1 / 41

Lecture 11 Electromagnetic Oscillations and Alternating Current Ch. 31

Lecture 11 Electromagnetic Oscillations and Alternating Current Ch. 31. Topics Generators Transformers LC Circuit Qualitatively Electrical and Magnetic energy oscillations Alternating current Pure C and L circuits Series RLC circuit Power and Transformers Demos Elmo Polling.

roxy
Download Presentation

Lecture 11 Electromagnetic Oscillations and Alternating Current Ch. 31

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Lecture 11 Electromagnetic Oscillations and Alternating Current Ch. 31 • Topics • Generators • Transformers • LC Circuit Qualitatively • Electrical and Magnetic energy oscillations • Alternating current • Pure C and L circuits • Series RLC circuit • Power and Transformers • Demos • Elmo • Polling

  2. What is a Generator? Coil of wire  B Where w is the rotational angular frequency of the generator w= 2pf and f= 60 Hz

  3. Driven RLC Series Circuit

  4. Series RLC • Show Generator voltage vs time on scope. • Vary frequency • Show voltage across resistor compared to signal voltage • How is signal voltage related to voltage across resistor • Vary frequency - ELI the ICE man • Show voltage across inductor compared to resistor. • Voltage across resistor is in phase with current through resistor • Does voltage across inductor lead or lag the current • Show voltage across capacitor compared to resistor. • Voltage across resistor is in phase with current through resistor • Does voltage across the capacitor lead or lag the current • Show phase angle is related to impedance in circuit and is • frequency dependent • Show resonance by varying frequency. • Need table of numbers for some frequency and at resonance.

  5. Series LCR circuit

  6. V=10 Volts

  7. Peak value Effective Power rms=root-mean-square

  8. Low Pass Filter High Pass Filter

  9. Chapter 13 Problem 17 In an oscillating LC circuit, L = 28.0 mH and C = 7.50 µF. At time t = 0 the current is 9.50 mA, the charge on the capacitor is 3.20 µC, and the capacitor is charging. (a) What is the total energy in the circuit? (b) What is the maximum charge on the capacitor? (c) What is the maximum current? (d) If the charge on the capacitor is given by q = Q cos(ωt + ϕ), what is the phase angle ϕ? (e) Suppose the data are the same, except that the capacitor is discharging at t = 0. What then is ϕ?

  10. Chapter 31 Problem 21 In an oscillating LC circuit with C = 62.0 µF, the current as a function of time is given by I = (1.10) sin(2500t + 0.670), where t is in seconds, I in amperes, and the phase angle in radians. (a) How soon after t = 0 will the current reach its maximum value? (b) What is the inductance L? (c) What is the total energy?

More Related