273' Electromotive Force emf

1
27-3. Electromotive Force (emf)
Charge Pump
2
27-3. Electromotive Force (emf)
3
27-4. Current in a Single Loop
4
27-5. Internal Resistance
5
27-6. How to Solve??
6
27-6. How to Solve??
7
(No Transcript)
8
27-6. Potential Difference (R in Series)
Behave like capacitors in parallel!
9
27-7. Multi-Loop Circuits (R in Parallel)
Junction a
Loop 1
Loop 2
Same as capacitors in series.
10
27-7. Multi-Loop Circuits (R in Parallel)

• Which circuit has the largest equivalent
  resistance?
• Assuming that all resistors are the same, which
  one dissipates more power?
• Which resistor has the smallest potential
  difference across it?

11
(No Transcript)
12
27-7. Multi-Loop Circuits
Find the equivalent resistance between points F
and H
R 10W
(Hint For each pair of points, imagine that a
battery is connected across the pair.)
13
27-7. Multi-Loop Circuits
Find the equivalent resistance between points F
and G
14
27-7. Multi-Loop Circuits
Given Es and Rs
Find the currents
Start with
15
(No Transcript)
16
27-7. Monster Mazes
If all resistors have a resistance of 4W, and all
batteries are ideal and have an emf of 4V, what
is the current through R?
17
27-7. Monster Mazes
If all resistors have a resistance of 4W, and all
batteries are ideal and have an emf of 4V, what
is the current through R?
18
27-7. Monster Mazes
If all capacitors have a capacitance of 6mF, and
all batteries are ideal and have an emf of 10V,
what is the charge on capacitor C?
19
(No Transcript)
20
27-9. RC Circuits
21
27-9. RC Circuits
22
27-9. RC Circuits
Charging
23
27-9. RC Circuits
Charging
Which witch is which??
24
27-9. RC Circuits

• E 1 kV, C 10 µF, R1 R2 R3 1 MW.
• With C completely uncharged, switch S is suddenly
  closed (at t 0).

• Whats the current through each resistor at t0?
• Whats the current through each resistor after a
  long time?
• How long is a long time?

25
27-9. RC Circuits
The three circuits below are connected to the
same ideal battery with emf E. All resistors have
resistance R, and all capacitors have capacitance
C.

• Which capacitor takes the longest in getting
  charged?
• Which capacitor ends up with the largest charge?
• Whats the final current delivered by each
  battery?

26
27-9. RC Circuits