Q:How can I investigate the resistance of wire and how it changes with the length of the wireCheers

get a multimeter. get long lengths of different gauge (diameter) copper lead wire. for each diameter, measure the resistance. cut 1ft off, measure the resistance, cut 1ft off, measure the resistance, cut 1ft off, etc etc. plot the resistance vs length for each gauge separately. show that the resistance is linear in the wire length in each case. now use the different diameter data to measure the resisitivity of copper. resisitivity rho = R*A/L R = resistance L = length A = cross-sectional area cheers

Q:Hi, I'm extending my pc 5.1 sound system stereo cables. I have a M/F extension wire which I will cut to solder a seamless wire to the system. Problem is that in the system cable I have a white, green(or red) and bare wire. and ont he extension I have a black red and white. Which wire do I connect to which?thanks

It doesn't matter as long as you keep it strait, when ever possable connect a white wire to white wire, red wire to red wire etc...if you have like a green wire original but no green extension wire then I would use green electrical tape to color code the extension wire to the same color as the original, you can buy electrical tape in almost any color and wrap it around the wire and connector ends for color coding...

Q:Can I use 12-2 gauge wire on a 10 amp breaker to wire my light switches,and can I use 10 gauge wire on a 10 amp breaker? For a light fixture

YES ... always use 12gauge with a ground ; 10ga or 8ga is for 220volts .... you should use a 20amp breaker for light switches and a 30amp breaker for the wall plugs ... so as you know [[ to help you understand more about electrics --- the ele

Q:i want to rewire my trailer harness on my truck. i have a 6 wire roung plug but i wat a 7 wire plug. what is the 7 wires for?

1. left turn sig., 2 right turn sig., 3 brake lights. 4 tail lights. 5 ground. 67 electric brake. This is my best guess. But I would buy a shop manual. they pay for themselves.

Q:I just purchased a Pyle Audio aftermarket radio. The wiring is very different actually. It only has 2 single speaker wires (1for each side). So do I hook up multiple wires to one wire or what? I was thinking that I hook up the left front and rear speakers to the left speaker wire and vice versa for the other side. Need some advice.

Do you have a model number, so we can research your radio?

Q:what is the yellow wire, what is the grey wire, and the black

Custom 87 Chevy Truck

Q:What would the wire size be for a 3 phase 4 wire - 480/277V - 400A panelboard. Would it be (3) 600mcm w/ (1) 1/0 ground?

Well not quite: 1. The panelboard is 4 wire therefore the (3) in the description would be (4). The 4th wire is for the neutral and required if you are using the 277. Otherwise the panelboard is a 3 wire board and no 277 2. 600 kcmil copper with 75°C insulation is able to carry 420 A as long as the ambient temperature < 86°F (30°C) and are installed by themselves (not in a raceway/cable tray with other power conductors). If the conductors are aluminum, the temperature is hot, the installation has multiple conductors in the same raceway/cable tray, or the distance is of sufficient length resulting in unacceptable voltage drop, the cable must be derated -- read you must increase the size to 750 kcmil or increase the insulation rating to 90°C The ground conductor should be of sufficient size

Q:is there a way to wire an exit sign to a plug for an outlet receptacle?

Fire codes in most places require it to be hardwired in an emergency circuit or to have a battery back up good for four hours.

Q:I wired an outdoor lamp-post. I tested it before wiring it to the fuse box...and if I touch the lamp-post I feel the current (a slight shock). I will be using a ground fault breaker....so I assume if I wire it to that I am going to loose the connection. Any thoughts on what is wrong?

You likely scratched the wire somewhere. When I did an outdoor shed the wire made a corner on some metal and scratched the insulation. It is a leak rather than hooking up the wrong wire, otherwise you would have gotten more than a tingle. First I would examine everywhere the wire comes in contact with the post. Second Check all the connections to see if some were improperly taped, or the wire was cut when stripping.

Q:When making pc boards with microcontrollers, oscillators, etc.. What is the right kind of wiring to use? Specifically:What material (e.g. copper)?What thickness?What brand?Where to buy?What's the difference between the stiff wire and easily bendable wire?Thanks.

You will almost always use copper. We need more data to give you a good answer. How much current are you going to carry? What frequency signals are you going to carry? Stiff wire is solid and easily bendable is stranded.