1) If a 4-F capacitor and an 8-F capacitor are connected in parallel, which has the larger potential difference across it? Which has the larger charge?

Quiz

2)

Two capacitors are connected in series as shown. If they were initially uncharged, what will be the charge inside the dotted box after connecting points A and B to a battery of voltage V?

A B

3) If the wire connecting the capacitors is bent so that capacitors look like

A

B

how do you now call the arrangement?

a

b

C1C3

C5C4

C2

C1=C5=8.4 F and C2=C3=C4=4.2 F The applied potential is Vab=220 V. a)What is the equivalent capacitance of the network

between points a and b? b) Calculate the charge on each capacitor and the

potential difference across each capacitor.

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E

0 rdE

0 rdE

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2E

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C

B

A

A

B C

D

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Electric field near the surface of a conductor

0

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A

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Q

V

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0

Capacitors in series: ...1111

321

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Capacitors in parallel: ...321 CCCCtot

22

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Insulating sphere with charge Q uniformly spread throughout the volume

A

E

r

204

1

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304

A

Conducting sphere with charge Q

A

E

r

204

1

r

QEAr

0 EAr

V

r

A

A

Q

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1

r

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04

1

A

QVAr

04

1

Current, Ohm’s Law, Etc.

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A

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t

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,Ri

V where R is resistance

Resistance does not vary with the applied voltage

resistor

Ampere

VoltsR

Experimentally it is found that R depends on the material the wire is made of and its dimensions. Does not depend on the shape.

A

lR

areatheisAlengthisl ,

yresistivitis

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