A positively charged glass rod is brought close to a neutral sphere that is supported on a nonconducting plastic stand. Sketch the distribution of charges on the sphere if it is made of:

a) Aluminum
b) Non-conducting plastic

a)Aluminum: the electrons in the sphere would rise towards the positively charged glass rod making the top part of the sphere negative and the bottom part positive

b) Non conducting matierial: nothing would happen the sphere would still be neutral

a) Aluminum:

When the positively charged glass rod is brought close to the neutral aluminum sphere, the electrons in the aluminum will be attracted to the rod. This will cause a redistribution of charges on the surface of the sphere.

Initially, the aluminum sphere will have an equal number of positive and negative charges, resulting in a neutral overall charge.

As the glass rod is brought close, the positive charges on the glass rod will attract the negative charges (electrons) in the aluminum sphere. Thus, the electrons will move towards the side of the sphere closer to the glass rod.

The distribution of charges on the sphere will be such that the side closer to the glass rod will have a surplus of negative charges, while the side away from the glass rod will have a relative deficit of negative charges. However, it is important to note that since aluminum is a good conductor, the charges will distribute evenly on the surface of the sphere.

b) Non-conducting plastic:
In the case of a non-conducting plastic sphere, the redistribution of charges will be different compared to aluminum. Non-conducting plastics do not allow the movement of electrons as easily as conductors do.

When the positively charged glass rod is brought close to the neutral plastic sphere, the electrons in the plastic will not be able to move freely like in a conductor. Consequently, the redistribution of charges will be minimal.

In this case, the plastic sphere will not have a significant distribution of charges. It will remain mostly neutral, with only a slight attraction of electrons towards the side closer to the glass rod. However, since the plastic does not facilitate the movement of charges, the distribution will not be as pronounced as in a conductor like aluminum.

To summarize, the positively charged glass rod will attract negative charges in both cases. However, in a conducting material like aluminum, the charges will distribute more evenly on the surface of the sphere, while in a non-conducting material like plastic, the distribution will be minimal.

a) Aluminum:

When the positively charged glass rod is brought close to the neutral aluminum sphere, the free electrons in the aluminum will redistribute themselves due to the influence of the electric field from the glass rod.

In metals like aluminum, the electrons are free to move around within the crystal lattice. Since the glass rod is positively charged, it will exert an attractive force on the negatively charged electrons in the aluminum sphere. As a result, the electrons in the aluminum will be attracted towards the side of the sphere closest to the glass rod.

This movement of electrons towards one side of the sphere will lead to an accumulation of negative charge on that side. Conversely, the opposite side of the sphere will experience a relative lack of electrons, resulting in a positive charge. Thus, the distribution of charges on the sphere will be such that the side facing the glass rod will be negatively charged, while the other side will be positively charged.

b) Non-conducting plastic:
In non-conducting materials like plastic, the electrons are tightly bound within the atoms and do not move freely. Since they are not free to move, the positive charge on the glass rod will not have any significant influence on the distribution of charges on the plastic sphere. Therefore, the charges on the plastic sphere will remain neutral, and there will be no noticeable redistribution of charges.

However, it is worth noting that some plastics can become slightly polarized under the influence of an electric field, resulting in a weak separation of positive and negative charges. This effect is known as dielectric polarization. But in the case of non-conducting plastic, the polarization effects will be very minimal and not significant enough to cause the redistribution of charges on the sphere.