A #4 copper conductor will limit the voltage drop to 3% or less when supplying 20 amps for a distance of 250 feet at 120 volts.
The ground wire in a two or three conductor #12 cable is a #14 bare ground wire.
No !
In the US and Canada, 10 Guage wire will suffice
White.
It should work okay.
The ground wire in a two or three conductor #12 cable is a #14 bare ground wire.
If it is a 110 volt light it can safely run on a 20 amp circuit with AWG # 12 wire.
No !
In the US and Canada, 10 Guage wire will suffice
White.
It should work okay.
No. The 240V lamp will pop the circuit or fuse because the draw is higher than the supply.
NO - that is dangerous.
A breaker is based on wire size, as the breaker protects the wire and not the load. This is a voltage drop question. A #3 copper conductor will limit the voltage drop to 3% or less when supplying 60 amps for 110 feet on a 110 volt system.
No. You need to rewire the circuit from the electric panel.
The size breaker you use is determined by the size wire used in the circuit. If you use AWG #12/2 wire then use a 20 amp breaker. If you use AWG # 14/2 then use a 15 amp breaker.
You need a step-up transformer, to go from 110 to 220-240 volts. Then a 110 volt supply can operate 240 volt equipment.