Cambridge IGCSE ICT: Input, Output, and Storage Flashcards

This set of 200 flashcards covers hardware (input, output), direct data entry, storage media, network types, security issues, and the impact of microprocessors/IoT as described in the lecture notes.

What sound waves do ultrasonic sensors emit to detect vehicles?

Ultrasonic sound waves that are inaudible to humans

How do ultrasonic sensors measure the distance to an object?

By measuring the time between the emission of the wave and the reception of the echo

What is the occupancy rate accuracy if every parking bay is fitted with an ultrasonic sensor?

$$99.9\%$$

Where were coils of wire fitted in older car parks to detect vehicles?

Into the concrete at the entrance to and exit from the car park

What is the general function of input devices?

To enter data into a computer

What are the two categories of input devices defined in the text?

Manual input devices and Direct data-entry (DDE) devices

What is the definition of a numeric keypad?

A keyboard with a group of keys representing the digits from $0$ to $9$ arranged in a rectangle

From where does a QWERTY keyboard get its name?

From the arrangement of letters on the top line of keys

Name three layouts modeled on the QWERTY keyboard.

AZERTY, QWERTZ, and the Dvorak keyboard

What was the design goal of the Dvorak keyboard?

To be more efficient by placing common letter combinations together

According to Microsoft, how many times per hour does an average user hit the space bar?

$$669\, \text{times every hour}$$

What health issue can occur from repeating actions like hitting the space bar?

RSI (Repetitive Strain Injury)

Besides computers, name three uses for numeric keypads.

Inputting PIN numbers for card payments, phone numbers on a telephone, or entry codes

What is a main advantage of a keyboard?

People are very familiar with them and they are easy to use

Name two disadvantages of keyboards.

Easy to make errors when entering data and cannot be used for creating diagrams

What is a mouse used for in a computer system?

To move the pointer/cursor on the screen within a graphical user interface

How did original mechanical mice detect movement?

They used a ball and a sensor

How does an optical mouse detect movement?

It uses an optical sensor to detect changes in reflected light

Which technologies enable a wireless mouse to communicate with a computer?

Wi-Fi or Bluetooth

What is a disadvantage of a wireless mouse regarding power?

The batteries need replacing or charging occasionally

What is an intuitive advantage of using a mouse?

They simply involve pointing at things

What is a physical disadvantage of mice?

They can be easily damaged or vandalised

Where is a touchpad typically found?

On a laptop computer next to the keyboard

What gesture allows users to zoom on some touchpads?

Using the thumb and finger

How is a trackerball described in relation to a mouse?

Like an original mechanical mouse turned upside down

Name an advantage of a trackerball over a mouse.

It is stationary and does not need a surface to be moved around on

Why are trackerballs useful for disabled people?

They may not have the freedom of movement necessary to use other pointing devices

What type of signal does a remote control send to equipment?

An infrared signal containing a specific code

What is a common disadvantage of remote control signals?

The signal can be blocked by objects or interfere with other equipment

What specialized device can be controlled by a joystick besides a computer?

A motorised wheelchair

On what part of a joystick does the stick pivot?

On a base

How does a resistive touch screen detect contact?

Two metallic layers touch due to pressure, resulting in a change in voltage

How does a capacitive touch screen detect a touch?

Sensors at the four corners detect static electricity from an exposed finger

Name two common locations for touch screens mentioned in the text.

Train station information systems and supermarket self-service checkouts

Why are touch screens considered space-saving?

The input and output devices are the same

What is a hygiene-related disadvantage of touch screens?

Problems arise with many people touching the screen

What is the purpose of a scanner?

To digitise text, diagrams, and images

How do flatbed scanners capture an image?

They shine a light at the document and direct reflected light onto a light-sensitive integrated circuit

What is the definition of a hard-copy?

A document printed on paper

What is a specialist use of scanners for old sentimental images?

Converting $35\, \text{mm}$ negatives into digital files

What is a storage-related disadvantage of scanned images?

They can take up a lot of space in storage

On what do digital cameras store photographs?

A memory card or a hard disk

In digital imaging, what are pixels?

Individual light-sensitive elements (picture elements) that detect light intensity and color

What three colors of light wavelengths are detected by camera sensors?

Red, green, and blue

What can happen if a camera's memory card becomes corrupted?

Images may not be saved or may be lost

What is a webcam?

A specific category of video camera that has no storage capacity and is connected directly to a computer

What is a video-conference?

A meeting held by people talking to each other over the internet using live video

How do microphones convert sound into data?

They convert sound waves into analogue electrical signals which are then digitised

Why is accuracy an advantage of sensors over humans?

They are more reliable as humans may forget to take readings

What is the difference between active and passive sensors regarding power?

Active sensors need a power source, while passive sensors (like mercury thermometers) do not

Where would a temperature sensor be used in a home?

In a washing machine, central heating system, or air-conditioning

What smartphone sensor detects angular rotational velocity and motion?

A gyroscope

What does a smartphone accelerometer measure?

Linear velocity

How can a light sensor be used in a car?

To decide whether or not to turn the headlights on

What type of monitor was required for light pens to work?

Old-style CRT (Cathode Ray Tube) monitors

What device has largely replaced the light pen?

A stylus

With which two types of touch screens can a stylus be used?

Resistive and capacitive touch screens

What is a disadvantage of both light pens and styluses regarding the screen?

They can impair the view of the computer screen being used

What is direct data entry (DDE)?

Methods that allow data to be entered directly without human intervention

How is data written onto a hotel room key card's magnetic stripe?

Using a magnetic stripe writer at check-in

What is a major disadvantage of magnetic stripes?

The data can be destroyed by magnetic fields

Why is a computer chip on a card more secure than a magnetic stripe?

The data is encrypted and harder to clone

What does PIN stand for?

Personal Identification Number

What is 'shouldering' or 'shoulder surfing'?

When people watch a user enter their PIN carelessly

What does RFID stand for?

Radio-frequency identification

How are animals tracked using RFID?

A tag is inserted under their skin

Name the three elements of an RFID system.

A scanning antenna, a decoder, and the RFID tag

How do passive RFID tags get their power?

From the radio signal provided by the reader

What is the typical range of RFID scanning?

About $3\, \text{metres}$

What does OCR stand for?

Optical Character Recognition

What does OMR stand for?

Optical Mark Recognition

What is the main goal of OMR scanning?

To find marks on paper in specific positions, regardless of their shape

Give an example use for OMR.

Multiple choice exam questions or election voting

What is a bar code?

A set of short parallel lines in contrasting colors that represent digits $0-9$

List four items of information typically in a supermarket bar code.

Country of origin number, manufacturer number, item number, and check digit

Is the price of an item contained within its bar code?

No, the price is not in the bar code

What does QR stand for in QR code?

Quick Response

How much more information can a QR code store compared to a bar code?

$$100\, \text{times more information}$$

What type of monitors replaced heavy CRT monitors?

TFT (Thin Film Transistor) or LED monitors

What is a main advantage of TFT monitors?

They produce far less glare, making them more restful on the eye

What is the primary role of a multimedia projector?

To project an image from a computer onto a large surface for an audience

How does a laser printer bind toner to paper?

The paper is heated by a 'fuser'

What is the name of the ink powder used in laser printers?

Toner

How do inkjet printers form images?

By squirting ink at the page out of different nozzles

What is a disadvantage of inkjet printouts if they get wet?

As the ink is often water-soluble, it will run

How does a dot-matrix printer create characters on paper?

It uses a set of pins to press an inked ribbon against the paper

In what environment are dot-matrix printers notably useful?

Dusty and dirty environments

What is a plotter?

An output device that uses pens to draw continuous lines for graphics on paper

What does CAD stand for?

Computer Aided Design

How is a 3D object produced by a 3D printer?

Successive thin layers of material are laid down in an additive process

Name a medical use for 3D printers.

Producing organs such as bones to implant in human bodies

What device converts digital signals from a computer to analogue for speakers?

A DAC (Digital-to-analogue converter)

What is a screen reader?

Special software that describes aloud what is shown on the screen for blind people

What is an actuator?

A device that responds to a control signal and produces a mechanical action

Give two examples of actuators.

Electric motors and hydraulic systems

Define a storage medium.

The material on which data is stored, such as a magnetic tape or optical disk

What does it mean for storage media to be non-volatile?

They hold data whether the computer is on or off

How is data stored on magnetic media?

In the form of tiny magnetised regions or dots representing $0s$ and $1s$

On a hard disk, what are concentric circles and track sections called?

Tracks and sectors

What is a FAT (File Allocation Table)?

A map recording where each part of a file is located on a disk