Which of the following is a method of charging an object by direct contact?

Which of the following is a method of charging an object by direct contact?

• A. Friction
• B. Conduction
• C. Induction
• D. Polarization

Answer: (B)

Charging by direct contact is conduction. When a charged object touches a neutral conductor, electrons move freely through the conductor and flow across the contact until both objects reach the same electric potential. The total charge is shared between the two objects, so the previously neutral object ends up gaining a net charge in proportion to how easily charges can distribute between them (often roughly half if the objects are similar in size and shape). This is different from charging by friction, which involves rubbing two materials to transfer electrons, and from induction, which charges a object without any contact by rearranging internal charges in response to a nearby external charge. Polarization is just the slight shift of charge within a neutral object in an external field, not a net transfer of charge.

Charging by direct contact is conduction. When a charged object touches a neutral conductor, electrons move freely through the conductor and flow across the contact until both objects reach the same electric potential. The total charge is shared between the two objects, so the previously neutral object ends up gaining a net charge in proportion to how easily charges can distribute between them (often roughly half if the objects are similar in size and shape). This is different from charging by friction, which involves rubbing two materials to transfer electrons, and from induction, which charges a object without any contact by rearranging internal charges in response to a nearby external charge. Polarization is just the slight shift of charge within a neutral object in an external field, not a net transfer of charge.