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Subjects · Leaving Cert Computer Science

Leaving Cert Computer Science: Embedded systems & sensors

How often Embedded systems & sensors comes up on the Computer Science papers, every year it was asked, and questions to try.

HL Asked on 2 of the last 5 Higher Level papers, most recently in 2023.

OL Asked on 5 of the last 5 Ordinary Level papers, most recently in 2025. banker

Embedded systems & sensors, Higher Level(6 marks)

Quick ones on Embedded systems & sensors.

(a)What is an embedded system?
  1. A general-purpose desktop PC used for many tasks
  2. A computer built into a device for one dedicated task
  3. A server in a data centre that hosts websites
(b)Which of these contains an embedded system?
  1. A web server
  2. A laptop
  3. A washing machine
(c)Which sensor would detect how bright it is outside?
  1. A light-dependent resistor (LDR)
  2. A servo motor (moving actuator)
  3. A thermistor (temperature sensor)
Show the answers

(a) A computer built into a device for one dedicated task

(b) A washing machine

(c) A light-dependent resistor (LDR)

Your turn: Higher Level questions on Embedded systems & sensors.

Higher Level

Asked on 2 of the last 5 Higher Level papers, most recently in 2023.

Every paper, year by year

YearWhere it came up
2025Not asked
2024Not asked
2023A6
2022Not asked
2021B15

Links open the State Examinations Commission’s paper for that year.

More Embedded systems & sensors questions

Embedded systems & sensors, 3 marks

A sensor is read every 0.5 seconds. How many readings are taken in 1 minute?

  1. 60
  2. 30
  3. 120
Show the answer

120

There are 2 readings each second and 60 seconds in a minute: 2 x 60 = 120. The time between readings is the sampling interval.

Embedded systems & sensors, 3 marks

What is a microcontroller, such as the one on a micro:bit?

  1. A program that runs a small web server on the board
  2. A small computer on one chip, with memory and I/O pins
  3. A sensor on the board that measures light levels
Show the answer

A small computer on one chip, with memory and I/O pins

Microcontrollers are the heart of embedded systems: they read sensors, run one program and drive outputs such as LEDs and motors.

Ordinary Level

Asked on 5 of the last 5 Ordinary Level papers, most recently in 2025. banker

Every paper, year by year

YearWhere it came up
2025B13
2024A11
2023A2
2022A3
2021A7

Links open the State Examinations Commission’s paper for that year.

More Embedded systems & sensors questions

Embedded systems & sensors, 2 marks

An embedded system is…

  1. A laptop that is used for many tasks
  2. A website that is built inside an app
  3. A computer built into a device to do one job
Show the answer

A computer built into a device to do one job

e.g. the controller in a car's airbags or a smart thermostat. Embedded systems are usually small, cheap and low-power.

Embedded systems & sensors, 2 marks

Which is an example of an embedded system?

  1. A spreadsheet on a laptop
  2. The controller in a microwave
  3. A desktop PC in an office
Show the answer

The controller in a microwave

The microwave's controller reads the keypad and timer and controls the heating. It does one job only, unlike a general-purpose PC.

Embedded systems & sensors, 2 marks

Which sensor would a smart heating thermostat use?

  1. Temperature sensor
  2. Light sensor
  3. Accelerometer
Show the answer

Temperature sensor

It reads the room temperature, compares it with the setting and switches the heating on or off: input, process, output.

Other Computer Science topics

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