<p> RF-1</p><p>Phys1120 Post Exam 3 Review:</p><p>Inductors</p><p>F M = L I (Definition of L)</p><p> d I dF M d I E= - L (from M = L I , = L + Faraday's Law) d t F d t d t</p><p>LR circuits:  I thru L cannot change instantly  In steady state, I = constant, VL = 0 so L acts like a short.  time constant  = L/R</p><p>UM 1 2 Magnetic energy density = uM = = B vol 2m0 1 Magnetic energy of inductor = U= L I2 2</p><p>AC Circuits</p><p>2 Vpeak V(t) = Vpeak sin(t), V= V = rms 2</p><p>All the DC voltage formulas V = I R, P = I V = I2 / R = V2 / R work OK with Irms, Vrms, and Pavg V V N Transformers only work for AC voltages only out= S = S Vin V P N P</p><p>IS VP N P Pout = Pin  IS VS = IP VP  = = IP V S N S</p><p>EM Waves</p><p> Light is an electromagnetic wave which is created by accelerating electric charge.</p><p> Know what a plane wave is.</p><p> l f= c = speed of light = constant , EM spectrum (radio, visible, IR, UV, etc)</p><p> power P  intensity (W/m2 ) = , I = area A</p><p>Phys1120 Notes, Dubson ©University of Colorado at Boulder RF-2</p><p>Ray Optics c  Snell's Law: n1 sinq 1= n 2 sin q 2 , where index of refraction = n = v</p><p> o n1 sinq c= n 2 sin(90 ) = n 2  total internal reflection, critical angle C : 144424443 1  Converging and diverging lenses , focal length</p><p> f > 0 f < 0  Ray diagrams, image formation, real vs. virtual images</p><p> Camera vs. eye</p><p>1 1 1 h d  image/object math: = + , M � i i f do d i ho d o</p><p>Phys1120 Notes, Dubson ©University of Colorado at Boulder RF-3</p><p>Are you ready for the Final Exam? If so, you should know and understand.</p><p> The definition of the electric field.</p><p> The definition of the magnetic field.</p><p> Coulomb's Law.</p><p> The E-field due to a point charge and how to derive it.</p><p> Gauss's Law.</p><p> The definition of electric flux and magnetic flux.</p><p> The definition of voltage difference.</p><p> Voltage due to a point charge and how to derive it.</p><p> The definition of capacitance.</p><p> Kirchhoff's Laws for circuits (voltage law and current law)</p><p> The Biot-Savart Law.</p><p> Gauss's Law for B-fields.</p><p> Faraday's Law.</p><p> The definition of inductance.</p><p> Snell's Law.</p><p>You should invent a problem in which you use </p><p>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.</p><p>Phys1120 Notes, Dubson ©University of Colorado at Boulder</p>