Iron Core Inductor

In the areas where low space inductors are in need then these iron core inductors are best option. These inductors have high power and high inductance value but limited in high frequency capacity. These are applicable in audio equipment’s. When compared with other core indictors these have very limited applications.
Air Core Inductor

By taking a cylindrical material of specific diameter (like a drill bit) as a template, we can wrap around a length of wire to make an air-core inductor, further the inductance can be stabilized by dipping the inductor in varnish or securing it by wax.
The core material is air, so it has low permeability hence lower inductance so, it can be used for high-frequency applications.
Ferrite Core Inductor

Mixing Iron oxide (Fe2O3) in combination with other metal oxides like (Mn), zinc(Zn) or magnesium(Mg) at a temperature of 1000° C – 1300° C will result in a material with very interesting magnetic properties called ferrite.
Ferrite core inductors have high permeability, high electrical resistivity and low eddy current losses these characteristics make them suitable for many high-frequency applications.
Bobbin Inductor
Winding a length of wire in a specially made cylindrical bobbin and securing it with a shrink tube forms a bobbin inductor.
The core material is ferrite so, the properties are also similar to a ferrite core inductor. The small size makes them suitable for power adapter like applications.
Variable Inductor

It is formed by moving the magnetic core in and outside of the inductor windings. By this magnetic core we can adjust the inductance value. When we consider a ferrite core inductor , by moving its core inside and outside on which the coil is wounded , variable ferrite core inductor can be formed.
These type of inductors are used in radio and high frequency applications where the tuning is required. These inductors are typically ranged from 10 μH to 100 μH and in present days these are ranged from 10nH to 100 mH.
Shielded Surface Mount Inductor

It is built by winding a length of wire in a cylindrical bobbin and securing it in a specially made ferrite housing forms, shielded surface mount inductor.
These inductors are specially designed for PCB mounted applications and the shielding is there to reduce EMI and noise from the inductor and also to be able to use in a high-density design.
Toroidal Inductor
Wire wounded on core which has ring or donut shaped surface. These are generally made up of different materials like ferrite, powdered iron and tape wound etc. This inductor has high coupling results between winding and early saturation.
Its arrangement gives minimum loss in magnetic flux which helps to avoid coupling magnetic flux with other devices. It has high energy transferring efficiency and high inductance values at low frequency applications. These inductors mainly used in medical devices, switching regulators, air conditioners, refrigerators, telecommunications and musical instruments etc.
Multilayer Chip Inductors
The name itself indicates that it consists of multilayers. It is built by using thin plates made out of ferrite. The coil pattern is printed on it, with special metallic paste (recipe confidential to manufacturer), proper placement of these sheets a layer after another forms a coil hence inductance.