Scoping magnetic fields out for prevention

July 11, 2018

Concerns about the effects of magnetic fields on human health require careful monitoring of our exposure to them. Mandatory exposure limits have been defined for electric and hybrid vehicle architectures, in domestic and work environments, or simply to shelter sensitive devices from unintended sources of magnetic disturbance. In a new study published in EPJ Plus, physicists Jose Manuel Ferreira and Joaquim Anacleto from the Trás-os-Montes e Alto Douro University in Portugal develop a method for deriving an approximate value of the circulation around a loop of the magnetic field generated by the flow of electric current in an arbitrarily-shaped wire of a given length.

Magnetic fields are not only ubiquitous; they can also move around. For example, each time an electric current passes through a wire, it generates a magnetic field that changes in tandem with the wire's shape. This was proven by the Danish physicist Hans Christian Ørsted in 1820. Subsequently, Jean-Marie Biot and Félix Savart gave their names to a law describing the magnetic field away from an electric current, which depends on the distance and orientation relative to the direction of current, and the strength of the current.

In this study, the authors set out to adapt Biot-Savart's law, which describes the magnetic field generated by finite wires, to evaluate the circulation of such fields around a closed path or loop. This led the authors to a mathematical formula that, as the finite wire thickness decreases to zero, becomes identical to one of their recent research results expressing the magnetic field circulation as a function of the wire current and of the solid angles between the circulation path and each of the conducting wire's endpoints.

The authors found that the circulation around a closed path of the magnetic field generated by a non-closed portion of circuit was identical to that resulting from the interchange of the portion of circuit with the closed path. The next step would be to produce simple approximations of the magnetic fields generated by a variety of finite-length conductors of various shapes.
-end-
References: J. M. Ferreira and J. Anacleto (2018), The magnetic field circulation counterpart to Biot-Savart's law, Eur. Phys. J. Plus 133:234, DOI 10.1140/epjp/i2018-12097-7

Springer

Related Magnetic Field Articles:

Understanding stars: How tornado-shaped flow in a dynamo strengthens the magnetic field
A new simulation based on the von-Kármán-Sodium (VKS) dynamo experiment takes a closer look at how the liquid vortex created by the device generates a magnetic field.
'Quartz' crystals at the Earth's core power its magnetic field
Scientists at the Earth-Life Science Institute at the Tokyo Institute of Technology report in Nature (Fen.
Brightest neutron star yet has a multipolar magnetic field
Scientists have identified a neutron star that is consuming material so fast it emits more x-rays than any other.
Confirmation of Wendelstein 7-X magnetic field
Physicist Sam Lazerson of the US Department of Energy's Princeton Plasma Physics Laboratory has teamed with German scientists to confirm that the Wendelstein 7-X fusion energy device called a stellarator in Greifswald, Germany, produces high-quality magnetic fields that are consistent with their complex design.
High-precision magnetic field sensing
Scientists have developed a highly sensitive sensor to detect tiny changes in strong magnetic fields.
Brilliant burst in space reveals universe's magnetic field
Scientists have detected the brightest fast burst of radio waves in space to date -- locating the source of the event with more precision than previous efforts.
Optical magnetic field sensor can detect signals from the nervous system
The human body is controlled by electrical impulses in the brain, the heart and nervous system.
What did Earth's ancient magnetic field look like?
New work from Carnegie's Peter Driscoll suggests Earth's ancient magnetic field was significantly different than the present day field, originating from several poles rather than the familiar two.
Just what sustains Earth's magnetic field anyway?
Earth's magnetic field shields us from deadly cosmic radiation, and without it, life as we know it could not exist here.
Ironing out the mystery of Earth's magnetic field
The Earth's magnetic field has been existing for at least 3.4 billion years thanks to the low heat conduction capability of iron in the planet's core.

Earth's Magnetic Field Secrets: An Illusion Mixed With Reality
by Dennis Brooks (Author)

by Msc William Pawluk MD (Author), Caitlin Layne (Author)

by William E. Gray (Author)

Magnetic Fields' 69 Love Songs: A Field Guide (33 1/3)
by LD Beghtol (Author), Ken Emerson (Introduction)

NOW 2 kNOW Electro-Magnetic Fields
by Dr. T G D'Alberto (Author)

The Electromagnetic Field (Dover Books on Physics)
by Dover Publications

Cosmic Magnetic Fields (Cambridge Astrophysics)
by Philipp P. Kronberg (Author)

Magnetic Fields: Expanding American Abstraction, 1960s to Today
by Valerie Cassel Oliver (Author), Lowery Stokes Sims (Author), Erin Dziedzic (Editor), Melissa Messina (Editor)

Solar Magnetic Fields: From Measurements Towards Understanding (Space Sciences Series of ISSI)
by André Balogh (Editor), Edward Cliver (Editor), Gordon Petrie (Editor), Sami Solanki (Editor), Michael Thompson (Editor), Rudolf von Steiger (Editor)

Electricity and Magnetism: An Introduction to the Theory of Electric and Magnetic Fields, 2nd edition
by Oleg D. Jefimenko (Author)

Best Science Podcasts 2018

We have hand picked the best science podcasts for 2018. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.