Slide 1Some adviceWhat are we going to learn? A road mapExam 2Current and resistanceCircuitsResistors in series and in parallelRC circuitsMagnetic FieldsMagnetic forces and torquesInduced fieldsFormula sheet – IFormula sheet - IIPhysics 2102 Exam 2: review sessionPhysics 2102Gabriela GonzálezExam stress doesn’t help!! Look up strategies for managing exam stress.2Some advice Mild (~low C): –revisit homework sets; –revisit your quizzes;–read chapter summaries; –read formula sheetPHYS 2102Sleep well, and save some time to relax before the exam!!PHYS 2102Medium (~C): read class slides; revisit class problems; do all checkpoints,solve ~1/2 questions; read all problems;solve a few old examsPHYS 2102Hot (~B): read whole chapters; solve all questions; solve ~1/2 problemssolve many old examsPHYS 2102Tabasco hot (~A!): solve ALL problems, invent new problems solve all old examsWhat are we going to learn?A road map•Electric charge •Electric force on other electric charges•Electric field, and electric potential•Moving electric charges : current •Electronic circuit components: batteries, resistors, capacitors•Electric currents• Magnetic field •Magnetic force on moving charges•Time-varying magnetic field •Electric Field•More circuit components: inductors •All together: Maxwell’s equations•Electromagnetic waves •Optical images•Matter wavesExam 2•(Ch 26) Current and Resistance: current, current density and drift velocity; resistance and resistivity; Ohm’s law. •(Ch 27) Circuits: emf devices, loop and junction rules; resistances in series and parallel; DC single and multiloop circuits, power; RC circuits. •(Ch 28) Magnetic Forces: magnetic and electric forces on a point charge; magnetic force on a current-carrying wire; magnetic torque on a magnetic dipole.•(Ch 29) Magnetic Fields due to Currents: Biot-Savart’s law and Ampere’s law; forces between currents; solenoids; magnetic dipoles.•(Ch 30.1-5): Induction and Inductance: Faradays’ law, Lenz’s law.Current and resistancei = dq/dtr = r0(1+a(T-T0))R = rL/AJ=nevdCircuitsSingle loopMultiloopV = i RP = iVLoop ruleJunction ruleResistors in series and in parallel Resistors CapacitorsKey formula: V=iR Q=CVIn series: same current same charge Req=∑Rj 1/Ceq= ∑1/Cj In parallel: same voltage same voltage 1/Req= ∑1/Rj Ceq=∑CjRC circuitsTime constant: t=RCCharge is 63% of final charge, or 37% of initial charge( )/( ) 1t RCq t C e-= -E/0( )t RCq t q e-=/0( )t RCdqi t i edt-= =VC(t)=q(t)/C; VR(t)=i(t)RMagnetic Fields•Magnetic fields are created by magnetic materials or by electric currents.•Magnetic field lines: always closed!•Magnetic fields created by currents: wires, loops, solenoids (Biot-Savart’s law, Ampere’s law)•Magnetic dipoles: field produced by a dipole-CIldB0304 rrlidBdMagnetic forces and torquesF qE q v B= + �r r rrBLdiFdBU Bt mm= �=-rr rrrgLvFqBmvr BLiFInduced fieldsChanging magnetic flux creates an induced electric field (and a current if there is a wire!): Faraday’s lawdtdldEBCFormula sheet – IFormula sheet -
View Full Document
Unlocking...