What flows to the positively charged conductor by connecting it to the earth?

Analyze the question: A conductor is positively charged. It is then connected to the earth (grounded). What particle moves?

Concept: In solids, including metal conductors, only free electrons can move. Protons and neutrons are held inside the nucleus and cannot flow. Ions in a solid metal lattice are fixed in position.

A body becomes positively charged when it has lost electrons, so it has more protons than electrons. That means it has a deficit of electrons.

Solution:

1. The conductor has a deficit of electrons, so it is positively charged.
2. The earth is a huge reservoir of electrons and is treated as electrically neutral, with a potential of zero.
3. When the conductor is connected to the earth, electrons flow from the earth to the conductor.
4. This neutralises the positive charge on the conductor.

Checking the other options:

• Ion: Ions are not free to move in a solid metal conductor.
• Neutron: Neutrons have no charge and stay in the nucleus.
• Proton: Protons are fixed in the nucleus and never flow in conduction.

Exam tip: In solid conductors, only electrons move. Remember: positive charge = electron shortage, so electrons flow in from the earth. Negative charge = electron excess, so electrons flow out to the earth.