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.