A metal sphere is placed on an insulating stand... - JAMB Physics 2023 Question
A metal sphere is placed on an insulating stand. A negatively charged rod is brought close to it. If the sphere is earthed and the rod is taken away, what will be the charge on the sphere?
The sphere will remain neutral.
The sphere will have a net negative charge.
The sphere will have a net positive charge.
The sphere will become polarized
1. When a negatively charged rod is brought close to the metal sphere, it induces a separation of charges within the sphere. Electrons in the sphere are repelled by the negatively charged rod and move to the side of the sphere farthest from the rod, leaving the near side with a net positive charge.
2. If the sphere is then earthed (connected to the Earth), electrons will flow from the ground to the sphere, neutralizing the positive charge induced by the rod. After earthing, the sphere will have an excess of electrons and, thus, a net negative charge.
3. When the negatively charged rod is taken away, the sphere retains the excess electrons it gained during earthing, resulting in a net negative charge.
Therefore, the correct option is: The sphere will have a net negative charge.
Add your answer
No responses