# Physics 2102

Topics: Magnetic field, Electromagnetism, Maxwell's equations Pages: 4 (756 words) Published: March 6, 2013
PHYS 2102
Final Exam
Fall 2008

Name :________________________

Student # : _________________________

Section (circle one):

001 (Dr. Leilabady) 002 (Dr. Astratov)092 (Dr. Aktas)

There are 12 questions, 10 points each
Exam graded out of 100 points (i.e. there is up to 20% bonus opportunity)

This is a closed book exam. I understand I am not to use any notes or information other than on this exam sheet. I may use a pocket calculator but only for the purpose of numerical calculation. I accept the responsibility to know and observe the requirements of the UNC-Charlotte Code of Student Academic Integrity.

__________________Signature

Show all of your work. Do not skip steps. First write down the relevant equations then substitute the numbers if necessary.

DO NOT START TILL INSTRUCTED TO DO SO BY THE EXAMINER

1. Two 1.2 g spheres are charged equally and placed 1.8 cm apart. When released, they begin to accelerate at 245 m/s2. What is the magnitude of the charge on each sphere?

2. For what electric field strength would the current in a 2.0 mm diameter nichrome wire be the same as the current in a 1.0 mm diameter aluminum wire in which the electric field strength is 0.0095 N/C? [Conductivity of Aluminum = 3.5 x 107Ω -1m-1 and conductivity of Nichrome = 6.7 x 105Ω -1m-1]

3. What is the escape speed of an electron launched from the surface of a 1.0 cm diameter plastic sphere that has been charged to +11 nC?

4. The electric potential in a region of space is V = (155x2 - 200y2) V, where x and y are in meters. What are the strength and the direction of the electric field at (2.0 m, 2.2 m)?

5. A battery with an emf of 75 V is connected to the two capacitors shown in Figure. Afterward, the charge on capacitor 2 is 655 µC. What is the capacitance of capacitor 2?

[pic]

6. Consider the circuit in Figure, in which R = 12 [pic]....