When a person holds a negatively charges metal rod and stands bare-footed on the ground, how will the charges leak?

Analyze the question: A person holds a negatively charged metal rod and stands barefoot on the ground. The question asks how the charge leaks away.

Concept:

• In solids (metals, the human body), only electrons (negative charges) are free to move. Positive charges are fixed in the lattice, so they do not flow.
• The human body is a fairly good conductor, especially with moisture or sweat, so it provides a path to the earth.
• The earth acts as a huge reservoir that can accept or supply electrons.
• Excess electrons repel one another, so they move away from the rod to the region of lower electron concentration, which is the earth.

Solution:

1. The rod has an excess of electrons.
2. The rod is a metal and is in contact with the person's hand, so a conducting path exists: rod → hand → body → feet → ground.
3. The excess electrons repel each other and flow along this path into the ground.
4. The rod becomes neutral, so the charge has leaked away.

Checking the options:

• A. Negative charges flow to the ground through the body. This is correct.
• B. Positive charges do not move in solid conductors. Physically, the same result can be described as electrons leaving, so this is not the right description.
• C. Leakage through air is slow and not the main route when a conducting path is available.
• D. The same reasoning applies. Air is a poor conductor, so it is not the main leakage path.

Answer: A. The electrons flow from the rod through the person's body to the ground.

Exam tip: In solid conductors, remember that "only electrons move." Whenever a charged conductor is connected to the earth through a conducting body, a negative charge flows to earth, and a positive charge is neutralized by electrons flowing up from earth.