1. What are the two main reasons that it was difficult to apply the inverse square law to Newton's universal law of gravitation?

2. Name three of the substances discovered by Michael Faraday.

3. What is the name of the device Faraday used to harness the force of an electric current?

4. When two opposite electric charges face each other, where do the electric lines of force begin and where do they end?

5. Explain how lines of force behave, relative to each other, when they flow through space.

6. Looking at the line forces of a field, how can one tell where the field is stronger and where it is weaker?

7. What is known as flux?

8. If you wanted to prevent an electric field from reaching an object, what could you do?

9. How does the size of a charge affect its electric field?