## Ohm's Law / EE equations work problems (was E I R P quizzes / problems for study)

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Looking for a source that has quizzes and / or work problems around Ohm's law and the other equations used in EE.

Working through NEETS is fun, and I'm learning a lot, but I need more experience working through these types of problems to internalize the equations and relationships.

Things like:

A series circuit contains two resisters in series. R(1) = 256 ohms, and R(2) = 30 ohms. The circuit current is 6 amps. What is the:

a) source voltage;

b) voltage dropped by each resistor;

c) total power; and

d) power used by each resistor.

I don't need the answers to this particular problem, as I have already solved it. But where can I find more like this -- with answers so I can check my work -- for more practice?

Thanks!

EDIT: BTW, I do know how to Google (http://www.lmgtfy.com/?q=ohm%27s...). Just wanted informed opinions on people's favorites... :-)

• "Give me six hours to chop down a tree and I will spend the first four sharpening the axe."  -- Abraham Lincoln
• "All right wise guy, where am I?"   -- Daffy Duck
• "Well, we're safe for now. Thank goodness we're in a bowling alley."  -- Big Bob, Pleasantville
Last Edited: Fri. Apr 1, 2016 - 04:14 PM

From the subject line, I thought it had something to do with Effective Isotropic Radiated Power.

Jim

Until Black Lives Matter, we do not have "All Lives Matter"!

ka7ehk wrote:
From the subject line, I thought it had something to do with Effective Isotropic Radiated Power.

Meant to change that before submitting. Cryptic subjects are not helpful!

• "Give me six hours to chop down a tree and I will spend the first four sharpening the axe."  -- Abraham Lincoln
• "All right wise guy, where am I?"   -- Daffy Duck
• "Well, we're safe for now. Thank goodness we're in a bowling alley."  -- Big Bob, Pleasantville

Couldn't you just write a C program to test yourself?

The fact is that V=IR (and hence I=V/R etc) as well as P=IV are just basic algebra so you should be able to write C that uses rand() to pick random values for 2 variables in each equation then invite the user to calculate/provide the third.

(at least that's what I'd do, but then I'm a bit mangler not a sparkie!)

My High School Electronics teacher would meet us at the door every day and hand us a DC analysis quiz, these daily tests would add a few more resistors each day but we still had the same about of time to solve them (10 min's IIRC) and counted as 50% of our grade.  By the end of the semester, I could solve them in my head by the time I reached my desk.

Jim

(Possum Lodge oath) Quando omni flunkus, moritati.

"I thought growing old would take longer"

ki0bk wrote:
these daily tests would add a few more resistors each day but we still had the same about of time to solve them (10 min's IIRC) and counted as 50% of our grade.  By the end of the semester, I could solve them in my head by the time I reached my desk.

This is exactly what I am looking for. Perhaps if I cannot find such a thing I should create such a thing. Would be sure to learn it doing that as well!

clawson wrote:
Couldn't you just write a C program to test yourself?

I would be more inclined to use Javascript / CoffeeScript / Scala / Java and put it on the web, but yes, that would work as well!

Thanks!

• "Give me six hours to chop down a tree and I will spend the first four sharpening the axe."  -- Abraham Lincoln
• "All right wise guy, where am I?"   -- Daffy Duck
• "Well, we're safe for now. Thank goodness we're in a bowling alley."  -- Big Bob, Pleasantville

In consideration of others, please RTFM!

Check out training sites for would-be radio operators (hams).   IIRC, they do some ohms law stuff.   You can just skip the non-applicable questions.

For example, at http://aa9pw.com/radio/ a sample test had (remarkably few relevant questions. :-()

Still, there are a lot of other "circuit analysis quize" sites...

https://en.wikiversity.org/wiki/...

http://www.brandonfla.com/circui...

I wonder where my 1967 edition is hiding?

Ross McKenzie ValuSoft Melbourne Australia

You want to practice "mesh currents" and "node voltages" solving n equations in n unknowns?

If you don't know my whole story, keep your mouth shut.

If you know my whole story, you're an accomplice. Keep your mouth shut.

Anything dealing with Kirchoff's and Thevenin's Laws will stand you in good stead.

This might be a useful collection of reading material also.

http://www.electronics-tutorials...

Ross McKenzie ValuSoft Melbourne Australia

Last Edited: Sat. Apr 2, 2016 - 02:01 PM

Great web site from Colin Mitchell in Australia 'Talking Electronics'

Imagecraft compiler user

Some really good feedback all around, appreciate it!

I have started writing an application, web based, to help with this. Started with Typescript, but it is driving me up the wall, so going to switch back over to CoffeeScript / Javascript so I am not trying to learn a new language on top of the EE stuff. Too distracting and frustrating!

Thanks for all the responses!

• "Give me six hours to chop down a tree and I will spend the first four sharpening the axe."  -- Abraham Lincoln
• "All right wise guy, where am I?"   -- Daffy Duck
• "Well, we're safe for now. Thank goodness we're in a bowling alley."  -- Big Bob, Pleasantville

On a side note: In my very first circuits class, I always wrote Ohm's Law at the top of the page, something that I continued to do on every circuits test I ever took after that. Even though I could solve the problems in my head, I just found it comforting.

This simulator might be of interest.

sweet!

Imma print and post this http://security.livewatch.com/wp... at my workstation. Perhaps it will make me lazy though...

• "Give me six hours to chop down a tree and I will spend the first four sharpening the axe."  -- Abraham Lincoln
• "All right wise guy, where am I?"   -- Daffy Duck
• "Well, we're safe for now. Thank goodness we're in a bowling alley."  -- Big Bob, Pleasantville

The Idiot sees the Eagle over the Rabbit : I = E/R

The Rabbit sees the Eagle over the Idiot : R = E/I

The Eagle sees the Rabbit beside the Idiot : E = RI

If you don't know my whole story, keep your mouth shut.

If you know my whole story, you're an accomplice. Keep your mouth shut.

Ross... you look at the Talking Electronics site yet? (Do you know the guy? Colin Mitchell)

Imagecraft compiler user

bobgardner wrote:

Ross... you look at the Talking Electronics site yet? (Do you know the guy? Colin Mitchell)

No and no.

Ross McKenzie ValuSoft Melbourne Australia

The Idiot sees the Eagle over the Rabbit : I = E/R

The Rabbit sees the Eagle over the Idiot : R = E/I

The Eagle sees the Rabbit beside the Idiot : E = RI

I've never understood this.  I mean, this is why one takes Algebra in high school, right?  No weird poems, no "triangles", just memorize "E = I*R" and derive everything else "as needed", or "as you go."

westfw wrote:

The Idiot sees the Eagle over the Rabbit : I = E/R

The Rabbit sees the Eagle over the Idiot : R = E/I

The Eagle sees the Rabbit beside the Idiot : E = RI

I've never understood this.  I mean, this is why one takes Algebra in high school, right?  No weird poems, no "triangles", just memorize "E = I*R" and derive everything else "as needed", or "as you go."

And some of us are rather visual thinkers.

If you don't know my whole story, keep your mouth shut.

If you know my whole story, you're an accomplice. Keep your mouth shut.

And some of us are rather visual thinkers.

I figure all of us are a combination.  'A little from column A, a little from column B'.

For knot-tying, I'm with you Tom:

For formulae, I'm with Bill.

For example, all you need to know for high-school physics (all of Newtonian physics, really) is:

• F = ma
• You can't push a rope

Those two things, combined with simple mathematics (at its most complicated, Trigonometry), will let you solve any problem.  The key is recognising the 'F', the 'm', and the 'a'.

 "Experience is what enables you to recognise a mistake the second time you make it." "Good judgement comes from experience.  Experience comes from bad judgement." "Wisdom is always wont to arrive late, and to be a little approximate on first possession." "When you hear hoofbeats, think horses, not unicorns." "Fast.  Cheap.  Good.  Pick two." "We see a lot of arses on handlebars around here." - [J Ekdahl]