Tuesday, April 17, 2012

Electrifying, My Dear

Thought for the day: If it weren't for electricity, we'd all be watching television by candlelight. [George Gobel]

[THEME: Amateur radio]

Amateur radio operators are expected to learn some fundamentals of basic electronics, and one of the things we learn about is OHM'S LAW, which expresses the relationship between voltage, current, and resistance.

Voltage (E) refers to the amount of electromotive force (EMF) applied to a circuit, and can be compared to water pressure going through a pipe. The more voltage, (or pressure) the more electrons (or water) flowing. Voltage is measured in volts.

Current (I) measures the number of electrons flowing. No, you can't count them as they flow past any more than you can count the individual drops of water in a waterfall, but just as water is measured in quantities such as gallons, the electron flow is measured in amperes. One ampere is equal to 6.24 x 10 to the eighteenth power. (That'd be a LOT of counting!)

Resistance (R) is just what it sounds like. If you put a blob of hair or sponge into a water pipe, it'll block the flow. In the same way, resistors resist the flow of electrons, and limit the amount of current flowing through a circuit. Resistance is measured in ohms.

Here's a bunch of different resistors. See those color bands on them? Each color represents a different number, and in simplest terms, the numbers express the resistor's value.

So what does Ohm's Law tell us? That within a circuit, voltage equals current times resistance. E=IR.

                                                               So, there ya have it.


  1. Resistance is my favorite thing to calculate! It's the artist in me. One of the most elegant things ever devised was Wheatstone's Bridge --from the 1800s-- a comparator circuit still at the heart of analog computers.

  2. I always had a hard time with this stuff for some reason. Maybe cause I couldn't see it.

  3. Love the comic! Too funny.

    Thank you for the great comment today. :)


  4. Now here is a science lesson for the day! Thanks for sharing. I didn't know there were still ham radio operators out there.

  5. Dang, and I always thought Ohm's law had something to do with Nirvana. The band that is.

  6. punny and clever. Thanks for visiting wordsplash. I'm now following you and looking forward to more zany humor and electrifying amps. Very fun.

  7. Heeheehehhe, what a wonderful laugh I got here this mornin'!!! Good medicine, ya know.

    Sweetie, I just wanted to thank ya for visitin' with your sweet comment and hoppin' on my blog. I sure hope ya enjoy the ride!

    God bless ya and in the words of that wacky old Granny Clampett, ya'll come back now, ya hear!!!

    Enjoy your day my friend! :o)

  8. Okay, now I have it...I'm just thankful we have electricity :)

  9. Well that was enlightening! Seriously, though. ;) (Great analogy with the water and pipe). Ohmmmmmmmmm...

  10. Love the "Join the Resistance" cartoon. Who would have conducted that meeting? Mho?

  11. I used to build electrical circuits for a hobby back in my teens. Can't remember them now, but I used to know those color codes off by heart, including the last multiplier band, and could read off the resistance at a glance. Am I officially nerdy? :)

  12. Electricity ... the only thing I know about it is that I'm useless without it.

  13. Geo- I'm impressed! (Although I'd never made a connection between the calculation of resistance and art before.) Yes, the Wheatstone bridge is definitely cool and elegant in its simplicity, and quite accurate, too. Alas, nowadays, most people use a cheap multimeter from Radio Shack.

    Rubye- You're right. It's a lot easier to get a handle on things we can actually see.

    Skippy- Glad ya liked the comic, kiddo. 12:34

    Stephen- You're welcome. There are still a LOT of hams around. More than 702,000 in the U.S. alone, and millions more in other countries.

    Mr. C- No, no, you're confused. That's the SUPREME (or is that Supremes?) OHM Law.

    Joanne- Thanks for stopping and for signing on as a follower. Welcome aboard! If you like "punny" and "zany humor", you've come to the right place.

    Nezzy- Thanks for stopping in, dear lady. That's mighty neighborly of you. And please, drop in any ol' time. The front porch light's always burning.

    Tracy- You and me both! Thanks for visiting.

    Carrie- Ohmmmm, good one!

    G- HA! Yeah, that'd work.

    Botanist- Yeah, that's worthy of an honorary nerd membership card. (Would you believe there's a song based on "The Twelve Days of Christmas" that helped me remember the color values?)

  14. Delores- Ooops, how'd I miss you the first time? Sorry about that. Anyhow, I'm sure it'd take a lot more than a loss of electricity to make YOU useless. I'm betting you have quite a few survival tricks up your sleeve.

  15. Love the cartoon, very clever!

  16. Many people have tried to teach me about electricity, starting with my Physics teacher at school and including Mr A who can't understand my dumbness about it. It's no good. I have a mental block when it comes to electricity. As long as the light goes on when I flick the switch then that's good enough for me.

  17. You should have been my physics teacher as school, I might have learnt something :)

    I have now gained some knowledge...off to share it now along with some poop form my own blog :) x

  18. Love the cartoon! You should have been a teacher. You are good at explaining this stuff. :-)

  19. Hey....I learned about electricity today! Now its time to go re-wire the garage!! :)

  20. Ohmmmmmm . . . Ohmmmmmmm
    Shhh! I'm meditating.


  21. I'm in the same boat as a lot of others here...it isn't something I've ever had to use much and so never learned or retained it. You seem to have a really good grasp on it. That's impressive! Nice post.

  22. Julie- Puns may be the "lowest form of humor", but they crack me up. Glad ya liked it.

    Rosalind- A lot of times when my grandmother turned on a light switch, she'd say, "God said let there be light, and there was light." She regarded electricity as a bit of a miracle, and I think to some degree, most of us do.

    Dina- HA! Thanks, and thanks for dropping by.

    Tracy Jo- What a sweet thing to say. I have a lot of respect for teachers.

    DL- Oh yeah, that's like me saying I read a book today, so I'm ready to win a Pulitzer for fiction.

    Janie- Okay, I'll be vewy vewy qwiet.

    Marcy- By George, she's got it!

    Tracy- Okay, I'm done yammering about electronics for awhile. Promise.

  23. Hi Susan .. Ohm's Law .. good thing to know about - even if it's only the name .. now that cartoon at the end .. pull the resistor and join in ..

    Great - love it .. cheers Hilary

  24. Hilary- That's right. Ya never can tell when someone might walk up to you on the street and ask if you've ever heard of Ohm and his law. (hey! It could happen!) Cheers back atcha.

  25. Learned Ohm's Law in 1958. Can still read the resistors markings. How? I still remember the color coding via
    Bad Boys Rape Young Girls But Violet Gives Willingly. (It's not PC today, but it sure has stuck with me for over 50 years!) LOL

  26. DC- Hey, whatever works! I learned the coding with a totally stupid song to the tune of "Twelve Days of Christmas," but my hubby learned via your mnemonics, too. I reckon nowadays, they just look at a chart.