Physics 2020 Exam 2 Review Questions
Dr. Luttermoser’s Class
1. How is emf different from potential difference? What is a load resistance?
2. One can often reduce a complicated circuit to a simple circuit. How do resistors add
in a parallel circuit? And in a series circuit?
3. What is Kirchhoff’s loop and junction rules (note that you will not be asked to solve
problems with Kirchhoff’s rules, but you still need to know there definitions)?
4. What is an RC circuit? What is an e-folding time and how is it related to a capacitor’s
time constant? How does the charge on a capacitor change with time in an RC circuit
(both directions)?
5. Review the summary of Chapter 18 in the textbook and learn the definition of all
boldface terms in this chapter.
6. Review Examples IV-3 (Problem 18.31, RC circuits) in the class notes. Make sure
you understand CAPA Problems 2.1 (reduced resistor) and 2.3 (RC circuit). Finally,
make sure you understand how to do the Supplemental Homework Problem Set 2: 1
(Problem 18.6, reduced resistor) and 3 (Problem 18.32, RC circuit).
7. Describe in detail, the magnetic field of a dipole magnet. How is north and south
defined? What is the orientation of the B-field lines with respect to north and south?
8. What is the force law of a magnetic field? What is the unit of measurement of the
magnetic field (both SI and cgs systems). What is the strength of the Earth’s magnetic
field at the surface?
9. How do we know that the Earth’s magnetic field has changed direction over time?
10. If the magnetic field points out of the page and a negative charged particle moves to
the left in this field, what direction does the magnetic force point? (Use right-hand
rule #1.)
11. How does one determine the torque of a current carrying loop embedded in a B-field?
12. How does a galvanometer work? What does it measure?
13. How do charged particles move in a magnetic field? What is meant by the radius of
curvature?
14. Describe Ampere’s Law. What is a solenoid and how does it work? Describe right-
hand rule #2, the relation between currents in wires, the B-field they generate, and
forces imparted on other charge carrying conductors.
15. How does one determine the direction of the B-field produced by a current flowing
through a wire? (Use right-hand rule #3.)
16. What is meant by magnetic domains? Why are some materials ferromagnetic?
