You will need a 40 amp breaker using AWG # 8 wire running it a distance of no more than 50 feet.
If you mean 2/0 copper wire it is rated 175 amps. # 2 wire is 115 amps. If you are referring to 2.0 metric it is rated 15 amps.
A #6 copper conductor with an insulation factor of 75 or 90 degrees C both have an amp rating of 65 amps. If the #6 conductor is connected to a breaker having a 90 degree C rating then the conductor can carry an amperage of 75 amps
10 amps
For service sizes of 100 amps and less a #8 bare copper conductor is required.
A 350 MCM copper conductor with an insulation rating of 90 degree C is rated at 350 amps.
A # 14 copper conductor will be fine to carry 8 amps at 120 volts. This size conductor is rated at 15 amps.
AWG # 6 copper
#8 RW 90 degree wire
# 8 RW90
Service wire required is AWG # 3/0 copper.
If you mean 2/0 copper wire it is rated 175 amps. # 2 wire is 115 amps. If you are referring to 2.0 metric it is rated 15 amps.
A #16 copper conductor is not a wiring size that is used in homes. This is because the smallest breaker for residential use is rated for 15 amps. A #16 copper conductor is only rated at 13 amps. For a load of 13 amps over 100 feet a #12 copper would be required.
Each hot leg to the neutral wire of the service has the ampacity of 200 amps, that is why 3/0 wire is required. A 3/0 copper wire with an insulation factor of 90 degrees C is rated at 210 amps.
10 AWG copper.
Couple of things wrong here. 30 isn't a wire size. If you mean a wire that can carry 30 amps that would be # 10. Now it depends on how many # 10 wires you want to put into a conduit that governs the size of the conduit.
A #3 copper wire with an insulation factor 90 degree C is rated at 105 amps.
Copper is a better conductor by weight, but aluminum is better by weight, so the copper will be thinner but heavier. You will see that a 250 kcmil aluminium wire will get you 170 amps at 60 degC while a 000 (or 3/0) copper wire will get you 165 amps at 60 degC. I think you mean circular mils, not square millimeters.