Hydrogen Fuel Cells
Meredith Thomas
Elect. 101
December 4, 2008
Hydrogen Fuel Cells
Hydrogen fuel cells have the potential to solve many major problems America faces
today. Hydrogen is a versatile energy carrier that can be used to power nearly every end-
U niform Circular Motion
James Poole
* * *-* *-9001
Physics 211 L Monday 12:20 P.M.
Project due Monday March 23, 2009.
Abstract: I n this lab I used the relationship between force and acceleration
i n uniform circular motion to determine the mass of an ob
Physics 212
LCR Oscillations
10/30/2009
Fall 2009
Electronic Signal Speed
In an AC circuit, electrons are moving back and forth at a frequency . The signal that the
electrons receive to change direction comes from the generating station. What is the speed
Physics 212
10/26/2009
AC Generation
Fall 2009
Schedule
AC Power
Impedance, Phasors
Oscillations
Magnetism
Maxwells Equations
This Week
Next Week
Summary
Electromagnetic Storage Devices
Inductor
Capacitor
NB
L=
i
B2
uB =
20
1
U B = Li 2
2
C=
q
V
1
U
1797-1878
Physics 212
Fall 2009
Induction III
Inductors
10/23/09
Summary
Faradays Law: A changing magnetic ux causes an EMF.
dB
= N
dt
Lenzs Law: An induced current has a direction such that the magnetic eld
due to the current opposes the change in the m
Physics 212
Electromagnetic Induction II
10/21/09
Fall 2009
Faradays Law
An ammeter is connected to a coil of wire. A magnet is sitting motionless next to the wire
such that its south end is near the coil and perpendicular to the plane of the coil as show
Physics 212
Electromagnetic Induction
10/19/09
Fall 2009
Summary
Solenoid - Turns of current carrying wire in close-packed coils
current enclosed
n =# turns / length
ienc = ni
Amperes Law
B ds = oienc
closed
loop
Bh = o nih B = o ni
Induction
Magnet Stea
PHYS 212
Fall 2009
Fields Due to Currents
10/5/09
Summary
Force on a wire
F = qE + qv B
F = iL B
Torque on a current loop
= B = NiA
Force on a charge
p
Electric Dipole
Magnetic Dipole
Q - Is a current loop a dipole magnet?
Torque Example
A coil of wire
Phys 212
Amperes Law
Fall 2009
10/7/09
Schedule
Wednesday - HW6 Due
Thurs, Fri - Fall Break
Mon - Review I
Wed - Review II (HW 7 Due!)
Fri - Exam II
Exam is on all subjects covered to date
Emphasis on material since last test
Lecture questions, HW4-7
PHYS
Fall 2009
Review II
10/14/09
Schedule
Wednesday
Magnetic Concepts, HW problems
Review of Earlier Material
Friday - Exam2!
Same procedure as Exam1
Magnetic Force on a Wire
A portion of a loop of wire passes between the poles of a magnet as shown.
Electric Charge
Electricity and Magnetism
! Electricity and magnetism have been known for
thousands of years
The ancient Greeks knew that a piece of amber rubbed
with fur would attract small, light objects
The word for electron and electricity derived f
Electric Fields
The Electric Field (1)
So far we have thought of the electric Force
between two stationary charges
Suppose one charge were moving, how would the
second charge know that the first charge has
moved?
What if there were other charges, how w
Gauss Law
Water Flux
Let s imagine that we put a ring
with area A perpendicular to a
stream of water flowing with
velocity v
The product of area times
velocity, Av, gives the volume
of water passing through the
ring per unit time
The units are m3/s
If
1
PHYS 212 Essentials of Physics II: Fall 2015
About the Lectures and the Professor
Lectures: We shall begin promptly at the appointed hour. The rst 10-15 minutes of each
lecture will be devoted to a brief recapitulation of previous results and to discuss
Physics 212
LCR Circuits
10/28/2009
Fall 2009
Summary
AC Voltage
RMS (Root-Mean-Square) VRMS, IRMS
V = V0 sin(t )
= 2f
f=
1
T
=
IRMS =
2
T
IPVP = ISVS
Magnetic ux change is the same
due to iron core
N
VS = S V p
NP
IS = IP
NS>NP - step up; NS<NP - step
Physics 212
Fall 2009
Magnetism II
11/04/09
Maxwells Equations
Which one of the following is not one of Maxwells fundamental equations of electromagnetism?
a) Gauss law for electricity
b) Coulombs law
c) Faradays law
d) Ampere-Maxwell law
e) Gauss law for
Diffraction Measurements
Allison Beech, Dae Bigach, Alex Galan
April 18, 2016
Abstract: In this experiment, a helium neon laser was used to measure and compare diffraction
patterns produced by a CD, DVD and human hair. The diffraction pattern created by t
PHYS
Fall 2009
Review I
10/12/09
Schedule
Monday
Magnetic Concepts, HW problems
Wednesday
Magnetic Concepts, HW problems
Review of Earlier Material
Field and Force
A positive charge moves parallel to a wire.
If a current is suddenly turned on, which
PHYS
FALL 2009
Magnetic Fields
Magnetic Forces
9/30/09
Summary
When both electric and magnetic elds are present, a moving charge will feel a combined force.
!
!
!
F = qE + qv " B
This is known as the Lorentz Force
!
!
F = qE
!
!
!
!
F = qv " B
Magnetic Fo
PHYS
FALL 2009
Magnetic Fields
Magnetic Forces
10/02/09
Schedule
Today - Magnetic Fields III
Monday - Magnetic Fields due to currents
Wednesday - HW6 Due
Thurs, Fri - Fall Break
Mon - Review I
Wed - Review II (HW 7 Due!)
Fri - Exam II
Next Week
Mag
Phys212 Fall 2009
Circuits II - 9/25/09
Solving Circuits
Potential Method - Rules Current Direction - current ows in the direction that positive charge carriers move
Kirchhoffs Junction Rule - sum of currents into a junction equals the sums of the
current
PHYS 212
FALL 2009
Magnetic Fields
Magnetic Forces
9/28/09
Magnetic Forces
It is observed that objects attract or repel each other or attract bits of iron
Like poles repel
Opposite poles attract
Dipoles can be in
oriented in many
different directions
Magn
PHYSICS 212
Fall 2009
Current and Resistance
9/21/2009
Moving Charges
Switch from electrostatics to charges in motion
Moving Charges Cause Currents
household wiring
lightening
solar wind
beam of electrons
nerve-currents in our body
Different Types of Mate
Physics 212 Fall 2009
Circuits - 9/23/09
Current and Resistance
b
Current
i=
q
t
(A)mpere=(C)oulomb/(s)econd
Resistance
R
vd =
i1
A ne
V=Vb-Va
a
V
i
Ohm=Volt/Amp
R=
L
A
Power
i
Ohmic Devices:
U
= P = iV
t
P = IV
CJ J
AV =
= = (W ) att
sC s
V = IR
V 2
V2
Physics 212 - Fall 2009
RAM
Capacitor Charged = 1
Capacitor Uncharged = 0
Capacitance II
9/18/2009
Recap Capacitance
q = CV
The amount of charge stored (q) depends on
C - Capacitance - units: Farads=Coulomb/Volt
V - potential difference across the plates
Physics 212 - Fall 2009
Capacitance I
9/14/2009
Schedule
Today - Capacitors I
Tuesday - New homework available
Wednesday - CAPA hour, Exam
Friday - Capacitors II
What is a Capacitor?
Useful Device - Stores charge
Can be any shape, big or small
Parallel pl
Haydon Strable and Thalia Hobson
Phys 212L Section 005
Diffraction
Wednesday 1:10-3:10
Due: Wednesday March 15, 2017
Introduction/Background
Light travels as electromagnetic waves that have the ability, when obstructed, to exhibit
interference as well as
Haydon Strable and Thalia Hobson
The Balmer Series
Physics 212L: Section 005
Wednesday 1:10-3:10
Due: March 22, 2017
Abstract
Introduction/Background
The Balmer series was discovered by Johann Balmer in 1885. It is a series of visible,
spectral emission l
mass
m1 (2.4e-6 kg)
m2 (4.2e-6 kg)
m3 (6e-6 kg)
m4 (9.5e-6 kg)
mass
m1 (2.4e-6 kg)
m2 (4.2e-6 kg)
m3 (6e-6 kg)
m4 (9.5e-6 kg)
Mass (kg)
m1 (2.4e-6 kg)
If (Amps)
IR (Amps)
Avg (IF)
2.032
1.838
-2.564
2.32
-2.38
1.939
-2.38
3.05
-3.105
3
-2.867
3.13
-3.214