National Electrical Code Articles and Information

1. The minimum size is 3/8 inch, or size 12 metric, pipe size [410.62(A)].
   
2. No, but only if the exposed cord is suitable for hard-usage or extra hard-usage and that cord is not longer than what's needed for the maximum adjustment [410.62(B)].
   
3. Yes, or you could use a busway plug [410.62(C)].
   
   
4. Not normally. But there are three circumstances in which you can [410.64(A), (B), and (C)]. For example, luminaires identified for through-wiring.
   
5. The rating has to be at least 90 DegrC, unless supplying a luminaire marked as suitable for a different insulation temperature [410.68].