# Physics equations/Previous exams/Second semester calc F2013

## Final exam from Fall 2013

All exams and test will be considered open source after the course ends

Final Exam Fall 2011         Name:

• Do these problems on separate paper. Staple or fold pages in proper order, labeled by problem number.
• Neatly cross out work that you do not wish to be graded (penalties will be result from incorrect statements and equations).
• For a partial credit (at least half) write down the equation and box it before plugging in numbers.
• The value of each question ranges from 5 to 10 points (depending on complexity.)

1. Two point charges are on the x axis (y=0): 2nC are at x=1.5 and 3nC are at x=2.5. Find the electric potential (V) on the y axis at y = 4.0.
2. Repeat the previous problem with the same two charges, but now find the electric potential (V) on the x axis at an arbitrary point, x.
3. Again, with the same two charges, find the electric field (E) at an arbitrary point on the x-axis.
4. A block of carbon is 400m long and has an cross section area of 0.1 m2. What is the resistivity if the resistance, R, is 0.03 Ohms?
5. What is the resistance of a 3 Ohm resistor connected in parallel with a 2 Ohm resistor?
6. Repeat the previous problem, except with the two resistors connected in series.
7. A thin ring of radius a is uniformly charged with a total charge of Q. Find the electric potential (V) on axis, at a distance z from the center..
8. In the figure labeled 'Gauss law pillbox', E2 = 3.5N/C and 3.0E1 = 3N/C. The height Δy is 0.25m, and the radius is 0.5m. How much charge is enclosed?
9. A thin shell of spherical charge has a surface density of σ (Coulombs per square meter). The radius is a. Find the electric field for a distance r from the center, where r > a.
10. Answer the previous question, except now the distance from the origin, r, is less than a.
11. An infinitely long cylinder of radius a has a volume charge density of ρ (C/m3). Using Gauss' law, and showing your steps, find the charge density for r > a
12. Repeat the previous problem for r < a
13. The electric field is E = 4i + 3j. What is the potential difference between the origin and the point on the x axis at x=7?
14. Repeat the previous question for the potential difference between the origin and the point (x,y)=(7,5).