Which type of charging method is NOT considered an active charged media type?

The method classified as non-contact charging is not considered an active charged media type because it relies on the transfer of charge without any physical connection or direct interaction between the charging source and the material being charged. In contrast, the other methods—triboelectric charging, corona charging, and charging by induction—actively involve a physical mechanism or direct interaction to induce charge on a medium.

For example, triboelectric charging involves friction between two different materials, which actively transfers electrons and creates a charge. Corona charging uses a high-voltage discharge to ionize the air around a charged electrode, actively generating ions that can attach to particles. Charging by induction involves bringing a charged object close to a neutral object, causing electrons to redistribute and create a charge on the neutral object through an active interaction.

Hence, non-contact charging stands apart because it does not engage in any direct mechanism of charge transfer, which is why it is categorized differently from the other methods that require active participation to charge the medium.