   Physics 233. Review for exam I.

1. Chapter 23. Electric Charge.
• Unit: Coulomb
• Unit: C/s=1 Amp (for current, I)
• Charges come in discrete pieces; electrons, protons.
• Ways to charge objects:
• rubbing
• conduction (contact with another charged object)
• induction (bring another charged object close)
• photoionization, chemical dissociation
• Coulomb's Law: • E-field Definition: • Rules of Electric field lines. (eg. never cross)
• Field due to point charge: • Field above or below a Electric Dipole: (SKIP) • Hints for finding E - Shell theorems.
1. E-field outside of a spherically symmetric charge distribution is the same as the E-field of a point charge with the same total charge placed at the center
2. E-field everywhere inside of a shell with a spherically symmetric charge distribution is 0.
• Field Due to Continuous Charge Distributions.
• Line charge, C/m.
• Surface charge, C/m .
• Volume charge, C/m .
• Find or or • Find • Use symmetry to see if some components of are 0.
• Integrate 2. Chapter 24. Gauss' Law.
• Flux, • • .... the integral is over any closed (Gaussian) surface
• A gaussian surface is useful if:
• it is parallel and/or perpendicular to the E-field.
• E = 0 on the surface
• E is constant on the surface
• it intersects the point P where we want to find E
• Examples of E-fields we derived:
• Near a uniformly charged sheet/plane: • Near a conducting plate with the charge density on both sides: • Electric field outside spherical shell of total charge q: • Electric field near a line of charge: 3. Chapter 25. Electric Potential.
• Electric Potential Energy.
• Relative • Absolute and • Units: J
• Electric Potential, .
• Relative • Absolute • Units: J/C or N m/C
• Finding Potential from .
• • Finding from Potential.
• ; ; • When is uniform, • Example: checkpoint 6.
• Potential and Potential Energy Due to Point Charges
• • Example: Question 3, 10.
• • Potential due to continuous charge distributions
• • Potential is constant inside of conductors   