The short answer: electrical engineering interviews test fundamentals (Ohm’s law, AC circuits, power), your specialty (power systems, controls, electronics, or building electrical design), safety and codes, troubleshooting, and behavioral questions about projects and teamwork. Expect to explain your reasoning, sometimes with a quick calculation or sketch. Below are the common questions with short answers, grouped by area, and what to prepare.
What the job involves
The U.S. Bureau of Labor Statistics describes electrical and electronics engineers as people who “design, develop, and test electrical and electronic equipment, components, and systems,” including electric motors, navigation and communications systems, power generation equipment, and electrical systems for vehicles and aircraft. The median pay for electrical engineers was $120,630 in May 2025, and employment is projected to grow 10% from 2025 to 2035.
Circuit fundamentals
“State Ohm’s law and Kirchhoff’s laws.”
Ohm’s law: V = I × R. Kirchhoff’s current law: currents into a node sum to zero. Kirchhoff’s voltage law: voltages around a closed loop sum to zero.
“What happens to total resistance in series and in parallel?”
In series, resistances add. In parallel, the reciprocal of the total is the sum of reciprocals, so the total is smaller than the smallest resistor.
“What does a capacitor do? An inductor?”
A capacitor stores energy in an electric field and resists changes in voltage; an inductor stores energy in a magnetic field and resists changes in current.
AC and power
“What’s the difference between real, reactive and apparent power?”
Real power (watts) does useful work; reactive power (VAR) moves back and forth between source and load in inductors and capacitors; apparent power (VA) combines them. Power factor is real ÷ apparent power.
“Why does power factor matter, and how do you correct it?”
A low power factor means more current for the same useful power, so bigger conductors and more losses, and utilities may charge for it. Inductive loads are usually corrected with capacitor banks.
“Why is power transmitted at high voltage?”
For the same power, higher voltage means lower current, which reduces resistive losses (I²R) in the lines.
Power systems and protection
“What does a circuit breaker do, and how is it different from a fuse?”
Both interrupt fault current. A fuse melts and must be replaced; a breaker trips and can be reset.
“What is protective coordination?”
Setting protective devices so the one closest to a fault trips first, isolating only the affected part of the system.
“What’s a short-circuit study for?”
Calculating available fault current so equipment is rated to interrupt or withstand it, and so protection can be set correctly.
“What’s the purpose of grounding?”
Safety (a path for fault current so protection operates and touch voltages stay low) and system stability.
Motors and drives
“How does an induction motor work?”
The stator’s rotating magnetic field induces currents in the rotor, which produce torque. The rotor turns slightly slower than the field (slip).
“Why use a variable frequency drive?”
To control motor speed by changing frequency, saving energy on fans and pumps and allowing soft starts.
Electronics
“What does a transistor do?”
It acts as a switch or an amplifier, controlled by a small current (BJT) or voltage (MOSFET).
“How does a voltage regulator work?”
It keeps output voltage steady despite changes in input or load: linear regulators drop the extra voltage as heat; switching regulators switch rapidly and are more efficient.
Safety and codes
“How do you work safely on electrical equipment?”
De-energize and apply lockout/tagout, test for absence of voltage, use appropriate personal protective equipment, and follow your organization’s electrical safety program and applicable codes and standards.
“Which codes and standards have you worked with?”
Name the ones relevant to your work and region (for example, the National Electrical Code in the U.S.) and how you applied them.
Design and troubleshooting
“Walk me through how you’d size a cable for a load.”
Determine load current, apply derating for ambient temperature and grouping, check voltage drop over the length, confirm short-circuit withstand, and pick the size that satisfies all, per the applicable code.
“A motor keeps tripping its breaker. How do you troubleshoot?”
Check the load and mechanical binding, measure current against nameplate, check for phase imbalance or loss, insulation resistance, and the protection settings. Work from safe, simple checks to more invasive ones.
Behavioral questions
- Walk me through a design project you led. What constraints did you face?
- Tell me about a time a design didn’t work as planned. See tell me about a time you failed.
- Tell me about a time you worked with mechanical or controls engineers. See teamwork questions.
- Tell me about a time you raised a safety concern.
For related roles, see our hardware engineer, mechanical engineer and robotics engineer guides.
Frequently asked questions
What questions are asked in an electrical engineer interview?
What is power factor?
Why is electricity transmitted at high voltage?
How much do electrical engineers earn?
How do I prepare for an electrical engineering interview?
Sources
- U.S. Bureau of Labor Statistics, Occupational Outlook Handbook, Electrical and Electronics Engineers. Read on 1 October 2026.
