Gauss Law for Magnetic fields
o The simplest magnetic structure that
can exist is a magnetic dipole.
o B = B dA = 0 (Integral over any
closed Gaussian surface.)
o All the magnetic field lines that enter
the Gaussian surface must also leave.
o A ma
Assignment Chapter 33
Convert the following E/M waves.
a. 758 nm to frequency
b. 2.52 x 1012 Hz to wavelength
Use E = E0 sin (kx t) and B = B0 sin (kx t) to show that E/x =
What is the intensity of a 60.0 W
Assignment Chapter 30
For a uniform Magnetic Field, what must be the angle between the Area
vector and the field to give of the maximum Magnetic Flux?
A coil of wire has 4 turns. A constant and uniform magnetic field of 2.40 T is
incident on this co
Assignment Chapter 27
A current of 2.50 A flows through a circuit for 8.00 minutes. The current is
supplied by a 12.0 V battery. How much energy is used?
A total resistance of 12.0 is created when two resistors are placed
x = x + (v + v) t
x = x + v t + a t2
v2 = v 2 + 2 a x
( F = m a)
W = mg
Fr = N
Fcp = m v2/r
Work and Energy
A couple of sentences introducing
the lab and the main topic.
Leave blank. (Simply indicate where
it would be.) (Needs to be more thorough on
(Charts and graphs)
IV. Calculations (Need a s
Assignment Chapter 28
A wire carrying 20.0 A has a length of 0.350 m. There is a uniform magnetic field
at 35 degrees to the wire of 0.0250 T. What is the magnetic force on the wire.
A uniform magnetic field points up out of a page for the bottom of
Assignment Chapter 24
A sphere of radius, R, has charge, Q, uniformly distributed throughout its volume.
Find the electric potential difference from points a and b on the same radius from the
center where ra < rb < R.
[Hint: E = (kQ/R)r]
Assignment Chap. 31
A 75.00 resistor, a 95.00 mH inductor, and a 55.00 F capacitor are connected
in series with an ac source with amplitude of 50.00 V.
What is the natural angular frequency?
If the source frequency is 50.00 Hz:
What is the drivin
Assignment Chap 35 & 36
At what angle will 440 nm light produce a third-order maximum when falling
on a grating with 5000 lines per cm.
What is the angular resolution limit set by diffraction for the 100-inch (
Assignment Chapter 22
The electric field at a point in space is 10.0 N/C. What is the force on a charge
of 0.250 C at that point?
Two charges of +0.250 C are placed at the points (1.25 mm, 0) and (-1.25
mm, 0). A third charge
Assignment Chap 21
How many electrons are required to create a charge of -2.00 x 10-14 C?
Find the Force between a charge of + 2.00 C and 2.50 C placed 1.25 m
Find the net force acting on a +2.50 C charge placed at the origin from 3 equal
Assignment Chapter 26
When a switch is closed, the current in a wire is given as i(t) = 1.0A exp(-0.5 t).
How much charge flows out 2.0 s after the switch is closed?
How much charge will flow out if the switch is closed forever?
A wire has 2.0
Assignment Chapter 23
An infinitely long thin rod has positive charge uniformly distributed along it. The
charge per unit length is . Find the electric field a distance r from the rod.
A dipole has two charges of 0.250 C and -0.250 C. What is the fl
Assignment Chap 29
Two long straight wires 10.0 cm apart carry anti-parallel currents of 2.25 A up
and down a page. What is the magnetic field halfway between them?
Two long straight wires carry a current of 0.550 A parallel. If the 1.00 m long
Assignment chap 25
A 12.5 nF capacitor is fully charged by a 12.0 V source.
What is the charge on the capacitor?
What is the energy stored in the capacitor?
The charged capacitor is disconnected from the source and a dielectric, porcelain,
o A capacitor is an electrical device that
The energy stored is electrical
A capacitor can be as simple as 2
conductors (plates) separated by a
When a capacitor is connected to a
LC Oscillations Qualitatively
o Lets examine the effects of an
inductor and a capacitor in series.
o Place a charged capacitor in series
with an inductor and close the
(Draw a picture.)
Charge flows across the inductor
as the capacitor
There are connections between magnetic
and electric fields.
We will learn that moving charges can
create magnetic fields.
Magnetic field from a current in a wire
o Moving charges create magnetic
o A current in a w
o Changing magnetic fields create
o Changing electric fields create
o Here we have a sort of symmetry.
o Together, the electric and magnetic
fields acting together can produce a
o Although we have treated light like a
ray or beam, it also has
characteristics of a wave.
o The characteristics of light we
described easily by using rays can
also be described (more complexly)
using light as a wave.
o Plus, there ar
o Diffraction is more than just the
flaring of light.
o The light also produces an
o This is called the diffraction pattern.
o This pattern can be seen in:
o An Image is a reproduction derived
o Two types
o A virtual image exists only in the
brain, but is said to exist at a virtual
o The object isnt really where the
Consider 2 experiments.
o See fig 30-1 p. 792.
o A loop is connected to a
o A bar magnet is brought close to the
o We see the following:
A current appears only when
there is relative motion between
Now even though the resistor slows down the
electric current, the balls still quickly reach
What we need is a device that will maintain a
constant potential difference.
EMF (Electromotive Force)
(Note: not actually a force)
Consider a positive point charge placed at
Now take another positive test
charge, q0, and place it on the plane. What is the
Force on the test charge?
How does the Force change
as we move the test charge around the pl
The electric field that passes
through a set area is the electric flux.
Scalar but has (+ and -)
= E A
A = Area vector
Direction: normal to the area
o Electric charge like mass is a fundamental
property of nature.
o Unlike mass, charge comes in 2 forms positive
(+) and negative (-).
o Also, where gravity is always attractive; electric
charge can be repulsive or attracti
Electric Potential Energy
Unit: Joule, J
o Electrostatic force is conservative.
o If a charge is placed in a constant E
field, it will experience a Force.
If that charge is moved, work will