A friend who works at a startup was recently explaining that the company’s biggest problem at the moment is its inability to find suitable engineering talent.
As a barometer, one of the "questions" it poses to interviewees is this:
You have a 10V ideal voltage source in parallel with a 5Ω resistor. What is the impedance?
So far, no one has answered correctly. (The answer is provided at the end, in case you want to take a shot at it.)
My friend says, “Engineering students today can't answer basic engineering questions. And we aren't talking about tier 2 or 3 universities, either.”
She tells the story better than me, so here are her words:
This is a well-known problem, one which I have discussed/commiserated with friends from two other firms with the same issue. One is in Massachusetts and the other is in Texas, so clearly this isn’t just a regional thing.
When you look at these people's resumes, all is sunshine and rainbows. When you ask them questions about their accomplished projects, it becomes clear that they have no clue what these so-called projects were really about. They can't answer. And not just undergrads; we rarely interview undergrads. We are talking about folks with MSs and PhDs.
Some are specialized to the point of absurdity, which I suppose makes some sense if you are going to be writing a thesis, but because they lack basic understanding of the underlying physics, they really don't know their specialties all that well, either. Plus, many have difficulty communicating in English.
The bottom line is that the schools are to blame. They should not be graduating people who do not understand the material they were taught.
She went on, including what she considered unrealistic salary expectations, but you get the gist of it. Are you seeing a similar situation out there? Tell us about it in the comments section below.
Spoiler alert: The answer to the question is 0. It's a trick question. The amount of the voltage is irrelevant. The key phrase is "ideal voltage source." The real purpose was to see if they knew what an ideal voltage source was.
The point I think is important is that there are a lot of people of all educational levels that don't recognize the need for the analysis. In my experience, technicians will often persist until they come up against something they can't overcome. The problem with that is if they get a workable solution before they hit a brick wall, they will overlook hidden problems.
Those come back to bite their company years later. I know, I have dealt with several such cases.
That is why it is important to have someone on the team who not only can do the analysis, but has a good understanding of what the results mean. Often enough, only one such person is enough, but their contribution is vital. That kind of ability comes with good education (BS or higher), real interest, and good experience.
What alarms me is the number of people who call themselves engineers who are no more able to analyze a problem than a High Schooler. We count on these people to give us safe, reliable products, and they are fundamentally unable to foresee certain kinds of failures. That is why we need to find better ways to make sure the people with BS degrees are able to use what we have tried to teach them, and to value those who can.
I find a more common problem is finding people who can recognize when analysis needs to be done. I care more that a person has the instincts to know when further analysis is needed than whether or not he can do the actual analysis. I can find someone to do the analysis. It is more dangerous when someone forges ahead on something that needed analysis, and never even recognizes the need.
I have had employees that had no degree at all that had a great sense for this, and I've seen "engineers" who have no sense at all for it.
That kind of trick interview question is as old as Nodal Analysis and works great. The function is to distinguish those who pass engineering by rote memorization from those who really think. But as a janitorial service manager once observed, only one in ten candidates are worth anything -even for menial work. For better luck try Cal Poly, SLO. The hands-on orientation of the instruction ensures higher odds that the capable candidates have opportunity to acheive genuine understanding.
The Modern Casting article nails it. Part of the problem is that a whole generation of Americans raised their kids to steer clear of manufacturing. To them, manufacturing meant dark, dirty and dumb. So now, even as manufacturing offers relatively high-paying jobs for educated people with strong math skills, many are still insisting their kids go to four-year colleges and learn something that may be far less marketable.
Before I retired from GE, I volunteered to interview graduate engineers seeking employment with the company--GE Appliances, Louisville, Ky. I was one of several "screeners" that would sit for the interview and pass judgment on the candidate and his or her possibilities for success. GE Appliances, like most companies, can be a pressure cooker and few entry level engineers are ready for what they receive after employment is offered and the job duties begin. One of my pet peeves was the inability of some applicants to effectively communicate. I was blown away by incoherent sentences, sloppy thought processes and most of all, vulgar language. I don't know where along the way anyone thought communication was not part of the engineering process. Another pet peeve--you would not believe the number of times a candidate was late and / or did not show at all. Generally they wanted a second chance and sometimes they presented a valid argument. Oversleeping when the interview was a 1000 A.M. did not make the grade. I was left with the opinion that recent graduates had been accustomed to being catered to. That simply did not occur at GE.
@ttemple : Just be aware that without the BS the odds that they can do the analysis goes way down. I know there are plenty of degreed Engineers that can't do the analysis because they don't care about the math. The flip side of the coin is that they don't teach the analysis in a 2 year program at all! At best they will teach a few basic formulae. So, someone without a BS that can do the analysis either taught themselves or spent a lot of time with a very patient mentor. Neither is likely.
I have to agree that question is not a good barometer. When I read it my instant answer was 5 Ohms. That is probably what I would have answered if somebody had demanded an immediate answer to the problem. Having seen the question with a bit of leisure, my native caution kicked in. I then realized that it said the resistor was in parallel with the voltage source, WHICH IS NOT A NORMAL, USABLE CONFIGURATION. It is, in fact electrically equivalent to a voltage source that mysteriously uses power for no apparent reason. I then realized that the impedance was zero. Neither the voltage given nor the impedance given had anything to do with anything. I need to say this entire process went through my mind in less than a minute, with no reference to the actual answer (I hadn't even followed the link to the article). In short, my initial gut reaction was wrong, but when I thought about it a moment, I got it right.
My point here is that the fact that nobody answered correctly has more to do with the fact that they were asked a practically irrelevant question with an implied "hurry up and answer" than it has to do with them not knowing their stuff.
Having said that, I am personally frustrated by other more reliable evidence that engineers today don't know their stuff. Unfortunately, finding a reasonably fast way to screen out the ones who really do know it escapes me. Most people can get through a 20 question exam when they have just taken the course work. If somebody comes up with a way to quickly and reliably identify those who "get it", please pass it to the Universities. If they implement that, the quality of their graduates will skyrocket.
A real power supply can appear "close enough to ideal" over the range it is used but things get goosy if you ask a really stiff battery (usually as close as we can get to an ideal voltage source) to provide a few mega amps for a millisecond to a few seconds, then eat the backwash politly. The ideal is supposed to be 0 ohms, but it does not exist in reality, so the question should travel to how close in what environments. Most of the supplies I deal with are great sources, up to their current limits, given a few milliseconds to respond, but are crappy at sinking enough current to hold the voltage in a large transient with lots of back current. And I am a physicist, a mostly self taught electronic engineer of last resort. Very right that most of our engineers do not have the physics they need and great gaps in their circuit theory. We are now, however, talking microwaves in the 300 GHZ range, and I admit my physics is very not up to that. And if you want to consider quantum computing and the like, I think we are hitting a "cusp" where the whole physics of our engineering is changing rapidly. Fun times if you are up for it. A very bad time for the US to be trying to shave costs on tech education.
I like wise thought zero for the Voltage source and then the 5 ohms and wondered what was it connected to and thinking of the Thevin and Norton equivalents.
I had a question in an interview about powering electonics after the source is lost. There has to be enough capacitance in the circuit to hold up. But if the power is cut off at the lowest operating voltage spec. The circuit is nt longer operating in spec unless it is design for an even lower voltage cause the caps are at or lower that the cut off. Now you could have a circuit to pump up the voltage and it will last till it meets its lower operating limit. But that was not the point. So I did not get that position but did get another at that company. Guess the manager spent too much time in management. Cant create something from nothing.
Perhaps if I clarify my work environment; I work in a chemistry department maintaining research equipment that spans decades of technology. Vacuum tubes, anyone? Money is not available in the quantities needed to update nor keep up to date, the equipment. There is also a need to understand across several disciplines. It is also multicultural and the majority 'customers' (grad students), are coming and going. Generally, chemists don't know electronics and physicists think they know. As a result, requests can come in that make absolutely no sense. And almost always, it needs to be explained why without offending someone. And sometimes, we don't have the answers but we have to go find them, no choice. Learning the engineering is simple, trying to fix an employee causing interpersonal problems is not simple, easy or maybe even possible. I use questions where the answer is only part of what I look at - or the answer is irrelevant and my observation is of interest. Basically, all the opinions given are right for different situations and work environments.
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