{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

# Lect11 - Physics 212 Lecture 11 Today's Concept RC...

This preview shows pages 1–8. Sign up to view the full content.

Physics 212 Lecture 11, Slide 1 Physics 212 Lecture 11 Today's Concept: RC Circuits (Circuits with resistors & capacitors & batteries)

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

View Full Document
Music Who is the Artist? A) Miles Davis B) Wynton Marsalis C) Chris Botti D) Nina Simone E) Chet Baker Ultimate West Coast Cool Jazz from the 50’s Definitive version of My Funny Valentine Hypnotizing voice… DVD Must-See: Twilight of his career/life Interviewed by Elvis Costello (Diana Krall’s husband) Van Morrison does “Send in the Clowns” Physics 212 Lecture 11
Physics 212 Lecture 11, Slide 3 Your Comments 05 “WHERE ARE THE GRADES??? Lazy TA's in my opinion. In phys 211 we got our grades the next day. ..” “The relationship between time and resistor over a short time and over a long time.” “I do not understand why it changes over a long time.” “the last question on two loop RC circuit” We’ll emphasize the limiting cases I don't think this was too bad. It sucks that we will have to memorize the equations for q(t) and I(t) though Remember that I = dq/dt You need to know the solution to one differential equation (exponential) “My friends and I discussed and we are not sure if we RCing the concepts right. We may just have to throw in the Tau-el.”

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

View Full Document
Physics 212 Lecture 11, Slide 4 Today’s Plan: 1) Examples with switches closing and opening - What changes? - What is constant? 2) Example problem 3) Exponentials Key Concepts: 1) Understanding the behavior of capacitors in circuits with resistors 2) Understanding the RC time constant 07
The 212 Differential Equations • We describe the world (electrical circuits, problems in heat transfer, control systems, etc., etc.) using differential equations • You only need to know the solutions of two basic differential equations Physics 212 Lecture 11, Slide 5 / 0 1 0 t dq q q q e dt τ - + = = ( ) 2 2 0 2 0 sin d q q q q t dt ω φ + = = +

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

View Full Document
Physics 212 Lecture 11, Slide 6 RC Circuit (Charging) • Kirchoff’s Voltage Rule • Short Term (q = q 0 = 0) • Long Term (I c =0) R V battery C a b battery q -V + +IR = 0 C - + + = 0 0 0 battery V I R battery 0 V = R - + + = 0 0 battery q V R C = battery q CV Intermediate - + + = 0 battery q dq V R C dt - = - / ( ) (1 ) t RC q t q e - = / 0 ( ) t RC I t I e 11 a R V battery C b • Capacitor uncharged, Switch is moved to position “a”
Physics 212 Lecture 11, Slide 7 13 Checkpoint 1a Checkpoint 1b Close S1, V 1 = voltage across C immediately after V 2 = voltage across C a long time after A) V 1 = V V 2 = V B) V 1 = 0 V 2 = V C) V 1 = 0 V 2 = 0 D) V 1 = V V 2 = 0 A circuit is wired up as shown below. The capacitor is initially uncharged and switches S1 and S2 are initially open. “There is no voltage at the get go.” “There is no current, so the resistor has no voltage drop” “As time progress, the voltage will drop to 0 since the current goes to 0” “The capacitor is completely charged and doesn't allow any current to flow so no voltage can drop across the resistor. All voltage must drop across the capacitor” Checkpoint 1a

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

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 30

Lect11 - Physics 212 Lecture 11 Today's Concept RC...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online