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Subjects · Leaving Cert Construction Studies

Leaving Cert Construction Studies: Electrical installation

How often Electrical installation comes up on the Construction Studies papers, every year it was asked, and questions to try.

HL Asked on 3 of the last 9 Higher Level papers, most recently in 2025.

OL Asked on 3 of the last 9 Ordinary Level papers, most recently in 2024.

June 2028 is the first exam on the new Construction Studies course. These come from the 2016–2025 papers, so read them as a guide.

Electrical installation, Higher Level(6 marks)

Quick ones on Electrical installation.

(a)Circuit and cable used for socket outlets?
  1. Radial circuit in 1.5 mm² cable
  2. Ring circuit in 2.5 mm² cable
  3. Ring circuit in 10 mm² cable
(b)Circuit and cable used for lighting?
  1. Radial circuit in 6 mm² cable
  2. Ring circuit in 2.5 mm² cable
  3. Radial circuit in 1.5 mm² cable
(c)Correct cable core colours?
  1. Brown live, blue neutral, green/yellow earth
  2. Green/yellow live, blue neutral, brown earth
  3. Blue live, brown neutral, green/yellow earth
Show the answers

(a) Ring circuit in 2.5 mm² cable

(b) Radial circuit in 1.5 mm² cable

(c) Brown live, blue neutral, green/yellow earth

Your turn: Higher Level questions on Electrical installation.

Higher Level

Asked on 3 of the last 9 Higher Level papers, most recently in 2025.

Every paper, year by year

YearWhere it came up
2025Q9
2024Not asked
2023Not asked
2022Not asked
2021Q9
2019Not asked
2018Not asked
2017Not asked
2016Q9

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

More Electrical installation questions

Electrical installation, 2 marks

What is an RCBO?

  1. A meter for renewable energy output
  2. A type of cable junction box in the attic
  3. An RCD and MCB combined for one circuit
Show the answer

An RCD and MCB combined for one circuit

It trips on earth leakage like an RCD and on overload like an MCB. A fault on one circuit then cuts only that circuit, not the whole house.

Ordinary Level

Asked on 3 of the last 9 Ordinary Level papers, most recently in 2024.

Every paper, year by year

YearWhere it came up
2025Not asked
2024Q8d
2023Not asked
2022Not asked
2021Not asked
2019Not asked
2018Q8a, Q8c
2017Not asked
2016Q8f

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

More Electrical installation questions

Electrical installation, 2 marks

Colour of the earth wire in house wiring?

  1. Red and black
  2. Brown and blue
  3. Green and yellow
Show the answer

Green and yellow

Brown is live and blue is neutral. The green and yellow earth wire carries fault current safely to earth so the fuse or breaker trips.

Electrical installation, 3 marks

What does an RCD do?

  1. Stores electricity to use later on
  2. Cuts the power fast if current leaks to earth
  3. Measures how much electricity is used
Show the answer

Cuts the power fast if current leaks to earth

A residual current device compares current going out and coming back. If some leaks away, perhaps through a person, it switches off in a split second.

Electrical installation, 2 marks

Circuit normally used to feed the sockets in a house?

  1. Ring circuit
  2. Lighting circuit
  3. Doorbell circuit
Show the answer

Ring circuit

Socket outlets are usually wired on a ring that starts and ends at the consumer unit, using thicker cable than the lighting circuits.

Other Construction Studies topics

All of Leaving Cert Construction Studies