Classification of inductors, PhysicsInductors can be classified on the basis of nature of value and type of core used. Different type of inductors based on the type of core is:AIR CORE INDUCTORS: Air core coils are wound on formers to provide inductance of a few micro-henries. They are used at radio frequencies in tuning coils, interstate coupling coils, etc. The main requirements of such coils are:(1) Stability of inductance under all operating conditions.(2) High ratio of inductive reactance to effective loss resistance at the operating frequency.(3) Low self capacitance.(4) Reasonable size and cost.(5) Low temperature coefficient.