In this paper, the magnetic flux density was studied using a mathematical model and different inner radius has been used for the iron free coil. The maximum value of magnetic field and the magnetic scalar potential was calculated. The paraxial ray can be studied using rung Kutta to solve the differential equation in the infinite and zero magnification condition, all results are determined using MATLAB program.

Thermoelectric and thermomagnetic coefficients were calculated for n-type undoped InSb single crystals through a temperature range from 10°C up to 80°C and magnetic fields from -0.6T to 0.6T. The thermoelectric Seebeck coefficient varied only with the temperature gradient, while the thermomagnetic Nernst coefficient varied with both the temperature gradient and the magnetic field. This paper also investigated the effects of the incident angle of magnetic field on the InSb sample surface with regard to the values of thermoelectric and thermomagnetic coefficients; the results showed that thermoelectric and thermomagnetic coefficients were independent of magnetic field direction.