Which statement best distinguishes free charge from bound charge?

Which statement best distinguishes free charge from bound charge?

• A. Free charge can move under an external electric field (in conductors); bound charges are induced in dielectrics due to polarization
• B. Free charge is fixed and cannot move
• C. Bound charges are free to move in conductors
• D. There is no distinction between free and bound charges

Answer: (B)

Free charges are those that can move in response to electric forces, while bound charges come from the way atoms polarize in a material and stay attached to their atoms rather than roaming freely. In conductors, electrons are free to drift when an external field is applied, which is why they conduct electricity. In dielectrics, electrons shift slightly relative to the nuclei, creating polarized regions and bound surface charges; these charges are not free to move throughout the material. So the statement that free charge is fixed and cannot move isn’t correct, since free charges can and do move in response to fields, whereas bound charges are localized due to polarization. The notion that bound charges are free to move in conductors is also incorrect, and there is a genuine distinction between free and bound charges.

Free charges are those that can move in response to electric forces, while bound charges come from the way atoms polarize in a material and stay attached to their atoms rather than roaming freely. In conductors, electrons are free to drift when an external field is applied, which is why they conduct electricity. In dielectrics, electrons shift slightly relative to the nuclei, creating polarized regions and bound surface charges; these charges are not free to move throughout the material. So the statement that free charge is fixed and cannot move isn’t correct, since free charges can and do move in response to fields, whereas bound charges are localized due to polarization. The notion that bound charges are free to move in conductors is also incorrect, and there is a genuine distinction between free and bound charges.