Electrical Engineer Interview Questions UK: 8 Real Questions and What Interviewers Want

Most Electrical Engineer interviews in the UK follow a pattern, and knowing it beats guessing. Below are eight questions from our bank of 25, each with a note on what the interviewer is really after.

Eight Electrical Engineer interview questions, and what the interviewer is thinking

1. What does a typical day as an electrical engineer involve for you?

Why they ask: They want to check your expectations of the role are realistic and that you understand the mix of design, site and coordination work.

2. Talk me through an electrical project you have worked on and what you personally delivered.

Why they ask: They want evidence of real responsibility and an understanding of the scale of work you have handled.

3. Walk me through how you would size a cable for a final circuit or sub-main under BS 7671.

Why they ask: Cable sizing is the most fundamental design task, and they want to see the full process, not just a quick table lookup.

4. How do you calculate maximum demand and apply diversity when designing the electrical supply for a building?

Why they ask: Over- or under-estimating load costs money or risks overload, so they want to see sound judgement.

5. How do you choose protective devices and ensure discrimination in a distribution system?

Why they ask: Poor selectivity can black out a whole building, so they want to see understanding of fault levels and device coordination.

6. What is involved in the initial verification of a new electrical installation, and in what order are the tests done?

Why they ask: Testing is how an engineer proves the installation is safe, and the order matters for safety.

7. What are the key considerations when designing interior lighting for an office or similar space, and what standards apply?

Why they ask: Lighting design is a routine task for building electrical engineers and needs more than counting luminaires.

8. During an inspection you find that the contractor has installed a smaller cable than specified on a sub-main supplying a distribution board. What do you do?

Why they ask: A realistic quality and safety problem, testing technical judgement and professional integrity.

A sample answer to question 1

What does a typical day as an electrical engineer involve for you?

Days vary between design office and site, which suits me. In the office, much of the morning goes on design work: sizing cables and protective devices, producing single-line diagrams and distribution board schedules, and checking calculations. I use AutoCAD or Revit and a package like Amtech for load and fault level calculations. Then there's coordination: calls with the architect, mechanical engineer and contractor to agree containment routes, plant room layouts and loads, and I respond to technical queries from the installation team. On a site day, I'd inspect installation work against the drawings, witness tests such as insulation resistance and earth fault loop impedance, and walk through snagging. There's also paperwork, such as design risk assessments, test records and O&M manuals. In short, my job is to make sure electrical systems are safe, compliant and buildable, and a lot of that comes down to clear communication.

Common mistake to avoid: Describing only design work; sounding unaware of site realities

Want the rest?

Full model answers, key points and common mistakes for all 25 questions are on the Electrical Engineer interview questions page. The first five are free, no sign-up needed.