Scioly.org

Digital Multi meters are usually fairly accurate, assuming that you are measuring within the normal range of the meter (i.e. not trying to measure micro-amps or milli-ohms with a general purpose meter) , and the meter has fresh batteries.

Souces of "error" are more likely tolerance in components (resistors), and variance in your power source (which I am guessing is a battery).

It really does depend on the meter though, people that work in the field(shipboard/oil rig stuff) generally send in their really nice meters every 2 or so years for recalibration, and they're only normally out a few hundredths of a volt or so... then again the cheap 'radio shack special' meters can come being .1v or so out. Most of your experimental error, however, comes from batteries that aren't 1.5v and in the .01v or less error range, the fact that hardly anyone accounts for wire resistance.

I think most error is going to come from the voltage source your using and the tolerance of the resistors in your circuit... in some applications you might have error associated with your meter (like wire resistance and ideal versus non-ideal resistor's and meter's inside the device).. but it should be minimal.. Then again if you have large resistance in your circuit and have a small resistance in your voltmeter because of some reason then you'll have error there.. Though for almost all tests in science olympiad and other circuit lab tests they expect a large margin of error due to multiple reasons. I recently took a test and on it if you were 10% within finding the capacity of the capacitor you got full credit for the problem. So it all depends. Though in some respect's is better to use crappy meters because then you can talk about the error in the circuits inside the meter and get a better understanding of how things work. meh..

Can anyone recommend any books for Shock Value for, like, beginners? Kinda new to this event, and I would greatly appreciate any book titles. Thanks!

sciencepenguin9 wrote:Can anyone recommend any books for Shock Value for, like, beginners? Kinda new to this event, and I would greatly appreciate any book titles. Thanks!

For this (and any event really), you should always check out the official event page on soinc.org (http://soinc.org/shock_val_b) which always lists suggested resources.

This is my favorite event.

Messed up pretty badly at Northridge Invitationals in Indiana yesterday. Our bus came in late, we were supposed to have extra time, but the supervisor didn't let us have the extra time to do 2 stations, sucks. The test topics were pretty different from what I centrally studied, for example Color-Coded resistors on one section I had no clue whatsoever, and another station we had to name different people fundamental in the development and discovery of electricity and what-not, had no idea. I had the people in my notes, but none of them fit along the definitions given, made me mad. Disappointed in myself for that!

Anyways, can anyone link me to a good kit/parts for building some circuits? I need some practice and need some good quality pieces.

Bozongle wrote:Anyways, can anyone link me to a good kit/parts for building some circuits? I need some practice and need some good quality pieces.

I'm a coach for Div. B.

All the parts you need are available on Amazon.

I ordered a 365-pc box of resistors by Elenco. Also a bunch of 10-inch alligator clip test leads, and $10 multimeters - I ordered five for the team of 10, reckoning that each pair of students would bring one meter. It's easier for them to use meters they are already familiar with.

I made power supplies by using a few spare power supplies, the little black cubes that plug into the wall and deliver a few volts DC and about 500 mA. I soldered on some red and black alligator clips. One exercise for the students was to analyze their power supply to determine what resistor would take the rated current, and what resistor would dissipate 1/2 watt at the rated voltage.

For our last session, before the competition, I am going to make a multiple resistor network. They will model it, determine what the voltages ought to be, and measure the voltages to determine if their calculations were correct.

- Eric

Being a first-time coach for Shock Value, I have to comment that one of my frustrations with this event has been the lack of diligence on the scope. Some competitions include detailed questions on electromagnetism, alternating currents, types of magnetism, network theorems ... my 5th and 6th graders have to go from a minimal understanding of electricity, to mastering the algebra for Ohm's Law, through to solving circuit problems that call for step-by-step analysis. It's a tall order. They all have EE parents, but they still struggle with just the fundamentals. And these are cream-of-the-crop kids: We're in one of the best school districts in the country. The event captains have done a pretty good job of constraining the scope; I don't know what I'm going to say if the kids are faced with a bunch of esoteric questions. The potential scope is so broad that it often will end up being luck whether the kids have studied a particular aspect.

Regardless, it has been a great experience, and the kids tell me this is their favorite event. I gave them a little quiz on the first day and I am looking forward to returning their quizzes to them after the event to show them how far they came.

I share your frustrations, and I've been doing this for a little while now. The best you can do is work on predicting what aspects of the topics listed in section 3.c. of the rules your kids may be tested on and teach them the material while dropping the leftovers in their binders (while all the while not making their binders too voluminous meaning useless for their purposes). The disadvantages at their age, including the catching up needed on the algebra, is certainly frustrating at times, but seeing what they are capable of at the end of the season is incredible. When worrying about scope of the event, remember this: the questions have to be age-appropriate (grades 6-9) and on the topics (even if the rules are worded as 'topics may include', you can expect most supervisors to work primarily from that assuming they've read the rules at all). Prediction is your best weapon, then.