RF-1 Phys1120 Post Exam 3 Review: Inductors (Definition of L) MLIΦ = dILdt= −E (from , MLIΦ =MdLdt dtΦ=dI + Faraday's Law) LR circuits: • I thru L cannot change instantly • In steady state, I = constant, VL = 0 so L acts like a short. • time constant τ = L/R Magnetic energy density = 2MM0U1uBvol 2µ== Magnetic energy of inductor = 21UL2= I AC Circuits V(t) = Vpeak sin(ωt), peak2rmsVVV2== All the DC voltage formulas V = I R, P = I V = I2 / R = V2 / R work OK with Irms, Vrms, and Pavg Transformers only work for AC voltages only out S Sin P PVVVVN==N Pout = Pin ⇒ IS VS = IP VP ⇒ SPPPSIVNIV==SN EM Waves • Light is an electromagnetic wave which is created by accelerating electric charge. • Know what a plane wave is. • , EM spectrum (radio, visible, IR, UV, etc) f c speed of light = constantλ == • 2power Pintensity (W/m ) = , Iarea A= Phys1120 Notes, Dubson ©University of Colorado at BoulderRF-2 Ray Optics • Snell's Law: , where index of refraction = 11 2nsin nsinθ = θ2cnv= • total internal reflection, critical angle θC : ns o1c 2 21in n sin(90) nθ ==• Converging and diverging lenses , focal length f < 0 f > 0 • Ray diagrams, image formation, real vs. virtual images • Camera vs. eye • image/object math: oi11fd=+1d , iioohdMhd≡ = Phys1120 Notes, Dubson ©University of Colorado at BoulderRF-3 Are you ready for the Final Exam? If so, you should know and understand. • The definition of the electric field. • The definition of the magnetic field. • Coulomb's Law. • The E-field due to a point charge and how to derive it. • Gauss's Law. • The definition of electric flux and magnetic flux. • The definition of voltage difference. • Voltage due to a point charge and how to derive it. • The definition of capacitance. • Kirchhoff's Laws for circuits (voltage law and current law) • The Biot-Savart Law. • Gauss's Law for B-fields. • Faraday's Law. • The definition of inductance. • Snell's Law. You should invent a problem in which you use To prepare for any exam: • Study the online lecture Notes. • Review Concept Tests, CAPA problems, and Tutorial HW. (Read question and try to remember reasoning that gets to the answer) • Prepare your formula sheet. Prioritize: which are the important equations? • Take the practice exam. • It is no good to memorize answers. You have to understand and remember how you got the answers. Phys1120 Notes, Dubson ©University of Colorado at
View Full Document