Review21 - Modified from College Physics, 7th Ed., Serway,...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Modified from College Physics , 7 th Ed., Serway, Faughn, and Vuille. For the quizzes and tests, you should know all the concepts and equations in this summary. Section 21.1: Resistors in an AC Circuit If an AC circuit consists of a generator and a resistor, the current in the circuit is in phase with the voltage, which means the current and voltage reach their maximum values at the same time. In discussions of voltages and currents in AC circuits, rms values of voltages are usually used. The rms values of currents and voltage ( I rms and V rms ), are related to the maximum values of these quantities ( I max and V max ) as follows: 2 , 2 max max V V I I rms rms = = [21.2] [21.3] The rms voltage across a resistor is related to the rms current in the resistor by Ohm's law : R I V rms rms = [21.4] Section 21.2: Capacitors in an AC Circuit If an AC circuit consists of a generator and a capacitor, the voltage lags behind the current by 90°. This means that the voltage reaches its maximum value one-quarter of a period after the current reaches its maximum value. (Positive voltage opposes current flow, as in a resistor.)
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 3

Review21 - Modified from College Physics, 7th Ed., Serway,...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online