Physics 122
Winter 2012
Lab #7
The Energy Gap in a Semiconductor
Introduction
The energy gap in semiconductors can be determined by measuring the resistance as a
function of temperature. In contrast to metals, the resistance of semiconductors
decreases as
Physics 122
Winter 2012
First Hour Exam
Name:_KEY_
Part I. Short answer questions: Circle your single choice of the correct answer. (2 points each
for a total of 20%)
1. If an observer records 1 hour has passed on a stationary clock, she will measure that
Exam 2 Solutions
Part I
1. D
2. C
3. B
4. C
5. B
6. C
7. B
8. C
9. A
10. C
Part II
1. See text
2.
a. 1 2 dx A2 x4 dx A2 / 5 so
b. P
c.
0.75
0.25
1
A 5 and
5x2
2 dx 5x5 / 5 .25 0.236
.75
x x 2 dx 5x6 / 6 0 0.83
1
0
3. a. n = 3; = 1; m = 1, 0, -1; L =
ex
Physics 122
Winter 2012
Lab #1A
The Speed of Light
The speed of light is presently defined to be 299,792,458 m/s (in SI units). As this is an
extremely high speed, physicists have used a wide variety of different indirect measurement
techniques to measure
Physics 122
Winter 2012
Lab#1B
Introduction to Interferometry
In this lab, we will construct and use a Michelson interferometer to measure the
wavelength of light from a helium-neon laser.
Introduction
A beam of light can be modeled as a wave of oscillati
Quiz Solutions
1. (a) First find :
1
1 2 / 3
2
1.342 - Now let T = TFrancis and To = TMaria
So T = To and we want T To = (-1)To = 1 s and we are looking to find T (not To !)
This gives us To = 2.93 s so T = To = 3.93 s
(b) You should all have gotten thi
1
Physics 122
Winter 2012
Electron Spin Resonance
In this experiment you will detect the spin of the electron, and obtain a measure of the
electron's magnetic moment, by measuring the energy of interaction of electrons with an external
magnetic field. In
Physics 122
Winter 2012
Compton Scattering and Coincidence Counting
Introduction
Through the process of coincidence counting this lab investigates the Compton
Effect by measuring the energy of scattered photons. A gamma ray source, 137Cs, emits
high energ
Physics 122
Winter 2012
Lab #2
The Photoelectric Effect
Background
In the nineteenth century, it was observed that light falling on a piece of metal could cause
electrons to be ejected from the surface of the metal. The classical theory of light as an
ele
Physics 122
Winter 2012
Franck-Hertz Experiment
Introduction:
The Franck-Hertz experiment is one of the experiments that showed quantization of energy
levels in atoms. In previous experiments, we have observed that a photon could lose all of its
energy to
Physics 122
Winter 2012
Hydrogen Spectrum
The emission lines of hydrogen was one of the important, well-established, and unexplained sets
of experimental results that Bohr was able to fit with his quantum model of the atom. In this lab,
you will accuratel