Download Lecture 10.2: Identifying Equivalent Resistor Circuits - Prof. Xiangjun Xing and more Study notes Physics in PDF only on Docsity! Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Lecture 10.2 Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Which of these diagrams represent the same circuit? A. a and b B. b and c C. a and c D. a, b, and d E. a, b, and c Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. EXAMPLE 32.10 A combination of resistors
A te
Rank in order, WY 7 >
from brightest to = +] a4 c
dimmest, the ‘> B
identical bulbs A D
to D. K
T= 7,402
AC= D> BSA ToT, ad Fy,
“BASC=D>B—
GA=B=C=D)_ - xR
\/ D.A>B>C=D
EASES BSD _ . u
-p- - Pe — Vs P= Ve _ Vet
R 1S RT Re
Vp = Ve + Vp
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. 7 Ve > Ke Ve
Rok =Pp
How should Ammeters be Connected
* Ammeter measures the current flow through it.
« Ammeter must be connected in series with circuit elements
whose current needs to be measured!
* Ammeter also has resistance (very smail).
W
~ |
GT ob I,
|
i
2D iI] ah -&
Ra
ren
, atin
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Problem-Solving Strategy: Resistor circuits 1. Assign current to each branch 2. Use Kirchhoff’s Junction law to find relation between currents 3. Using Kirchhoff’s loop law and Ohm’s Law to set up one equations for each loop 4. Solve these equations Example: two loop circuit, Find the current through and
voltage across the 100Ohm resistor
L
\ Suneto, Law! :
2
Looe F,4r.
Loof 2 S 200 0
¥
+IAv + @Be0nxT) + (400 x2,)
—- Rv= O
Loop 2 -
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. /
J,
@)
Zoon xty + Wo xt, =4V
200oLX¥ TL — Boo f yt, = 12V —— G)
Ox3 + @:
(Qeor tron )XT = BIV+ av) =sev
33V
yo = 222 = 0,03
foo O08 A 71 = —o0t4
tie t- T= OeB A (osrp) = 0 064
Cimet 4 Ve Wage
goo] 9.03 A Cup) Vv
toro oot A (AF ) 2V
RC Cyowks: Dis chav quar Capacitor octe
Loop law at t—3o-;
*)
FiGure 32.38 An RC circuit. AVE I)-R= 0
{a) Before the switch closes AVect) = Qo # T(t) od ic
The switth wiles, c ; ce
close at f= 0. ‘, 1
we ~ a
Mer ed@ =o
eb pee R
oe 0S 4y,- 10H). ~ Re Gre).
th
- a 'C -s
Charge Q, QM ~ Qe ° c= RC
AV. = JIC
Qe= Qee=d
(b) After the switch closes
se 2 = atk. @ 5%
R
Avy,=—e = OI ret}
Charge Q The current is reducing the
AV, = GIC charge on the capacitur.
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. t
