Question

When the ebonite rod is rubbed with fur, the charge acquired by the fur is:
A.Negative
B.Positive
C.Both positive and negative
D.None of these

Answer 1

Hint: Fur is a thick growth of hair that covers the skin of many different animals. It is a defining characteristic of mammals. It consists of a combination of oily guard hair on top and thick underfur beneath.
Static electricity is the result of an imbalance between negative and positive charges in an object. These charges can build up on the surface of an object until they find a way to be released or discharged.
 The two types of electric charge are positive and negative (commonly carried by protons and electrons respectively). Like charges repel each other and unlike charges attract each other. In matter, negative charge is carried by electrons, and positive charge is carried by the protons in the nuclei of atoms.

Complete answer: Ebonite rod is a rod made by special vulcanized rubber. On rubbing the ebonite rod with fur, electrons move from fur to the ebonite rod. The electrons in fur are less tightly bound than electrons in ebonite and hence ebonite gets a negative charge. The charge on ebonite rod is negative and the charge on fur is positive.
Hence, option (B) is correct.

Additional information:Ebonite is blackish brown and firm, but its main raw material is rubber. By mixing and heating rubber and sulphur, they combine and become low-elastic and very firm vulcanized rubber. The name “ebonite” comes from the meaning “ebony”.

Note:
Note that when the glass rod is rubbed with silk cloth. The charge on the glass rod is positive. The best combinations of materials to create static electricity would be to have one material from the positive charge list and one from the negative charge list. Examples include combining human skin with polyester clothes, combing hair with a plastic comb, and rubbing fur on a Plexiglas rod.