1. Electricity and Magnetism
Physics 208
Dr. Tatiana Erukhimova
Lecture 3

2. Problem 6 page 10
Suppose a charge were fixed at the origin and an amount of charge Q were uniformly distributed along the x-axis from x=a to x=a+L. What would be the force on the charge at the origin?

3. Another example on force due to a uniform line charge
A rod of length L has a total charge Q smeared uniformly over it. A test charge q is a distance a away from the rod’s midpoint. What is the force that the rod exerts on the test charge?

6. Richard P. Feynman
Nobel Prize in Physics, 1965
From long view of the history of mankind – seen from, say,
ten thousand years from now – there can be little doubt
that the most significant event of the 19th century will be
judged as Maxwell’s discovery of the laws of electrodynamics.
The American Civil War will pale into provincial insignificance
in comparison with this important scientific event of the same
decade.

7. The negative charge of electron has exactly the same magnitude as the positive charge of the proton.
Neutral atom
Positive ion
Negative ion

8. Charging of neutral objects
1) By contact: a) b)
2) By induction (we’ll talk about it a little bit later)

9. How you can make a balloon stick to the wall?

10. Hw Quiz

11. Have a great day! Hw: All Chapter 2 problems and exercises
Reading: Chapter 2