I want to make a helmholtz coil to create magnetic field about 100 Gauss. I tried searching over Internet as well. I will be using 18 gauge copper wire to make coils of radius 15 cm. It'd better if I could produce required magnetic field with less turns by increasing current. But there is problem with power loss as well. So could anyone help me with the calculation,like how many turns with max current flow would help me to get the field?what should be the voltage applied to the wire?