# Lect21 - Physics 212 Lecture 21 Physics 212 Lecture 21...

This preview shows pages 1–7. Sign up to view the full content.

Physics 212 Lecture 21, Slide 1 Physics 212 Lecture 21

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

View Full Document
Music Who is the Artist? B) War C) Tower of Power D) Average White Band E) Chicago Why? Topic for today = Power Why not Tower of Power ??? Memories from Bay Area ……
Physics 212 Lecture 21, Slide 3 Your Comments 05 We’ll do our best to restate the Big Ideas and give examples There was an overwhelming amount of formulas for the average power in RLC circuits. It would be nice if you gave us some methods to remember all of them.” quality factor, what is the motivation behind it to study?and please checkpoints, as i m confused But of course! “I learned in differential equations that if there is resonance is a system, the system is then destroyed, such as bridges and buildings. Does the same things happen in circuits? ” Depends on the quality factor, e.g. V L,max =Q ε max the transformers were a tad bit confusing” Short review + demo ABSOLUTELY We will review today. . Wow this is still really hard - can you go over in great detail how to describe and work with rlc ckts using phasors and phase vectors?”

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

View Full Document
Physics 212 Lecture 21, Slide 4 What Did We Learn in Office Hours Yesterday? I max X L I max X C I max R L R C ε max PHASORS ARE THE KEY !! FORMULAS ARE NOT ! START WITH PHASOR DIAGRAM DEVELOP FORMULAS FROM THE DIAGRAM !! I max R ε max = I max Z I max (X L -X C ) I max X L I max X C I max R V = Projection along Vertical ω X L = ω L X C = 1/ ω C R φ X L -X C
Physics 212 Lecture 21, Slide 5 Peak AC Problems • “Ohms” Law for each element – NOTE: Good for PEAK values only) – V gen = I max Z – V Resistor = I max R – V inductor = I max X L – V Capacitor = I max X C • Typical Problem A generator with peak voltage 15 volts and angular frequency 25 rad/sec is connected in series with an 8 Henry inductor, a 0.4 mF capacitor and a 50 ohm resistor. What is the peak current through the circuit? L X L ω = ( ) 2 2 L C Z R X X = + - 1 C X C = 07 L R C 200 X L = = Ω 1 100 C X C = = Ω ( ) 2 2 112 L C Z R X X = + - = Ω A Z V I gen 13 . 0 max = = X L X C R

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

View Full Document
Lecture 21, Slide 6 Peak AC Problems • “Ohms” Law for each element – V gen = I Z – V Resistor = I R – V inductor = I X L – V Capacitor = I X C • Typical Problem A generator with peak voltage 15 volts and angular frequency 25 rad/sec is connected in series with an 8 Henry inductor, a 0.004 Farad capacitor and a 50 ohm resistor. What is the peak current through the circuit? Which element has the largest peak voltage across it? A) Generator E) All the same. B) Inductor C) Resistor D) Capacitor = max max V I X 12 L R C L X L ω = ( ) 2 2 L C Z R X X = + - 1 C X C = 200 L X L = = Ω 1 100 C X C = = Ω ( ) 2 2 112 L C Z R X X = + - = Ω A Z V I gen 13 X C R
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 27

Lect21 - Physics 212 Lecture 21 Physics 212 Lecture 21...

This preview shows document pages 1 - 7. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online