Engineering Interviews Be Like

i've been interviewed a lot for mechanical engineering jobs i've definitely done well over 50 mechanical engineering job interviews and i'm going to show you exactly what those interviews are like it's about 15 minutes before when your interview is supposed to start and you're a little stressed because after all the rejections you faced you're hoping that this one is the one you're hoping that this interview is the one that finally lands you a job offer okay moment of truth time to join the virtual interview hi tamer my name is well with the y sorry for joining a couple of minutes late here is this still a good time yeah uh still a good time how's your day been so far good um well that's great i'm doing well too thanks for asking anyways i'll start off with learning a bit about the company and the team then i'd like for you tell me a bit about yourself your projects and we'll end off this minute interview by asking you some technical questions yeah sounds good i'm a senior design engineer here at wings and i've been with the company for just over two years now i mean here at wings we basically create flying dinner tables essentially we sell these dinner tables to restaurants and they are able to see customers about 100 feet up in the air this is incredible for the environment because now these restaurants don't need to occupy as much land and so we're looking to hire one mechanical engineer to help us essentially accelerate the world towards a better future in food robotics now tell me about yourself well it's cool to hear a little bit more about wings i'm a recent mechanical engineering graduate from the university of waterloo and over the past five years of my studies i was able to accumulate just over two years of work experience i started off working as a mechanical engineer i started in toronto i then took on a bigger role in my second internship working as a manufacturing engineer at a larger company called ecobee i then took that knowledge and worked at another company as a product design engineer afterwards i worked at a startup called blended as a mechanical engineer okay tell me more about blended yeah well similar to wings disturb also happens to be in the food robotics industry a lot of my work there involved working with product managers to turn the product requirements into engineering requirements create a detailed design assess design issues and prototype pretty quickly okay well so looking at your resume and portfolio here i say you've done a bunch of projects maybe just pick your favorite and tell me a little bit about it for sure so one of my favorite projects is a personal project of mine that i like to call happy i work in this project with a few friends and the product is essentially a toilet attachment that analyzes your urine before it's flushed away to give you information that can allow you to track your health and detect diseases like diabetes or utis how did you make that i created 3d cad models and detailed 2d engineering drawings and solidworks for many of the parts that make up this product i also use arduino and several sensors for the electrical infrastructure and i fabricated it using 3d printing and laser gutting it was overall a pretty successful project because i was able to provide dehydration levels and accuracy of 95 so i'm pretty proud of that seems like you're quite passionate about this project of yours oh yeah he definitely likes me i'm definitely getting the job there's no way he would have said that otherwise i understand this project was just a prototype if you were to mass producer at high volume what would you do huh okay tayman think think what do i know about high volume oh okay i think i know what i'm gonna say okay so for a high volume of parts i would use injection molding because it can handle relatively complex geometry any other reasons yeah well although the process can be expensive up front this process can end up actually being a lot cheaper if making a large enough number of parts all right uh what type of plastic would you make this out of so ideally i want to use a plastic that is moisture resistant and has decent impact strength so a plastic like polypropylene would be a good choice here what about the use of a different plastic like polycarbonate for example um do you mind if i just think about that for a second sure okay let me try to google something real quick uh no no no oh that could work okay well although it is possible to use it polycarbonate isn't as machinable as polypropylene this means it'll be harder to create the shape that we want or it will cost us more okay sure let's get into the technical questions now i'm gonna send you a link that's essentially a virtual whiteboard so please click on it and let me know if you can see what i'm showing you sure did you get it uh no not yet oh oh just got it okay first question we have a solid rod and a hollow rod both of them are sliding down a ramp which one do you think will reach the ground first if they have the same mass this is such an easy question i studied this exact question last night let me just act like this is the first time i'm hearing this hmm let me think about that for a second well if the rods are sliding and without air resistance they will reach at the same time but if they're sliding with air resistance it is likely that the hollow reaches first as its geometry faces lower drag okay well now instead of having the same mass let's say they have the same volume but different mass would that change your answer same volume okay i don't remember seeing this question before okay tamer just relax this rod is rotating down the hill what equations can i use for this f equals m a now okay maybe i can use the total equation yeah i think that could work uh do you mind if i draw on your whiteboard go for it we know that t equals i alpha where t is torque i is moment of inertia and alpha is angular acceleration another equation we know that defines the moment of inertia is i equals m r squared so if we combine both equations and isolate for alpha we get the alpha equals t over m r squared so the rod that will reach first would be the one greater acceleration and according to the equation just arrived the one with lower mass much greater angular acceleration and therefore that one will reach the bottom first okay nice let's move on to the second question okay i definitely got this one right let's go okay tamer chill keep it cool now as a mechanical engineer we work a lot with different types of metals two of the most common ones are steel and aluminum could you maybe tell me a little bit about both and what the differences are between them okay so aluminum tends to be more flexible than steel and more corrosion resistant however steel is denser and harder than aluminum but aluminum tends to have a greater strength to weight ratio though okay great so let's say we have two pieces of metal one is steel and one is aluminum and we take just a piece of metal and we stretch them could you maybe tell me a little bit about how the stress on these two pieces of metal would act um okay so because steel is more could you actually draw a diagram on the virtual whiteboard to answer this question diagram i thought this was an explaining question what should i draw maybe he wants me to draw a stretch string curve okay so i'll draw a stress strain curve to answer this question for steel as you strain it or stretch the metal as you said it will undergo elastic deformation until it reaches its heel strength afterwards it will go through plastic deformation the difference between elastic and plastic deformation is that elastic is reversible whereas plastic deformation is irreversible okay and what about aluminum yeah so aluminum isn't as strong so it's global look something like this where the y axis represents the stress the metal can face and the x axis represents how much metal is strained or stretched and so the end of both of these curves represents when the metal breaks after being stretched clearly aluminum will break under lower stress than the steel okay so we have about 10 minutes left now so let's move on to the third and final technical question this one is just meant to give me an idea of how you think about design problems okay hit me did i just say hit me in the interview who the hecks has hit me in an interview oh my god that sound professional okay it's okay hopefully hopefully you didn't hear that you have three light bulbs upstairs and three light switches downstairs if you can only go up once to determine which switch connects to which bulb what would you do to figure that out could you give me a minute to think about that sure okay so i have three light bulbs and three light switches three light bulbs and three light switches what happens when i turn on a light switch well light bulb turns on okay but what else happens what else happens oh well the bulb heats up okay so i have an answer to figure out which light switch belongs to which light bulb i think what you do is you turn one on then turn one on one minute later and leave one off whichever bulb is the hottest is the first the warm one will be the second and the one that is off would be third okay great so you only have a couple minutes left before i have to drop off so i'll give you these last few minutes and maybe ask me some questions okay well i kind of love to know a little bit about what the next steps are in this interview process great question so how the process this company usually works is first you do an interview with me and if i like you which i think i do you then move on to the second stage of interviews will you do a panel interview with five different engineers similar to this one someone should reach out to you to schedule those but for now that's about it uh thanks for your time man have a good rest of your day thanks youtube wait a second interview there's more

Channel: Tamer Shaheen

Views: 301,119

Keywords: mechanical engineering interview questions and answers, technical interview questions, interview questions

Id: SlK_2O2Rv4w

Length: 8min 29sec (509 seconds)

Published: Mon Sep 20 2021