Aplastic rod becomes negatively charged when it is rubbed with a piece of wool. how does the rod become charged?
a. electrons move from the rod to the wool.
b. protons move from the rod to the wool.
c. electrons move from the wool to the rod.
d. protons move from the wool to the rod.

C. Electrons move from the wool to the rod.

Explanation:

A body is said to be charged when it has either lack of electrons or excess of electrons.

An atom is a neutral entity as the number of protons are equal to number of electrons. Due to transfer of electrons between two atoms, it becomes charged.

Charging by friction occurs when two bodies are rubbed with each other and electrons transfer from one to another. The body which gains the electrons becomes negatively charged and the one which loses, becomes positively charged.

Here, the rod rubs with the wool and becomes negatively charged. It means electrons would have transferred from wool to the rod and due to excess of electrons, the rod became negatively charged.