Return of the Quiz

The Free Day Quiz has returned! Browse through all of the questions that were available during the chaos and test your knowledge.

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If the Free Day Announcement was the beginning and the Free Day Event the exalted sequel, then today marks the completion of the trilogy!

Return of the Quiz

Okay, so it's not that epic. But the quiz is back. Check it out!

A question about voltage dividers

The questions look just as they did before but without all that pesky Free Day logic. Flip through them one by one if you like and save your answers.

All available quiz questions

In total there are 63 questions covering 17 different bite sized tutorials. Perhaps more will be added in the future, provided we can pry an engineer away from his or her toys for a while. Enjoy!

Comments 55 comments

  • ajcrm125 / about 13 years ago / 1

    Man I crushed this quiz. Curse you free day... I would have "gotten paid". :)

  • Dynamo / about 13 years ago / 1

    Good questionary!

  • ruZZ / about 13 years ago / 1

    The count down was more exciting than new years! :)
    A little frustration along the way, and I almost fell asleep or left for dinner, but it all paid off in the end! I scored big time when sh17 hit the fan.. I'll admit, I used google a little, but using it quickly is a skill too =) I actually got a question wrong, but it's submission timed out!!! which gave me time to re-think.. managed to rock 8/8 before pens down. Thanks SF!! :)
    Now, this isn't a complaint ( I couldn't possibly.. ), but a suggestion of fairness. Some questions just take longer to answer. If the quiz is ever done again(PLEASE PLEASE :D ), I suggest maybe giving the questions a time-ranking, and giving everyone some quick Q's off the bat, which get longer to solve as it progresses. This will give less seasoned electro-geeks a better chance at hitting Q.2 before the bell rings. I just wouldn't want to be a newcomer trying to convert hex>dec and being to slow for Q1 after reading a bunch of tuts and being able to score a few otherwise. The ones who can answer them all quick enough are likely to be loyal deserving customers anyway.
    THANKS GUYS!! (the WHOLE crew!!)

    • EvilGenius121 / about 13 years ago / 1

      we counted about the last 20 sec of new years. I spent about an hour watching it go down... i got through 4. i admit i was one of the newbies (i got stuck at q. 3) but persevered :) post christmas presents!!

  • EternityForest / about 13 years ago / 1

    The question about battery charge time should say "in theory" or "Under ideal conditions" because inefficiencies would most likely extend the charge time a little.
    Other then that, i got them all pretty much right except for a few of the number format conversions.
    Great Quiz SparkFun! Thanks!

  • einro / about 13 years ago / 1

    Last time I worked this much with RS232 was in the early 80's. I do remember RS232 receivers were required to work with an input as little as +/- 3v. In the days before Maxim, we needed a short distance send ONLY from a single 5v cpu (Z80). We used a flip-flop and connected to just the Q and *Q. It worked more like a common mode (RS485) signal but the Q used as ground gave *Q the illusion of +/- 5v signal. :-)

  • Fun, but very annoying to know that I would have gotten $100 if the servers would have let me at it. :P

    • Erik-Sparkfun / about 13 years ago / 1

      Actually, if the servers had perfect response, you would've had about a 1 in 4 or 5 chance of getting $10 (depending on loyalty payouts), as there likely would've been at least another 40,000 people trying to answer the first quiz question at the very same time you did. ;)

  • EvilGenius121 / about 13 years ago / 1

    Im just wondering how i got past so many on free day.. some of these are really hard! :)

  • Remowylliams / about 13 years ago / 1

    I had a lot of fun answering these. glad to know I got a few right.

  • Benito / about 13 years ago / 1

    I was hoping something like this would be added after Free Day!

  • Kli_Womagni / about 13 years ago / 1

    Re. Static Electricity: The primary reason we don't die from static, as I understand it, is that the body's capacitance is tiny. About 100pF or so. There's no limitation anywhere causing the current or power to be low, since humans are primarily a capacitive source. The current and power are huge, but only for a fraction of a second, and only a tiny amount of energy can be dissipated (since only a tiny amount was stored).
    Also, what does "total power" mean? Average, peak, integral .dT?

  • Kli_Womagni / about 13 years ago / 1

    I'm sure that the answer to "Charging Billy's Battery" is not 10 hours. If that were true, it'd be 100% efficient. As well as that, only really crap chargers (which you don't want) are constant current all the way. Better ones use constant voltage at the end, when cell voltage is at the maximum acceptable level (normally 4.2V). 11 hours is the closest answer, but I'd say 12 or more to be sure.
    While we're at it, good luck getting the AAs in "Billy's Battery Capacity I" to drive RGB leds. Remember that battery capacity for alkalines is typically quoted down to 1.0 or even 0.8V. To make use of all of the capacity, you'd need a blue LED running on

    • Kuy / about 13 years ago / 1

      In Billy's Battery Capacity II, there's a 1000mAh battery driving 9 LEDs with 10mA through each, and an ATtiny85 consuming 8mA. As we all (should) know, LEDs are usually driven in series to reduce resistive losses. This means the system current draw is 18mA in that configuration, and the battery will last 55 hours. The quiz considers this wrong, however, and it was the only question I missed on the real free day quiz - not to seem ungrateful, but does this bug anyone else? :-)
      The question does not state the configuration of the circuit or (critically) the voltage of the battery. My solution would require a ~20V Li-Ion battery, not at all uncommon for laptops.

      • Kamiquasi / about 13 years ago / 1

        18mA for all 9 LEDs plus the chip wouldn't make sense, though, unless he only ever wanted an off-white color from those RGB LEDs.
        On the other hand, it is referring to an actual product - the LectroCandle - so we could check out its sheet to figure out the circuit configuration.
        Either way gives an incorrect answer to the question posed with the -given- information, though :)

      • Valen / about 13 years ago / 1

        /unpicking nit
        The problem description did mention it was powered by a lithium-polymer battery. Still, not if it were multiple cells in series. It didn't say anything about voltage, but I guess implies 3.something volt.

    • Valen / about 13 years ago / 1

      I agree, the other questions in this set were pretty clear with the emphasis on theoretical charge/discharge time. This one didn't emphasize 'theoretical' so I went for 11 hours as well.

    • SpeakEZ / about 13 years ago / 1

      I guess that is why it was multiple choice. It was not intended to be an Electrical Engineering Final Exam - just something to make you think.

  • mman1506 / about 13 years ago / 1

    i did well on most of the quiz except for the pull up resistor and numbers part. I've never needed to use binary so I'm kinda wondering why it was included?
    oh and keep doing free day!

    • Danny. / about 13 years ago / 1

      Than you are realy good with HEX or ony using arduino's?

    • SpeakEZ / about 13 years ago / 1

      It is pretty tough to harness a microcontrollers abilities without knowing binary. Binary IS the language of computers. Hex only exists to keep the numbers shorter :)

  • x3n0x / about 13 years ago / 1

    Well, first of all, If I would learn to read carefully, I would have missed one less.
    Some of them, ahem, that package one, SIL? Never heard of such a thing... It was kind of a crap shoot. Same with the GPS one. I personally think the user will contribute more to error than the mountains will... but anyway... Still a really good refresher, and great stuff that everybody working with electronics should understand....

    • nathan7 / about 13 years ago / 1

      SIL is actually quite common, especially for motor drivers and stuff. You could even say TO220 is a form of SIL.

    • MikeGrusin / about 13 years ago / 1

      We're glad to hear that; that's -exactly- what we were hoping for by adding the quiz this Free Day. =)

  • sgrace / about 13 years ago / 1

    You don't need to pry me away from my toys to get questions from me!

  • Attie / about 13 years ago / 1

    Great quiz!
    I just sent a link to two of my uni lecturers with the first years in mind! He agreed that it was a great quiz and asked if there was any possibility for firmware (C specifically) questions to be added!
    I do feel that this is very hardware oriented... and hardware is (generally) just a pile of tin if it wasn't for the firmware!

    • Draxssab / about 13 years ago / 2

      If they put questions on firmware they should do it for Assembly, as it's the real language of the micro.
      And i may be oldschool but... I've made electronic for a LONG time without any programmation/firmware, and it was not a pile of tin :P

    • nathan7 / about 13 years ago / 2

      ..uh uh, ever seen analog electronics with firmware?
      And quite a bit of digital electronics needs no firmware either. (as a matter of fact, the 7400 series and 4000 series do exist >_>)

    • Attie / about 13 years ago / 1

      okay okay... ill take that back!
      but micros/fpgas/cpld/etc... are more and more commonly replacing multiple ICs in small/cheap/low power systems...
      fpgas also often also have a processing core within - NIOS for example!

    • Danny. / about 13 years ago / 1

      How about FPGA's, VHDL is no firmware :-P, but almost everything is possible.

    • SpeakEZ / about 13 years ago / 1

      I serviced electronic devices for an Office Supply company in the late 1970's. ALL calculators at that time were strictly SSI chips (plus resistors, diodes, and transistors) - the 'firmware' WAS the electronics. Good quiz, btw.

  • Eric-Montreal / about 13 years ago / 1

    In the "Resistor connectivity" question about the mosfet transistor, what do you call "keep the mosfet in a known low state" ?
    For me that means the state where it's output (drain) is low (led is on). In this case, the state is impossible to achieve with this circuit if the 3.3V is out.
    Since the answer you expected was "R1", the question could have been "Which resistor should you connect to the gate pin in order to keep the mosfet GATE in a known low state" or "Which resistor should you connect to the gate pin in order to keep the LED off"
    During the real "free day", the server was so slow I could not get a single page to load (except the error message), then it suddenly started working at near normal speed, but I only had time to answer 3 questions before the whole thing was over. Thank you Sparkfun for the 30$ gift !

  • Melt-O-Tronic / about 13 years ago / 1

    DOH! I would have easily maxed out Free Day if I could have gotten through more than 2 question! Moar servrz, plz. K? But the Melt-O-Tronic is ecstatic about melting his new acquisitions.

    • Erik-Sparkfun / about 13 years ago / 1

      Actually, with 45,000 unique requests, it likely means you only would've had time for at the most ONE question before the money was up if the servers had been able to serve everybody. ;)

      • AdamTolley / about 13 years ago / 1

        That's really interesting.
        It was non-ideal server conditions that made free day ideal for some of its participants, and exciting for most of them.
        It almost seems like next year's free day (assuming there is one) would need to include some sort of random selection process to keep things rewarding for participants.
        This year, you could have just given everyone $5-10 instead, and it would not have been nearly as exciting. That is to say, the prospect of getting a lot of money is what makes free day attractive, not just to the total amount given away by SFE.
        Is free day sustainable given rising participation, high expectations and non-infinite funds?

  • DMKitsch / about 13 years ago / 1

    I have found an error. If you click on the submit button but have not ticked an answer you get the something broke screen

  • V3rtigo / about 13 years ago / 1

    I would have rocked this quiz had I taken it. Thanks Computer Engineering degree from MSOE

  • phishinphree / about 13 years ago / 1

    I believe I found an error on one of the serial questions:
    Which of the following statements on the differences between RS-232 and TTL is not true?
    I believe the correct answer should be: RS-232 signals are inverted from TTL signals: a positive voltage represents a logic '0', while a negative voltage is a logic '1'
    Not, An RS-232 signal requires two stop bits while a TTL signal only uses one.
    Please correct me if I'm wrong but I remember spending a afternoon in lab debugging a project before I learned that rs232 is inverted.
    EDIT: Nevermind, inverted logic got me again! I should learn how to read.

    • JWRM22 / about 13 years ago / 1

      RS232 isn't +25/-25V, that had to be the right answer. The data/speed remains the samen (beside its inverted)
      to the quiz:
      i need to L2R.. whats the BINARY representitive of 0xA2 uhm.. 162?

      • nathan7 / about 13 years ago / 1

        According to the spec it's max -25/+25. It's usual and according to spec to use -12/+12 though.

    • Kamiquasi / about 13 years ago / 1

      yeah - takes you back to your high school years, doesn't it? 7 questions in positive form, then suddenly they throw a negative one at you and it sneaks in under the radar. Grrr. I did catch that, though, and still answered it incorrectly ;)

  • Max O'Lydian / about 13 years ago / 1

    I almost messed up on the first question- first thought was correct, but then I started to overthink it, knowing how sneaky these sparkfun guys are. Load current, anyone?

  • Kamiquasi / about 13 years ago / 1

    Fun little quiz for beginners and even just as a reminder for us tinkerers! I already messed up the RS232 "not" question.. I rarely deal with those.
    I do think at least one of the questions might need a little nudge, though: "Quiz Question - Nominal AAA Voltage". Although the correct answer should be obvious, it's a bit misleading to speak of a nominal AAA Voltage; AAA being a form factor, rather than a Voltage standard.

  • jakkjakk / about 13 years ago / 1

    It'd be great if there was a score.

    • I'm on it.
      *edit: There's now a basic stats box on the quiz index page. I might flesh it out a bit more in the next couple days.

    • Kamiquasi / about 13 years ago / 1

      If there were, my score would be (3 errors) (63-3)/63100% ~= 95.24%
      Questions I got wrong:
      35: Interference. *eyes his TomTom and questions the question's validity

      40: Logic Level I. Silly misreading of the question.
      58: Comparison of Signals. Haven't touched RS232 in ages.
      Edit: Not 2, but 3 errors.. forgot about that logic level one, though that was more a reading issue than a logic states comprehension issue cough

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