Editing and Proofreading
One lesson I learned to late
One lesson I learned too late was hiding peoples items. I used to hide peoples items for fun to witness
their reaction. One time, that went over t
The Electric Dipole
Find the electric field at P
E
ke q
x a
,
i
2
E
ke q
x a
2
i
1
1
k q
E E E
i
i e
i
2
2
2
2
x a x a
x a x a
x 2 2ax a 2 x 2 2ax a 2
x a 2 x a 2
k q
ke q
i e
i
2
Maxwells Electrodynamics
Electromagnetism as Maxwell found it
E dA q
enclosed
/ 0
S
B dA 0
S
d
E ds d t B d A
C
S
B ds J d A
0
C
S
Magnetic field on the perpendicular bisector of a thin straight
w
Some important results from
chapter 24
Suppose we are handed a spherical but not necessarily
uniform distribution of electric charge on an insulating
ball. Is there a way to figure out what the distri
RC Circuits
Initially uncharged capacitor. Throw switch to a.
Capacitor begins to charge. Positive charge accumulates
on the upper plate, negative charge on the lower plate.
Capacitor begins to charge
More on Electric Charge
charge polarization of conductors
charge polarization of insulators
The atoms of most materials have a
regular arrangement.
Quantization of electric charge
Quantization of elec
Magnetic Forces and Torques on
Currents
What will be the direction of the force on the wire if
current flows up the page?
Let a current flow in a wire and consider a small piece of wire
of length ds.
Induced Electric Fields
Whenever the surface enclosed by a conducting loop experiences a
changing magnetic flux, there is always an emf around the loop associated
with this changing flux.
B B dA
S
E
Inductance
An inductor is an arrangement of wires or other conductors used to
produce a magnetic field.
Circuit theory symbol:
Consider an inductor composed of N turns of wire.
When a current I flows
Induction motor
Direction of torque on rotating magnet?
Conservation of angular momentum
A
C
Four solenoids, shown at
time t 0, driven by
ac currents at the same
frequency but with 90
phase difference
The Flux Concept
Total current through the disk
J dA
disk
Total current through the hemisphere
hemisphere
J dA
For a closed surface, the convention is to choose
the areal vector outwards, away from
The Electric Field
9 10 Nm
9
F3
33.75 N
i
2
2 10 C 3 10 C
i
4 10 m
/C
6
2
2
2
6
F6 2F3 67.5 N
i
F1 1 F3 11.25 N 11.25 N
i
i
3
In all these cases, the force on a point charge
is proportional
Good Idea Gone Bad
It was a warm summer Mediterranean evening on the island of Mykonos. My Parents and I had hired
two chefs and a waiter to make a dinner for us and our friends. We had done this for
The Good and Bad about scuba diving
Scuba Diving is a world Renown Activity too do. It requires both patience, practice and skill in order to
dive. There are many risks involved with doing this activi
The Good and Bad about scuba diving Revised
Scuba Diving is a world Renown Activity too do. It requires both patience, practice and skill in order to
dive. There are many risks involved with doing thi
The Good and Bad about scuba diving
Scuba Diving is a world Renoun Activity too do. It Requires both pacience, practice and skill in order to
dive. There are also many risks involved with doing this a
Describe the prewriting strategy that you used for this lesson and explain how well it
worked.
For This lesson we used the Lists of Lists way of gathering ideas in order to come up with a brain storm.
Applications of Capacitors
V E
q C V
0 A V
d
V E
q C V
0 A V
d
Suppose d is decreased. Then q is increased:
there will be a flow of charge through the circuit.
This flow of charge is an electric c
Think of the electric current as due to the motion of small
particles, called charge carriers. The average particle has
charge q and the particles are distributed uniformly
throughout the conducting v
Sources of the Magnetic Field
A magnetic north pole, placed in an external
magnetic field, is attracted in the direction of
that field.
A magnetic south pole, placed in an external
magnetic field, is
The Hall Effect
Can we use magnetic fields to tell us what is the
sign of the charge carriers in ordinary conductors?
Suppose the charge carriers are positively charged
FB q v B
Suppose the charge car
Inductance problems
The switch in the above circuit is closed and kept closed for a long time. Eventually,
the emf across the inductors becomes zero. The switch is then opened
A. After the switch is o
General DC Circuits
series connections of resistors: Req R j
j
parallel connections of resistors: 1/Req 1/ R j
j
Simplifying a simple circuit
I bat
3V
0.169A
17.769
In particular, the current throug
Charged conducting spheres
Consider two neutral metal spheres, one
of them of large radius R1 and the other
of smaller radius R2 and imagine that
they are separated by a distance that is
much greater
Computing Induced Currents
Whenever the surface enclosed by a conducting loop experiences a
changing magnetic flux, there is always an emf around the loop associated
with this changing flux.
B B dA
S
Dielectrics
Electrical properties of insulators
The atoms of most materials have
a regular arrangement.
When an electric field is imposed
on the dielectric, the atoms
polarize
The polarization tends t
Chapter 29 problems
The three figures above show currents in uniform magnetic fields.
All currents are the same, their lengths are the same and all
magnetic fields have the same magnitude.
Which curre
Combinations of Capacitors
q1 q2 0
q1 q2
q2 q3 0
q2 q3
When capacitors are connected in series,
the charge is the same on all the capacitors
q1 q2 q3
How much charge passed through the battery?
A. q
B
Applications of Amperes Law
Current flows uniformly over a wire of radius R carrying a total
current I. Find the magnetic field everywhere, inside and
outside the wire.
First part of problem: r < R
Wh