Excess charge is placed on a metal sphere standing on an insulating stand. Where does that charge settle?
ASpread over the outer surface
BPacked at the point of contact
CLocked inside the centre
DShared with the air around it
Answer & Solution
Correct answer: A. Spread over the outer surface
1. A metal is a conductor, so its charge carriers are free to move through it.
2. All the excess charges carry the same sign, and like charges repel each other.
3. Each charge pushes the others as far away as it can get.
4. The result is that the charge spreads out over the outside surface of the object.
5. On a sphere the shape is regular, so the spread is even all the way round.
6. Charge staying at the point of contact is what happens on an insulator, not on a conductor.
7. For irregular shapes the charge concentrates near sharp points, which is why buildings carry lightning rods.
_Source: Siyavula Physical Sciences Grade 10 (Everything Science, CC BY 4.0), Chapter 16: Electrostatics_
Related questions
How is the magnitude of the electric field at a point defined?Two positive charges of equal magnitude are fixed a short distance apart. A positive test An isolated negative point charge sits alone in space. Which way do its electric field linThe separation between two point charges is doubled while the charges themselves stay the Two small spheres both carry negative charge and are held near each other. What do they doHow does a neutral object become negatively charged?On the axial line of a short dipole the electric field is $E_a$, and on the equatorial linA charge $q$ is enclosed by a closed surface immersed in a medium of relative permittivity