Question

a 1\ trade size rmc conduit has an outside diameter of______. a. 1.163\ b. 1.660\ c. 1509\ d. 1.315\

Explanation:

To determine the outside diameter of a 1" trade size RMC (Rigid Metal Conduit), we refer to standard electrical conduit sizing tables. For 1" trade size RMC, the outside diameter is a known standard value. From electrical engineering standards, a 1" trade size RMC has an outside diameter of 1.315". Wait, no, correction: Wait, actually, let's recall the correct values. Wait, no, the correct outside diameter for 1" RMC (rigid metal conduit) is 1.315"? Wait, no, maybe I confused. Wait, no, let's check the standard. The National Electrical Manufacturers Association (NEMA) and NEC (National Electrical Code) standards: For 1-inch trade size RMC, the outside diameter is 1.315 inches? Wait, no, another source: The outside diameter of 1" RMC is 1.315". Wait, but let's check the options. Wait, option D is 1.315", option A is 1.163" (which is for 3/4" maybe), option B 1.660" (maybe 1-1/4"), option C 1.509" (maybe 1-1/8"). Wait, no, actually, the correct outside diameter for 1" trade size RMC is 1.315", so the correct option is D? Wait, no, wait, I think I made a mistake. Wait, let's check again. Wait, the standard outside diameter for 1" RMC (rigid metal conduit) is 1.315 inches. So the correct option is D: 1.315".

Wait, but let's confirm with the NEC or conduit sizing. The trade size and outside diameter:

• 3/4" trade size RMC: OD 1.163"

• 1" trade size RMC: OD 1.315"

• 1-1/8" trade size RMC: OD 1.509"

• 1-1/4" trade size RMC: OD 1.660"

Yes, so for 1" trade size RMC, the outside diameter is 1.315", which is option D.

Answer:

D. 1.315"