Physics Lab Experiments

Cover
Half Title
Title
Copyright
Contents
About the Author
List of Figures
1. The undergraduate laboratories at the University of Oxford.Left: condensed matter laboratory. Right: optics laboratory.
2. The undergraduate laboratories at the University of Bristol
3. Examples of simple low EMF power supplies.Usually the yellow outputs give AC.The black (negative) and red (positive) outputs give DC
4. Left: Low (electric) potential difference connectorswith exposed metal contacts. Right: High (electric)potential difference connectors with shielded metal contacts.The shielding automatically moves back as the plug is connectedinto a socket. Both leads can be piggy-backed to connectmultiple leads to the same place.
5. Examples of high EMF (EHT) power supplies
6. A bracket and belt anchoring a cylinder to the desk
7. A cart used to move gas cylinder. This carthas an extra set of wheels so the user doesn'thave to support part of the weight of the cylinderwhile moving the cylinder
8. A gas regulator. This one is for oxygen only: the knob islabeled and the crossed out symbol of an oil can ispresent in the pressure gauges
9. Left: A gas cylinder key. Right: The spindle on a gas bottle
10. A vacu-vin hand pump
11. A rotary pump
12. A turbomolecular pump backed with a rotary pump.
13. Phase diagram for Nitrogen. Nitrogen is a gas at STP(standard temperature and pressure)
14. A neoprene plastic bucket for storing liquid nitrogen.
15. Liquid Nitrogen Dewars. Left: a 25 liter “onion” Dewarwith a cart Right: a 10 liter Dewar
16. Phase diagram for Carbon Dioxide. Carbon Dioxide isa gas at STP (standard temperature and pressure).
17. Phase diagram for Helium-4. Helium-4 is a gas at STP(standard temperature and pressure)
18. Phase diagram for Oxygen. Oxygen is a gas at STP(standard temperature and pressure)
19. Phase diagram for Argon. Argon is a gas at STP(standard temperature and pressure)
20. Left panel: a lead lined wooden storage box andforceps. Right panel: inside the box and the source insidea metal cup holder
21. A Vernier Scale. The top is the main scale and thebottom in the traveling scale. The left panel shows areading of 0.0 mm; The middle panel shows areading of 0.1mm; The right panel shows a reading of 0.6 mm.
22. A digital calipers measuring; Left: the diameter of a wire andRight: the inside diameter of a pipe
23. A micrometer measuring a: 5.21 mm and b: 3.76 mm.
24. Two different multimeters
25. Simple diagram of a four-wire method of measuring thesample resistance. R1, R2, R3, and R4 are resistanceswhich represent the contact and lead resistances
26. Simple four-wire mounting configuration of a sample tomeasure resistance along in the direction of the current flow
27. Left panel shows a circuit layout of a resistor (typicallyRseries = 1k to 10 k) used as a constant current source.It is connected in series with the sample and the oscillatoroutput on a lock-in amplifier. Right panel shows a circuitdiagram of a (electric) potential difference controlled constantcurrent source. The opamp used is an Linear TechnologyLTC1150CN8#PBF (RS order number 5455629)
28. The front panel of a Stanford Research Systems (SRS)830 lock-in amplifier
29. Left panel shows the circuit setup for a normal 4-wiremeasurement configuration. Right panel shows the circuitsetup when setting the phase. Current is passed though thesample and a series resistor, R. The (electric) potentialdifference drop is measured across only the resistor
30. Inductive cross-talk between wires in two closedcircuits carrying AC signals
31. A signal generator
32. An CRT oscilloscope
33. A digital oscilloscope.
34. A PASCO Science WorkShop 500 Interface boxconnected to a photogate
35. Choosing a sensor in PASCO DataStudio
36. Using PASCO DataStudio to measure the velocity in a photogate
37. Using PASCO DataStudio to produce a distance time graph
38. A Data Harvest QAdvanced Datalogger with aLight Level probe connected to input
39. A screen shot of the Data Harvest EasySense softwareshowing a graph of Light Level against time
40. Illustration of chromatic aberation of a lens. Red light(the dashed line) is refracted less than blue light (the dotted line)
41. Illustration of spherical aberation of a lens
42. Left: Electron diffraction pattern from Gold. Right:A dark field image of islands of Gold
43. Creating a new VI in LabVIEW
44. The LabVIEW program. On the left is the “blockdiagram” window and on the right is the “front panel” window
45. Inserting a “GPIB Read” component in LabVIEW.
46. A LabVIEW program which reads data and produces a graph
47. A LabVIEW program within a “while” loop
48. Photograph of a graticule using a microscope
49. Using ScanIt to set the axis
50. Targets illustrating the differences between the termsaccurate and precise. The center of the target correspondsto the true value. The stars are the individual measurements
51. Graphs illustrating the differences between the termsaccurate and precise. The vertical line corresponds to thetrue value. The vertical axis is a probability distribution(or the number of measurements) and horizontal axis isthe magnitude of the quantity being measured
52. Number lines comparing the spread of data
53. Histogram of the measurements of the current flowingthrough a bulb given in the text
54. Histogram of the measurements of a quantity when thenumber of measurements tends to infinity
55. Plotting an “XY Scatter” graph with Excel 2003
56. Selecting the data series with Excel 2003
57. Adding a polynomial trend line of order 2 to the dataand ensuring the equation is displayed on the chart.
58. Adding X axis error bars. They have a fixed size of ± 0.25.139
59. Plotting a graph with Excel 2010
60. Selecting the data series with Excel 2010
61. Adding axis titles with Excel 2010
62. Adding a linear trend line to the data and ensuring theequation is displayed on the chart
63. Adding X axis error bars. They have a fixed size of ± 1.
64. Switching between editing X and Y error bars
65. Plotting a graph with Kaleidagraph
66. Selecting data for a graph with Kaleidagraph
68. The fit parameters box in Kaleidagraph
67. Adding a Trendline with Kaleidagraph
69. Adding error bars in Kaleidagraph
70. A simple MATLAB graph
71. A MATLAB graph showing two lines and axes labels.
72. A MATLAB graph with vertical error bars
74. The different triangles involved in a two parameter version of theNelder-Mead function minimization algorithm.
73. An Excel trendline, showing the equation of the straightlineand the R2 value are given by Equations 84, 85, and 86
75. A graph showing the maximum and minimum gradientsconsistent with the error bars
76. The Microsoft Excel 2003 Regression Window
77. The Microsoft Excel 2003 Regression package output.
78. Entering the data ranges into Fourier Analysis window.
79. Filling in the FFT Frequency column.
80. Graph of FFT Frequency against FFT Magnitude.
81. Fast Fourier transform of a sine wave with frequency10 Hz. Left panel shows leakage with no windowing functionpresent. Right panel shows leakage reducedwith a windowing function
82. Good and bad scaling of axes
83. Good and bad lines on graphs
84. Always add x and y error bars where possible
85. The Equation Tool Bar in Microsoft Word 2003
86. Inserting an Equation in Microsoft Word 2010
87. The Equation Tool Bar in Microsoft Word 2010
88. Inserting Greek characters in Microsoft Word 2010.
89. Inserting an Equation in Open Office Writer
90. Example poster 1. Based on a final year project
91. Example poster 2. Based on early work towards a PhD.
92. Example presentation slides
93. Moment of inertia of a pendulum
94. Faucault method diagram
95. Reflection from the fixed mirror as the rotatingmirror changes angle
96. Considering the virtual image of the fixed mirror
List of Tables
1. Chemical Hazard Symbols. Usually the border is redand the diagram is black
2. Non-Chemical Hazard Symbols. Usually the text, borderand diagram is black and the background is yellow.
3. Compressed gas cylinder colors
4. Conversion factors for common pressure units
6. Table of temperature and vapor pressures for He-3
5. Table of temperature and vapor pressures for He-4
7. The new laser classifications.
8. The old laser classifications
9. List of common radioactive sources. Protactiniumand Radon are listed with radiation given out by thedecay chain which generates them from Uranium-238and Thorium-232 respectively
10. The SI units
11. The SI prefixes
12. Resistor color codes
13. Thermocouples, Compositions, TemperatureRanges and Sensitivities
14. Effect of changing PID values
15. Relationships for setting PID values
16. Common plugs and sockets
17. Example data for calculation of the mean and variance.
18. Probability that a given measurement is within “z”standard deviations of the mean.
20. Example calculations for a regression line
19. Example data for a regression line
21. Example data for Nelder-Mead method
22. Commonly used LaTeX symbols
23. Papers Sizes
Chapter 1 Introduction
1.1 Characteristics of the Laboratory
1.2 Demonstrating Undergraduate Physics Laboratory
Chapter 2 Safety
2.1 Hazard Symbols
2.2 Electrical
2.3 High Voltages
2.4 Gas Cylinders
2.5 Vacuum Pumps
2.5.1 Pressure Units
2.5.2 Hand Pumps and Vacu-vins
2.5.3 Diaphragm Pump
2.5.4 Rotary Pump
2.5.5 Diffusion Pump
2.5.6 Turbomolecular Pump
2.6 Cryogenics
2.6.1 Liquid Nitrogen
2.6.2 Dry Ice
2.6.3 Liquid Helium
2.6.4 Helium-3
2.6.5 Liquid Oxygen
2.6.6 Argon
2.6.7 Cryogen Free Cooling
2.7 Lasers
2.8 Ionizing Radiation
Chapter 3 Making Measurements
3.1 SI Units
3.2 SI Prefixes
3.3 Vernier Calipers
3.4 Digital Calipers
3.5 Micrometer
3.6 Balances
3.7 Ammeters
3.8 Voltmeters
3.9 Resistor Color Codes
3.10 Multimeters
3.11 Further Ideas on Measurement of Resistance
3.12 Constant Current Sources
3.13 Lock-in Amplifers
3.14 Further Ideas on Reducing Noise in Electrical Measurements
3.15 Signal Generator
3.15.1 TTL
3.16 Oscilloscopes
3.17 Light Gates
3.17.1 Velocity with One Light Gate
3.17.2 Velocity with Two Light Gates
3.17.3 Acceleration with Two Light Gates
3.17.4 Acceleration with One Light Gate
3.18 PASCO Science Workshop Interface
3.19 Data Harvest
3.20 Pressure Gauges
3.21 Temperature Measurement
3.21.1 Near Room Temperature
3.21.2 Low Temperatures
3.21.3 High Temperatures
3.22 PID and Temperature Control
3.23 Kaye and Laby Tables
3.24 Microscopes
3.24.1 Optical Microscopes
3.24.2 Transmission Electron Microscope
3.24.3 Other Microscopes
3.25 Spectroscopes
3.26 Computers
3.26.1 Plugs, Sockets, and Connectors
3.26.2 Computer Data Logging
3.26.3 Still Cameras and Scanners
3.27 Video Cameras
3.28 Other Researcher's Data
3.29 Wii Controllers
3.30 Traditional Photographs
Chapter 4 Data Analysis and Errors
4.1 Accuracy and Precision
4.2 Measurement Errors
4.2.1 Random Error
4.2.2 Systematic Error
4.2.3 Zero Error
4.3 Uncertainty
4.4 Resolution
4.5 Tolerance
4.6 Sensitivity
4.7 Response Time
4.8 The Mean of the Sample
4.9 Variance and Standard Deviation of the Sample
4.10 Measurement Distributions
4.11 Standard Error on a Single Measurement
4.12 Standard Error on the Mean
4.13 Estimation of Errors
4.14 Gaussian Error Distribution
4.15 Combination or Propagation of Errors
4.15.1 Linear
4.15.2 Products and Quotients
4.15.3 General Functions
4.15.4 Appropriate Significant Figures in FinalAnswers and Errors
4.16 Plotting Appropriate Graphs
4.16.1 Drawing Lines of Best Fit and Finding Gradients
4.16.2 Error Bars on Graphs
4.16.3 Straight Line Graphs
4.16.4 Log Graphs
4.17 Graph Drawing Software
4.17.1 Excel 2003 and Prior Versions
4.17.2 Excel 2010
4.17.3 Kaleidagraph
4.17.4 MATLAB
4.18 Least Squares Fitting
4.18.1 Regression line of y on x
4.18.2 Steepest Descent
4.18.3 Gauss-Newton
4.18.4 Levenberg-Marquardt Method
4.18.5 Nelder-Mead Method
4.18.6 Distribution Testing
4.19 Uncertainty in Gradients and Intercepts of Graphs
4.20 Fourier Transform
4.20.1 Window Functions
Chapter 5 Presenting Results
5.1 Lab Book
5.2 Reports
5.2.1 Software
5.2.2 Structure
5.2.3 Graphs, Tables, and Diagrams
5.2.4 Referencing
5.2.5 Equations
5.2.6 Special Characters
5.3 Posters
5.3.1 Software
5.3.2 Paper Sizes
5.4 Presentations
5.4.1 Software
Chapter 6 Common Experiments
6.1 Example Experiments
6.1.1 Measuring Acceleration due to Gravity
6.1.2 Measuring the Speed of Light
6.2 Example Reports
6.2.1 Example Report: Charge Mass Ratio of an Electron
6.2.2 Example Report: Investigating Radioactivity
6.2.3 Example Report: Latent Heat of Vaporizationof Liquid Nitrogen
Index