Electrical Engineer interview questions and how to answer them
An electrical engineering interview is mostly a test of whether you can be trusted with a stamped drawing. You'll get fundamentals, a design problem or two, and questions about the time something you built didn't work. Here's what each question is really checking and how to answer it like someone who's done the work.
What happens in each round
- 1
Recruiter screen
What happens
Whether your background matches the side of the field they hire for (power, controls, electronics, or building systems), your licensing status (EIT or PE), and whether you can explain a past project in plain words without hiding behind jargon.
- 2
Hiring manager
What happens
How you think through a design from requirements to drawings. Expect questions about the tools you've used, codes and standards you've designed to, and how you handled a review comment you disagreed with.
- 3
Technical panel or design exercise
What happens
Fundamentals under light pressure. You might mark up a single-line diagram, size a feeder, read a schematic, or walk through a fault. They care more about your method and your checks than about getting the exact number in your head.
- 4
Team fit and site walk
What happens
Whether you'd work well with drafters, technicians, contractors and the project manager. At some firms you'll walk a plant floor or substation, and they'll notice whether you know where to stand and what to ask.
Questions you're likely to get
1.Walk me through how you'd size a feeder for a new motor load.
Why they ask
It's the bread and butter of power and building work. They want to see that you follow a sequence and don't skip the checks that bite people later.
How to answer
- Start from the nameplate and the code tables for full-load current, not a guess
- Apply the continuous-load and motor multipliers your code requires, then pick the conductor by ampacity
- Correct for ambient temperature, conduit fill and terminal ratings
- Check voltage drop over the run, and upsize if starting current will sag the bus
- Coordinate the protective device so it rides through inrush but still protects the conductor
2.Explain the difference between a short-circuit study, a coordination study and an arc flash study.
Why they ask
These studies get confused constantly, and the person who mixes them up will produce labels that don't match the gear.
How to answer
- Short-circuit tells you the available fault current, so you can check equipment ratings
- Coordination sets the devices so the one closest to the fault trips first
- Arc flash uses the fault current and clearing times to estimate incident energy and set PPE and labels
- Mention that they depend on each other, so a change to one means rerunning the others
- Name the software you've used, like SKM, ETAP or EasyPower, and what you entered by hand
3.A breaker keeps tripping on a circuit that tested fine at commissioning. How do you find out why?
Why they ask
Field troubleshooting separates people who've been on site from people who've only worked in a model.
How to answer
- Ask what changed since commissioning: new loads, a process change, heat, a firmware update
- Look at the trip type first, whether it's instantaneous, long-time or ground fault, because each points somewhere different
- Pull load data with a power quality meter or clamp meter before touching settings
- Check for harmonics from drives or electronic loads if the neutral or breaker runs hot
- Fix the cause, not the symptom, and document the setting change if one is justified
4.How do you approach grounding and bonding on a new design?
Why they ask
Grounding mistakes are quiet until they're dangerous. They want to hear that you know the difference between the two words.
How to answer
- Separate the jobs clearly: grounding ties the system to earth, bonding gives fault current a low-impedance path back to the source
- Talk about the single neutral-to-ground bond point and why a second one causes objectionable current
- Mention separately derived systems, like a transformer secondary, and where their bond goes
- Bring up sensitive equipment grounding if you've done data rooms or instrumentation
5.Tell me about a design of yours that failed or had to be reworked.
Why they ask
Every working engineer has one. Saying you don't is the fastest way to lose the panel's trust.
How to answer
- Pick a real one with real consequences, like a panel that didn't fit the room or a relay setting that nuisance-tripped
- Say plainly what you missed and why it slipped through review
- Describe the fix and who you had to tell, including the client or contractor
- End with the check you added to your own process so it doesn't happen again
6.What codes and standards have you designed to, and how do you stay current when they change?
Why they ask
Code cycles change requirements, and an engineer who designs from an old edition creates change orders.
How to answer
- Name the ones you've actually used, like the NEC, NFPA arc flash rules, IEEE standards, or UL listings for panels
- Say which edition your local authority has adopted matters more than the newest one
- Mention how you learned about a change that affected your work, like new GFCI or surge protection requirements
- Show you call the inspector or plan reviewer early when something is unclear
7.How would you read and check a schematic or single-line diagram someone else drew?
Why they ask
A lot of the job is reviewing. They want to see whether you catch things or just initial the title block.
How to answer
- Start at the source and follow the power down, checking ratings at every step
- Look for mismatches between the drawing, the panel schedules and the load calcs
- Check that device ratings exceed available fault current
- Mark up with clear, specific comments the drafter can act on, not vague notes
8.Where are you on licensing, and what's your plan for the PE?
Why they ask
At consulting and utility firms, a PE decides who can sign drawings. They're checking fit with their promotion path.
How to answer
- Say plainly whether you've passed the FE and hold an EIT designation
- Give an honest timeline for the PE Electrical and Computer exam, and which module you'd take, such as Power
- Mention the experience you're logging under a licensed engineer
- If you're in a role that doesn't need a PE, say so and explain why that fits your plans
9.A contractor on site says your design won't work and wants to change it. What do you do?
Why they ask
Field pushback happens on every project. They want an engineer who listens without folding.
How to answer
- Go look, or get photos, before deciding anything
- Take the contractor seriously, since they're often right about fit and routing
- Separate what's a preference from what affects safety or code compliance
- Put any accepted change through an RFI or a revised drawing, never a handshake
10.How do you manage your time when you're on several projects with deadlines landing the same week?
Why they ask
Most engineers carry a few projects at once. Missed submittals cost the firm money and goodwill.
How to answer
- Describe how you track deliverables, whether that's a shared schedule, a Planner board or a simple list
- Talk about flagging a conflict early to your project manager instead of the day before
- Give an example where you traded scope or asked for help and the project still went out clean
11.What's the most complex system you've worked on, and what was your specific part?
Why they ask
Resumes blur individual work with team work. They want to know exactly what you touched.
How to answer
- Name the system in plain terms, like a substation upgrade, a PLC-controlled line or a hospital emergency power system
- Say which pieces you designed, calculated or tested yourself
- Name the tools you used, like AutoCAD Electrical, Revit, MATLAB or a PLC programming environment
- Mention one hard decision you made and what drove it
12.How do you think about safety when you're in the field?
Why they ask
Electrical work can kill people. A candidate who's casual here doesn't get hired, however sharp they are.
How to answer
- Talk about lockout/tagout and verifying absence of voltage yourself, every time
- Mention arc-rated PPE and reading the label before opening gear
- Say you'll stop work if something looks wrong, even when it's inconvenient
- Give a moment where you did exactly that
Mistakes that sink good candidates
Guessing a number with confidence instead of saying how you'd look it up and check it
Taking credit for a whole team project without naming your own piece
Talking about safety or lockout procedures as optional when the schedule is tight
Badmouthing contractors, drafters or a past employer's reviewers
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