I would use AWG # 4 copper.
For a 75 amp circuit with a 100 ft run, you would need a #4 AWG copper wire to ensure minimal voltage drop and to meet electrical code requirements. Using the correct wire size helps maintain the efficiency and safety of the circuit.
AWG # 10 wire on 30 amp circuit.
The ground wire in a two or three conductor #12 cable is a #14 bare ground wire.
The size of the wire is set by the maximum current it has to carry. The voltage sets the size of the insulation. In the UK a 230 v (nominal) ring-circuit supplying a set of power sockets is rated at 30 amps and uses a ring of 2.5 sq-mm cable.
For a 70 amp service at 240 volts, you would typically use a wire size of 4 AWG copper wire. This wire size is suitable for carrying 70 amps of current safely over a 240 volt circuit. Be sure to consult local electrical codes and regulations to ensure compliance with requirements in your area.
For a 20 amp circuit, a 12-gauge copper ground wire is typically recommended. This wire size can safely handle the current and provide proper grounding for the circuit.
AWG # 10 wire on 30 amp circuit.
The wire size depends on how much current it will conduct.
Use 8 gauge wire.
# 3 gauge
If it is a 110 volt light it can safely run on a 20 amp circuit with AWG # 12 wire.
Depends on the size of the circuit which you did not list.
Wire size is governed by amperage not voltage. Voltage is an insulation factor when talking about wire. Add up the amperage of fixtures you want in the circuit. Once that is found then the size of the wire can be calculated.
The ground wire in a two or three conductor #12 cable is a #14 bare ground wire.
A 500 MCM copper conductor will limit the voltage drop to 3% or less when supplying 350 amps for 150 feet on a 208 volt system.
The size of the wire is set by the maximum current it has to carry. The voltage sets the size of the insulation. In the UK a 230 v (nominal) ring-circuit supplying a set of power sockets is rated at 30 amps and uses a ring of 2.5 sq-mm cable.
For a 70 amp service at 240 volts, you would typically use a wire size of 4 AWG copper wire. This wire size is suitable for carrying 70 amps of current safely over a 240 volt circuit. Be sure to consult local electrical codes and regulations to ensure compliance with requirements in your area.
For a 20 amp circuit, a 12-gauge copper ground wire is typically recommended. This wire size can safely handle the current and provide proper grounding for the circuit.