Electrical Charges and Fields

Question 1

How do you charge an object with friction?

Answer 1

Some insulators when you rub them with another insulator electrons are transferred from one material to the other.

Question 2

What are some examples of charging by friction?

Answer 2

1. Rubbing a polyethene rod and dry cloth transfers electrons to the surface atoms of the rod from the cloth. Polyethene rod becomes negatively charged.
2. Rubbing a Perspex rod with a dry cloth transfers the electrons to the cloth. Perspex rod becomes positively charged.

Question 3

What does the experiment show of the force between two charged objects?

Answer 3

1. When the same type of charge they repel each other.
2. When different types of charge they attract each other.

Question 4

Why do charged objects interact?

Answer 4

These forces exist because a charged object (X) creates an electrical field around itself. A second charged object (Y) also has an electric field around itself. The field of Y exert a and equal and opposite force on X. The forces between the two objects becomes stronger as the between the objects decreases.