OT - explaining electricity to Boy Scouts

James Mcquade · Oct 31, 2016

Hi all,

I have volunteered to teach the electrical merit badge to a group of boyscouts
Saturday and i'm kind of stuck on something.

I can explain the electrical charge and electron flow or current flow (depending which way you want it) and resistance.

What I am looking for is an example they can understand and relate to.
Any examples are much appreciated.

thanks,
james

PapaSmiff · Oct 31, 2016

Well, you can use the old "Ping-Pong balls rolling through the garden hose" analogy for current.
For resistance, pull out a flashlight bulb and show how it works (making a connection across the filament). Then, pull out a battery and touch both ends with your fingers, showing that your body has a much higher resistance than the contacts in the flashlight.

dragonx556 · Oct 31, 2016

The water analogy helped me when I was first learning.

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/watcir.html

PapaSmiff · Oct 31, 2016

If you have a few resistors lying around, you could make a circuit with the batteries and the flashlight bulb and show how the bulb dims when you have a increase in circuit resistance.

the_msp · Oct 31, 2016

https://www.youtube.com/watch?v=mvuHsu8S6v8

Tom Jenkins · Oct 31, 2016

Here are some hands-on electro-magnetism activities you might find useful:
http://www.coolmagnetman.com/magindex.htm

Helliana · Oct 31, 2016

Series and parallel circuits with light bulbs is a decent demonstration too. You can see how the bulbs in series gets dimmer the more you add bulbs you add because of voltage drop. Also can show how if one bulb goes out, they all go out.

If you have a current meter, you can also show how the current is much higher in parallel because the same voltage is applied to every bulb.

Ron Beaufort · Oct 31, 2016

the light bulb idea works fine - as a "first time through" demonstration ...

but ...

if you're going as deep as Ohm's law calculations, some things won't work out "right" because of the tungsten effect ...

so ...

you might get a bunch of the little "cup heaters" that you can use to boil water for tea, etc. ... you can measure the amps, volts, etc. and come out with "beginner level" numbers ... just be sure to keep water in the cups - or they'll quickly burn out ...

jraef · Oct 31, 2016

Get a roll of pennies and line 10 of them them up in a straight row, all touching each other. Then flick one on the end with your finger and watch the one on the other end pop away, demonstrating that the electrons don't actually move as much as people think they do, they mostly just pass the force, EMF, along the conductor from one to another. Then do 20 or 30 in a row and when you hit the end one, you see that some of the energy gets lost in bouncing some of them off to the side, demonstrating losses as some of the energy is turned into waste (heat) in the conductor.

Then build a Tesla Coil and make their hair stand on end...

Plastic · Oct 31, 2016

Ohms Law

ndzied1 · Nov 1, 2016

If you don't have it, get the merit badge book. They are usually very well written for the target age group. It will also make sure the boys are learning the things that the merit badge councilor will be signing off on them learning.

Most troops keep a library of merit badge books on hand for borrowing.

The water analogy is very good. If you can find someone with a snap circuits kit, those are nice too as you can put together several different things in a short amount of time. With even the simple kit, you could show an LED connected directly to the battery (don't do this for long, it could burn up) and it will be bright. Then you can add a resistor and it will be dim. Then you can put it in backwards and it won't light.

drforsythe · Nov 1, 2016

Use the merit badge book. In order to maintain some semblance of consistency, the rules of being a merit badge counselor state that a counselor may not add or subtract requirements. That being said, the merit badge books provide the right amount of info in order to complete the requirements. There is nothing wrong with adding explanations that clarify an idea, it helps keep the instruction interesting. However, make sure the basics from the book are covered.

James Mcquade · Nov 1, 2016

Thanks everyone,

I haven't received the book yet.
I have printed the paperwork from meritbadge.org for the class.

james

dwoodlock · Nov 1, 2016

The example that was used for us when I was in tech school was a lake/reservoir with a dam.

John Morris · Nov 1, 2016

Plastic

I would like to ask your permission to print the pic you posted and hang it on the wall above my desk.

That thing is wicked wrong in so many ways. Guys in the shop would get a kick out of it. Pun intended.

OT - explaining electricity to Boy Scouts

James Mcquade

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PapaSmiff

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dragonx556

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PapaSmiff

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the_msp

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Tom Jenkins

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Helliana

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Ron Beaufort

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jraef

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Plastic

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ndzied1

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drforsythe

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James Mcquade

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dwoodlock

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John Morris

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