Analysis of Exact and Approximating Dependences of the Active Resistance of Conductor on the Frequency of Current Under the Action of Skin Effect. - Yakiv Scherbak; Oleksandr Plakhtii; Volodymyr Nerubatskyi; Denys Hordiienko; Dmytro Shelest; Yuryi Semenenko (EUROCON, 2021)