Question

E. Make a new Band Tpair. Mark them with the appropriate sign ( + or -). Obtain a glass rod and a piece of silk. Rub the glass rod with the piece of silk, and then bring it close to, but not touching, the Btape and then bring it close to T.

- What additional comments should be made? Why would you say that the glass rod does not have a negative charge?

- How could we determine whether or not there are any other kinds of charge in addition to the positive or negative charge?

- What would your group say is the meaning of neutral charge?

- How did the T-tape get a different kind of charge than B-tape?

- How did the neutrally charged rubber rod get its negative charge when rubbed with fur?

- Why are the two kinds of charge called positive and negative?

Answer 1

(1) When you are rubbing the glass rod with the silk cloth, electrons are stripped away from the atoms in the glass and transferred to the silk cloth. This leaves the glass rod with more positive than negative charge, so you get a net positive charge.

(2) As we know like charges repel each other and opposite charges attract , So we can use this concept to find if some other form of charge is present. Say their is some other charge X( just a name ) . And you try to find its pair but at the end what we got to know only three types of charges exist positive,negative,neutral.

(3) A neutral charge is a case when we have equal number of positive and negative charges . So all of them cancel each other.

(4) T and B got different sort of charges as one of had more tendency to loose electrons than the other , So one which preferred loosing electrons became positively charged and other one negatively charged.

in order to understand more on this please go through it:

Triboelectricity, the transfer of charge between two objects by means of friction, depends on the varying affinities that different materials have for electrons. When you rub two materials together, the material that has the stronger affinity for electrons pulls them from the other material.

(5)when an rubber rod is rubbed against animal fur, some of the electrons from atoms of the fur are transferred to the rod. The rubber rod becomes negatively charged, and the fur becomes positively charged.

(6)Benjamin Franklin coined the terms +ve and -ve charges in the late 80s due to the fact that when equal amounts of the two different charges (+ve and -ve) were added (or present in a body), they cancelled each other i.e. it was as if there was no charge (it is universally accepted that when a positive integer is added with a negative integer of same magnitude, the resultant is zero).