Question

When a glass rod is rubbed with a silk cloth, it acquires charge because:
A. electrons are added to it
B. electrons are moved from it
C. protons are added to it
D. protons are removed from it

Answer 1

Hint: Friction is one of the methods of charging a material. When we rub the silk cloth against the glass rod, due to friction between the glass and the cloth there is the transfer of electrons. As a result, both the materials attained a charge.

Complete step-by-step solution:
Let us first understand some points above the charge. A charge is the property of a particle due to which the particle interacts with electric fields and magnetic fields.
The fundamental charged particles are electrons and protons. We know that an atom is made up of protons and electrons. The protons along with some neutrons make up the nucleus of the atom and the electrons revolve around the nucleus.
When the number of protons and the number of electrons in a material is equal then we say that the material is neutral.
When the electrons in a material are more than the protons, the material is negatively charged. This can be done by adding extra electrons from the material.
Whereas when the material has a deficiency of electrons, the material is positively charged. This can be done by removing electrons from the material.
Hence, we say that material is charged.
One of the methods to charge material is by friction. That is why when we rub a silk cloth on a glass rod, there is a transfer of electrons from the glass rod to the silk cloth. As a result, the glass rod becomes positively charged and the silk cloth becomes negatively charged.
Therefore, when a glass rod is rubbed with a silk cloth, the rod attains a charge because some electrons are removed from it.
Hence, the correct option is B.

Note: In two of the options it is given that the glass rod becomes charged because of the transfer of protons. However, protons cannot be removed or added to an atom. This means that transfer of protons is not possible. Only the transfer of electrons is possible.
Therefore, material charges due to the transfer of electrons only.