Transactions on Machine Design Zaklina J. Mancic, Zlata Z. Cvetkovic, Saša S. Ilic 9 2 2021 https://www.dline.info/tmd/fulltext/v9n2/tmdv9n2_3.pdf Using the image theorem we have prepared bi-isotropic material of Tellegen type for which the expressions for both electric and magnetic scalar potential of the point charge placed in air spherical hollow. It represents a contribution to the electromagnetic analysis of bi-isotropic materials and we have tested the design.