{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Final Practice

# Final Practice - Practice Final Exam Physics 1B Name ID...

This preview shows pages 1–3. Sign up to view the full content.

Practice Final Exam Physics 1B —————————————————— Name: —————————————————— ID number: —————————————————— Lecture (1 or 2): Section (A-F): —————————————————— 1. An electron is located in the center of a non-conducting sphere with a uniform charge density ρ . What is the period of oscillations of the electron about the center of this sphere? Solution The electric field as a function of distance r from the center can be computed using the Gauss’ Law: 4 πr 2 E ( r ) = 4 πk 4 3 πr 3 ρ E ( r ) = 4 π 3 ρk r The returning force acting on the electron is F = - eE ( r ) = - 4 πe 3 ρk r, where e = 1 . 6 × 10 - 19 C. The oscillations with this returning force have a period T = 2 π s m e 4 πe 3 ρk = 2 π s 3 m e 4 πkρe , where m e is the mass of the electron. 1

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
2. A charge distribution that is spherically symmetric but not uniform produces an electric field with magnitude E = bR 7
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}