College of Liberal Arts & Sciences
5H25.10 - Coil & Compass, Rods, Gaussmeter, & Tangent Galvanometer
Hook the power supply to the coil and turn on the power. The magnetic field outside and inside the coil can be mapped with the Gaussmeter and probes. The axial probe will work better inside the coil. Another way to demonstrate this is to set the coil on its side and hang two of the rods in the center of the coil. With no power the rods will touch in the center of the coil. Turn up the voltage and the rods will separate a distance that is proportional to the voltage. Turn off the power and observe that the rods still retain some residual magnetism.
The tangent galvanometer is an antique instrument used to explore the magnetic field of the Earth. A dip needle should also be used when doing this experiment/demonstration.
- James Lincoln, "Biot-Savart Law with a Smartphone: Phyphox App", TPT, Vol. 62, #1, Jan. 2024, p. 72.
- John E. Proctor, Harvey Thomas Gould, "Derivation of the Field Due to a Magnetic Dipole Without Use of the Vector Potential", TPT, Vol. 61, #1, Jan. 2023, p. 40.
- Hyejin Ha, Taehun Jang, Sang Ho Sohn, Junghwa Kim, "Magnetic Force Between a Multilayered Solenoid and a Magnet", TPT, Vol. 60, #8, Nov. 2022, p. 663.
- A. Kaps, F. Stallmach, "Investigation of the Flux Density of a Solenoid Using the Magnetometer of Smartphones", TPT, Vol. 60, #1, Jan. 2022, p. 70.
- Richard Taylor, "The On-Axis Magnetic Field for a Single, Helical Turn Coil", TPT, Vol. 59, #6, Sept. 2021, p. 455.
- Marcus t. Wilson, "Misconceptions Arising From the Infinite Solenoid Magnetic Field Formula", TPT, Vol. 59, #3, March 2021, p. 213.
- Munho Kwon, Joongwoo Jung, Taehum Jang, Sangho Sohn, "Magnetic Forces Between a Magnet and a Solenoid", TPT, Vol. 58, #5, May 2020, p. 330.
- Francis Xavier Hart, "The Magnetic Field Along the Axis of a Short, Thick Solenoid", TPT, Vol. 56, #2, Feb. 2018, p. 104.
- Juan Jose Lietor-Santos, "Using Experiment and Computer Modeling to Determine the Off-Axis Magnetic Field of a Solenoid", TPT, Vol. 52, #9, Dec. 2014, p. 561.
- Philippe Binder, Kaleonui Hui, and Jesse Goldman, "Magnetic Fields at the Center of Coils", TPT, Vol. 52, #9, Dec. 2014, p. 560.
- Thomas B. Greenslade Jr., "Apparatus Named After Our Academic Ancestors, III", TPT, Vol. 52, #6, Sept. 2014, p. 360.
- Jonathan E. Williams, "Measuring Earth's Local Magnetic Field Using a Helmholtz Coil", TPT, Vol. 52, #4, Apr. 2014, p. 236.
- Nicolas Silva, "Magnetic Field Sensor", TPT, Vol. 50, #6, Sept. 2012, p. 372.
- Erlend H. Graf, "Measuring the Axial Magnetic Field of a Thin Coil", TPT, Vol. 50, #6, Sept. 2012, p. 370.
- Ebe Arndt, "A Magnetic Paradox", TPT, Vol. 44, #8, Nov. 2006, p. 524.
- Farhang Amiri and Rondo N. Jeffery, "Simple Experiments to Study the Earth's Magnetic Field", TPT, Vol. 42, #8, Nov. 2004, p. 458.
- A. Casaca and J.P. Silva, "Magnetic Forces Acting on Rigid Current-Carrying Wires Placed in a Uniform Magnetic Field ", TPT, Vol. 42, #3, March 2004, p. 161.
- Chin-Ta Chia and Ya-Fan Wang, "The Magnetic Field Along the Axis of a Long Finite Solenoid",TPT, Vol. 40, #5, May 2002, p. 288.
- Boon Leong Lan, "Why Do Fields Cancel Inside a Long Cylindrical Shell?", TPT, Vol. 39, #7, Oct. 2001, p. 404.
- Gay B. Stewart, "Measuring Earth's Magnetic Field Simply", TPT, Vol. 38, #2, Feb. 2000, p. 113.
- Michael R. Molnar and Arthur J. Martin, "Ideas for A Magnetic Field Experiment", TPT, Vol. 37, #7, Oct. 1999, p. 443.
- Joseph Priest, "Hands-on Magnetic Field Measurements with a GMR Sensor", TPT, Vol. 37, #6, Sept. 1999, p. 345.
- Danili Rosa and Don Stenton, "Electric and Magnetic Field Mapping", TPT, Vol. 35 #3, Mar. 1997, p. 136.
- Charles A. Sawicki, "Magnetic Field Demonstration/Mystery", TPT, Vol. 35, #4, Apr. 1997, p. 227.
- Danilo Rosa and Don Stenton, "Inexpensive Magnetic Field Mapping Probe", TPT, Vol. 35, #3, Mar. 1997, p. 136.
- Eric R. Dietz and Robert W. Keith, "Inexpensive Magnetic Field Mapping Probe", TPT, Vol. 35, #2, Feb. 1997, p. 112.
- Takao Takeuchi, "Magnetic Field of a Double-Layer Solenoid", TPT, Vol. 35, #5, May 1997, p. 306.
- Colin Terry, "Magnetic Fields in a Slinky", TPT, Vol. 33, #7, Oct. 1995, p. 472.
- An Zhong, "Determine the Magnetic Induction of a Coil with a Hall Element", TPT, Vol. 28, #2, Feb. 1990, p. 123.
- W. G. Delinger, "Magnetic Field Inside a Hole in a Conductor", TPT, Vol. 28, #3, Mar. 1990, p. 234.
- Robert Hetzel and Jim Williams, "Floating Drops", TPT, Vol. 22, #4, Apr. 1984, p. 254.
- W. Eppenstein and S. Maleki, "Magnetic Hysteresis on the Overhead Projector", TPT, Vol. 18, #8, Nov. 1980, p. 614.
- B. Daniels, "Determination of a Small Magnetic Moment and the Horizontal Component of the Earth's Magnetic Field", TPT, Vol. 5, #4, Apr. 1967, p. 177.
- Thomas B. Greenslade, Jr., "Tangent Galvanometer", AJP, Vol. 91, #10, Oct. 2023, p. 839.
- Thomas B. Greenslade, Jr., "Tangent Galvanometer", AJP, Vol. 80, #7, July 2012, p. 637.
- Velimir Labinac, Natasa Erceg, and Dubravka Kotnik-Karuza, "Magnetic Field of a Cylindrical Coil", AJP, Vol. 74, # 7, July 2006, p. 621.
- Oliver Espinosa and Viktor Slusarenko, "The Magnetic Field of an Infinite Solenoid", AJP, Vol. 71, #9, Sept. 2003, p. 953.
- Jason Farley and Richard H. Price, "Field Just Outside a Long Solenoid", AJP, Vol. 69, #7, July 2001, p. 751.
- Lawrence B. Golden, James R. Klein, and Luisito Tongson, "An Introductory Low-cost Magnetic Field Experiment", AJP, Vol. 56, #9, Sept. 1988, p. 846.
- A. J. Kromminga and D. A. Van Baak, "Solid-State Magnetic-Field Transducers and Ampere's Law", AJP, Vol. 56, #7, July 1988, p. 622.
- Maurice Leclerc, "Hall Effect Probe and Ampere's Law", AJP, Vol. 56, #10, Oct. 1988, p. 954.
- P. N. Murgatroyd and M. Belloufi, "Simple Demountable Helmholtz Coils", AJP, Vol. 56, #5, May 1988, p. 478.
- Christopher C. Jones, "Faraday's Law Apparatus for the Freshman Laboratory", AJP, Vol. 55, #12, Dec. 1987, p. 1148.
- H. G. Gnanatilaka and P. C. B. Fernando, "An Investigation of the Magnetic Field in the Plane of a Circular Current Loop", AJP, Vol. 55, #4, Apr. 1987, p. 341.
- Paul A. Lucas, "Modifying Helmholtz Coils to Magnetically Drive a Small Dipole", AJP, Vol. 54, #7, July 1986, p. 666.
- Anthony J. Alfrey, "Deriving Empirical Laws in the Lower Division Physics Lab: Magnetic Field Due to a Current Loop", AJP, Vol. 47, #10, Oct. 1979, p. 918.
- Er-1: Freier and Anderson, A Demonstration Handbook for Physics.
- B-230: "Turns and Area Affect EMF", DICK and RAE Physics Demo Notebook.
- B-025: "Direction of Field", DICK and RAE Physics Demo Notebook.
- Sara Stein, "Magnetic Diversions", The Science Book, p. 243.
- Yaakov Kraftmakher, "1.9, Magnetic Field Measurements", Experiments and Demonstrations in Physics, ISBN 981-256-602-3, p. 31.
- Rudolf F. Graf, "Unfriendly Paper Clip", Safe and Simple Electrical Experiments, p. 95.
- Rudolf F. Graf, "Checking the Magnetic Polarity of a Solenoid", Safe and Simple Electrical Experiments, p. 91.
- Joseph Frick, "# 307 & 308 - The Tangent Compass & The Compass of Sines", Physical Technics: Or Practical Instructions for Making Experiments in Physics and the Construction of Physical Apparatus with the Most Limmited Means, p. 360.
- D. Colson, C. J. Lapp, J. A. Eldridge, "Experiment LVII", 1936 Univ. of Iowa Physics Laboratory Manual, p. 55.
- The Queen Catalogues Vol. II, Catalogue of Electrical Testing Apparatus, p. 20.
Disclaimer: These demonstrations are provided only for illustrative use by persons affiliated with The University of Iowa and only under the direction of a trained instructor or physicist. The University of Iowa is not responsible for demonstrations performed by those using their own equipment or who choose to use this reference material for their own purpose. The demonstrations included here are within the public domain and can be found in materials contained in libraries, bookstores, and through electronic sources. Performing all or any portion of any of these demonstrations, with or without revisions not depicted here entails inherent risks. These risks include, without limitation, bodily injury (and possibly death), including risks to health that may be temporary or permanent and that may exacerbate a pre-existing medical condition; and property loss or damage. Anyone performing any part of these demonstrations, even with revisions, knowingly and voluntarily assumes all risks associated with them.