infra-red, and resistive.
Resistive touchscreens allow usage with gloves or stylus.

Sensors

Sensors can be classified as monitoring or control sensors.
Monitoring sensors, used in hospitals, track patient vital signs.
Control sensors manage systems such as street lighting and traffic control.

Programming Languages

High-level languages are easier to read and understand, quicker to write, simpler to debug, and easier to maintain.
Examples of high-level languages include C++, Java, Python, and Visual Basic.
Low-level languages are used for special hardware, specific machine instructions,less memory consumption, and speed optimization.
Machine code is difficult to comprehend, primarily written in binary, and not commonly used by programmers.

Compilers

A compiler translates high-level language programs into machine code, processing one line at a time.
Compiled programs can run independently without the compiler.

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Description

This quiz covers various input devices, focusing on scanners, barcode readers, and QR codes. Learn about how digital cameras function and the technology behind capturing images. Test your knowledge of these essential computer components and their applications.