Input and output devices practice

Original questions All questions on this page are original work, written in the Cambridge IGCSE style. They are not from past papers. They test the same concepts and skills the syllabus rewards.

Keep these straight

Into or out of.

Input: enters data for processing (keyboard, mouse, microphone, camera, scanners, touch screen).
Output: presents or acts on results (screens, projectors, printers, speaker, actuator).
Touch screens: resistive (pressure, two layers), capacitive (charge, finger), infra-red (beams).
Choosing: link the device's feature to the scenario's need.

Recall

[2 marks]

State what is meant by an input device and an output device.

Input device: allows data to be entered into a computer for processing. ✓
Output device: presents the results of processing (in a form the user can see, hear or use). ✓

Explain

[3 marks]

Describe how a barcode scanner reads a barcode.

Light (a laser or LED) is shone onto the barcode. ✓
Dark bars reflect less light and light/white spaces reflect more; sensors detect the reflected light. ✓
The pattern is converted into a number (binary) that the computer can process/look up. ✓

Explain

[3 marks]

Describe how a capacitive touch screen detects a touch.

The screen has a layer that holds an electrostatic charge/field. ✓
A finger (a conductor) touching the screen changes the charge at that point. ✓
Sensors at the corners measure the change to calculate the position of the touch. ✓

Apply

[2 marks]

A museum wants a very large interactive display that visitors can touch with a finger or a pen. Identify a suitable type of touch screen and justify your choice.

Infra-red touch screen. ✓
It works with any object (finger or pen) and is suitable for large screens. ✓

Explain

[4 marks]

Describe how a laser printer produces a printed page.

A laser creates a pattern of electrical charge on a rotating drum. ✓
Toner (powder) is attracted to the charged areas of the drum. ✓
The toner is transferred from the drum onto the paper. ✓
The paper passes through a fuser, which uses heat to fix the toner. ✓

Recall

[2 marks]

A greenhouse system uses a motor to open a window. Identify the type of device the motor is and state whether it is input or output.

An actuator. ✓
It is an output device. ✓

Mark this once you have attempted all six and checked your working. It records a Practiced badge on the topic and adds a one-time bonus. Revealing the solutions alone does not count.