For hardware types ask them to draw a full wave bridge rectifier.
At one place a recent-grad systems engineer was hired to do board repair. When asked to identify components, he said "I think those are resistors because they have colours on them."
He lasted about a week.
For a real engineer, ask how many soldering irons they own. We tend to upgrade from a simple one when we can afford it, but can't get rid of the old one because it may be useful for something. Then there are high power units for big jobs.
Have a small device on the table that isn't screwed together. Se how much time is spent looking inside, how long is spent operating it.
Engineers are more interested in what us inside something than what it does.
This assumes the device is a well-known gadget, not a functioning TriCorder!
Drones are, in essence, flying autonomous vehicles. Pros and cons surrounding drones today might well foreshadow the debate over the development of self-driving cars. In the context of a strongly regulated aviation industry, "self-flying" drones pose a fresh challenge. How safe is it to fly drones in different environments? Should drones be required for visual line of sight – as are piloted airplanes? Join EE Times' Junko Yoshida as she moderates a panel of drone experts.