Question

When an ebonite rod is rubbed with fur, the fur develops a charge which is:
(A). Positive
(B). Negative
(C). Neutral
(D). None of these

Answer 1

- Hint: When two bodies are rubbed against one another electrons can be transferred from one body to another.

Complete step-by-step solution -

When an ebonite rod which is a rubber rod is rubbed against the fur leads to the production of static charges. We all know that rubber is an insulator and will not have charges on it. But when this rubber rod is rubbed with the fur, the electrons which are present in the atoms of the fur are stripped out due to friction in rubbing the two surfaces. The electrons which come out of the fur are distributed on the surface of the ebonite rod.
The surface of the ebonite rod gains a negative charge due to the incoming electrons. While the fur gains a positive charge because there are more protons in the fur compared to the electrons. So the fur gains a positive charge from the rubbing.
So the answer to the question is (A) – Positive

Additional Information:
There are other ways to produce static charges, some of them are,
Heat-induced - Uses heat to produce static charges.
Charge- induced – Uses electrostatic induction to produce static charges
Pressure-induced - Uses pressure to produce static charges.

Note: Electrons are one of the fundamental particles which make up an atom. It has a negative charge whose value is $1.6\times {{10}^{-19}}$coulombs. Electrons in classical terms are a particle of mass $9.1\times {{10}^{-31}}$kg.