very good, in fact excelent
Look for a copper or metallic woven strap - that will be a good ground The wiring harness includes a ground wire for an amp. Atleast mine did, I got it at circuit city.
Yes, if it is not an insulated wire. If it is bare copper it is always ground. But the hot and neutral wire are also copper, they are just insulated.
A positive plane is just like any other artwork layer - it shows where copper will be. A negative plane, like the name suggests, shows where there will not be copper.
on the ground
copperclad is steel with copper over it steel will drive into the ground and push small rocks out of its path copper doesnt rust but is soft copper will last far longer copper clad takes the good parts of both you can bury a copper plate for lower impedance
In the ground really
Copper is an element. It is a natural mineral found in the ground. It is extracted from the ground by mining similar to the mining of gold or iron.
If you mean 2 bare copper wires those are the ground wires. Tie them together and then connect the light fixture ground wire which will be green or bare copper to those ground wires.
If you mean a bare copper wire, that is the "ground" wire.
Both - you fly it in the air, but you drive it on the ground.
As nuggets, on the ground.
A ground plane is use in radio where the wave length is less than 1 half wave. It produced a false ground (Earth plane) making an image of a 1/4 wave signal reflect on to the aerial creating a half wave image. This improves the efficiency or the aerial, extending it's range. Ground planes are used when the wavelength if the aerial is short or when the earth does not provide a good enough electrical path to ground. They can also be used to distort the polar pattern of the signal.