IGCSE Computer Science - Input and Output Devices

How does a barcode scanner work?

• Converts pressed keys into binary data

• Scans a barcode and retrieves the stored data

• Tracks light reflected from a QR code

• Captures sound and converts it into binary

How does a digital camera capture data?

• It scans text into a document

• It detects movement using light reflection

• It captures light through a lens and converts it to binary

• It tracks the position of a cursor

What happens when you press a key on a keyboard?

• The key sends sound signals to the computer

• The key is scanned and saved as an image

• The key’s ASCII or Unicode value is converted to binary data

• The keyboard emits light to confirm the input

What does a microphone do in a computer system?

• Scans QR codes to retrieve data

• Converts soundwaves into binary signals

• Converts electrical energy into mechanical movement

• Tracks cursor movement

How does an optical mouse track movement?

• Captures the pressure applied on the device

• Uses sound waves to track movement

• Captures light reflected from a laser onto a surface

• Detects the user's fingerprints

What does a QR code scanner do?

• Captures sound and converts it to binary

• Tracks cursor movement on a computer

• Captures light reflected from a QR code and converts it to binary

• Converts binary data into text

What is the purpose of a 2D or 3D scanner?

• Converts sound to digital signals

• Tracks user interaction on a touchscreen

• Captures light reflected from objects and converts it to binary data

• Prints documents onto paper

How does a touch screen detect input?

• By capturing light reflected from barcodes

• By detecting pressure, conductivity, or light and calculating the touch coordinates

• By emitting sound signals

• By scanning the user’s face

How does an actuator work in a computer system?

• Converts sound into text

• Outputs mechanical movement or action based on signals from a control system

• Displays images using a light source

• Projects data onto a large screen

How does a DLP projector display an image?

• By spraying liquid ink onto a screen

• By rotating a drum and applying toner

• By reflecting light from tiny mirrors through a lens

• By using sound waves to generate pixels