1. That varies widely. Depends on make, maintainence, operating conditions etc. Couldn't even make a wild guess.
2. As long as you're on the 12V side of the supply, then yes.
SteveJ
The code system is actually pretty easy. It is simply the height of the rail expressed in thousands of an inch. This system is common over all scales.
SteveJ
Seeing as you're talking gauge 1, I'll assume you mean LGB.
Quoted this from MyLargeScale.com forum.
DIAMETER MEASURED CENTER OF TRACK-TO-CENTER OF TRACK
R1 = 1200 mm = 47.24 inches = 3' 11"
R2 = 1560 mm = 61.42 inches = 5' 1.4""
R3 = 2390 mm = 94.09 inches = 7' 10"
R5 = 4640 mm = 182.68...