Your knowledge of electricty

F-14 Ace · **on:** March 25, 2009, 12:55:52 AM

I am currently studying at a tech school to become an electrician and just wanted to show of the stuff I've learned. Part of the job is to be able to troubleshoot circuits of all kinds. Troubleshooting requires a basic understanding of the principles of how electricity. Just for fun, I will show you a series of diagrams I have created and let you see if you can figure out what is wrong. This isn't too hard if you know how the stuff works.

In this first section, I will show three diagrams and let anyone see if they can figure out what is wrong.

Figure 1
There is something horribly wrong with this circuit. It will not function in its current state. See if you can figure out what the problem is.

Figure 2
Some fool doesn't know how to use their amp meter properly. An amp meter is a device used to measure electric current in a circuit. To measure ampage, you must attach your meter to th circuit using test leads and allow the current to flow through the meter. See if you can figure out why this will probably end badly for whoever is trying to measure current in this circuit.

Figure 3
Here is a circuit with three 100 watt bulbs in series. While this is technically a functional circuit with current flowing through it properly, only the first bulb is lit. The other two are not.
Note: The lightbulbs are all in working order. None of the lightbulbs are burned out. This one will require a more detailed understanding of electricity and the laws and mathematics behind it.

action9000 · **Reply #1 on:** March 25, 2009, 01:53:57 AM

My guesses here:
Ignore if you don't want to read.

F igure 1:
A short circuit.

Figure 2:
An ammeter has (effectively) no resistance so it causes a short circuit.

(Behaves exactly like figure 1)

Figure 3:
I think the voltage drop over the first light bulb is so great that there isn't enough voltage (and therefore not enough current) to light the other two bulbs, correct?

It's a calculation using resistance, voltage and power.

landbeforetimelover · **Reply #2 on:** March 25, 2009, 02:01:50 AM

Oh god. I don't know that much about electricity. I used to back in the days when I really studied everything about computers, but if I were to take the A+ certification test, this is definitely something I'd have to research again. I know all the basic stuff I need to use in everyday life such as how not to get killed while reaching inside the computers and why the PSU can give you a pretty nasty shock if you stick something inside of it (even when it's unplugged and not in a computer any longer), but other than the information I really needed, it's all gone.

If I wasn't such a lazy tech, I'd know why PCI e16 is faster than PCI....but that doesn't really matter to me anymore. It's faster, it's better. That's all I need to know.

Littlefoot1616 · **Reply #3 on:** March 25, 2009, 07:23:58 AM

Corr...flip! Never thought I'd stepping into a classroom environment again after all these years

Figure 1: I would assume this would display a short circuit. Effectively, you've got a parallel circuit and (if memory serves me right back from school days) electricity flows down the path of least resistance. Since the load (lamp) offers resistance to the circuit, not enough current is running to the lamp to light it. Hence the diagram is technically incorrect

Figure 2: I'm gonna say that the ammeter's in the wrong place. If what I said in figure 1 is correct and electricity flows along the path of least resistance, it will flow through the ammeter instead of the lamp (a short circuit effectively). So, therefore the lamp will not light.

Figure 3: With a series circuit, which ever load is closest to the power source will take maximum voltage it requires in order to work. Whatever is left (as an analogy) will continue down the circuit and be used by whatever else is linked to the circuit. So, obviously, the first load has taken what it needs to work but has left minimal or no voltage required to power the other loads of the circuit. Hence why they won't light up

Well that was a blast from the past. If I don't score well, will I have to stay behind after school and do lines until I get it right

Cancerian Tiger · **Reply #4 on:** March 25, 2009, 11:58:53 PM

Hmm...the only things I know about electricity are:

*Do not ever place one of your hands on the (sorry, I forgot the true name of it) harddrive and touch the modem at the same time with your other hand. You'll regret it

! ZAP!

*Never stick a screwdriver in an outlet unless the fuse is switched off.

*Never work on jacuzzi wiring while folks are in the jacuzzi. Somebody posthumously got a Darwin Award for that

!

*How to replace a light fixture. No blonde jokes, por favor

:.

*How to hook up video game consoles. Necessary survival skill

!

That's about all I can think of for now. Oh, one last bit o' wisdom I gained from actually witnessing the following: Never work with wallpaper glue over a hot lightbulb

!

Malte279 · **Reply #5 on:** March 26, 2009, 05:31:49 AM

I lack the technical terms and real knowledge about electricity but I guess my guesses would have come close to what Tim already said. As a child I took a rather risky interest in electric outlets and I must have really had a flock of guardian angels with me as at three years I survived not one or two but three electric shocks as a result from that curiosity. Curiosity is a euphemism for plain stupidity I think. After I got shocked pricking the outlet with my bare fingers (still wonder how I managed to do that. Outlet holes are broader in Germany than in the US, but I don't suppose my fingers were that thin), I used a straw next time, and for the final time a needle. One should expect a kid to learn better from pain, shouldn't one?
I really wonder how I got away with it alive and without any lasting damage... hm, maybe I should make a test about this. Where is the next paper clip?

raga · **Reply #6 on:** April 05, 2009, 10:32:13 AM

Unfortunatly I'm just starting current electricity in phyics, so I can't answer these yet. I could tell you were to place an electron between a 2e-9 C charge and 3e-9 C charge set 2 meters apart so it won't move but once that electron starts flowing across a wire, you lost me. I do know its called an ammeter and not an ampmeter though

lbt/cty_lover · **Reply #7 on:** April 06, 2009, 12:02:35 AM

Don't know about the technical side of electricity, but I do know some practical uses of it. I can program a robot to dance in the dark, for example. I can also make a few neat things with a 555 integrated circuit.