Jump to a New ChapterIntroduction to the SAT IIIntroduction to SAT II PhysicsStrategies for Taking SAT II PhysicsVectorsKinematicsDynamicsWork, Energy, and PowerSpecial Problems in MechanicsLinear MomentumRotational MotionCircular Motion and GravitationThermal PhysicsElectric Forces, Fields, and PotentialDC CircuitsMagnetismElectromagnetic InductionWavesOpticsModern PhysicsPhysics GlossaryPractice Tests Are Your Best Friends
 14.1 Voltage 14.2 Current 14.3 Resistance 14.4 Energy, Power, and Heat 14.5 Circuits

 14.6 Capacitors 14.7 Key Formulas 14.8 Practice Questions 14.9 Explanations
DC Circuits
In the previous chapter, we looked at the movement of charges, showing that a net charge creates an electric field with differences in electric potential energy at different points in the field. When two points in a field with a potential difference are connected by a conducting material, electrons will flow spontaneously from one point to another. For instance, when the two terminals of a battery (a source of potential difference) are connected by a copper wire (a conducting material), electrons flow spontaneously from the negative terminal of the battery toward the positive terminal. This mass flow of electrons in a particular direction creates a current, which is the source of the circuits that we will examine in this chapter.
As fans of hard rock know, there are two kinds of circuits, AC and DC. AC stands for alternating current: an electromagnetic generator induces a current that alternates in direction. AC circuits can be quite complicated, so you’ll be relieved to know this is the last you’ll hear of them: they don’t appear on SAT II Physics. However, you should expect a good number of questions on DC, or direct current, circuits. These are the more familiar circuits, where a current flows steadily in a single direction.
 Jump to a New ChapterIntroduction to the SAT IIIntroduction to SAT II PhysicsStrategies for Taking SAT II PhysicsVectorsKinematicsDynamicsWork, Energy, and PowerSpecial Problems in MechanicsLinear MomentumRotational MotionCircular Motion and GravitationThermal PhysicsElectric Forces, Fields, and PotentialDC CircuitsMagnetismElectromagnetic InductionWavesOpticsModern PhysicsPhysics GlossaryPractice Tests Are Your Best Friends
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