Related Experiment Video

Updated: Aug 1, 2026

Multifocal Electroretinograms
16:49

Multifocal Electroretinograms

Published on: December 4, 2011

Effects of an ELF (50 Hz, 1 mT) electromagnetic field (EMF) on concentration in visual attention, perception and

M Trimmel1, E Schweiger

  • 1Institute of Environmental Hygiene, University of Vienna, Austria.

Toxicology Letters
|November 20, 1998
PubMed

Related Concept Videos

Induction01:16

Induction

An emf is induced when the magnetic field in a coil is changed by pushing a bar magnet into or out of the coil. emfs of opposite signs are produced by motion in opposite directions, and the directions of emfs are also reversed by reversing poles. The same results are produced if the coil is moved rather than the magnet—it is the relative motion that is important. The faster the motion, the greater the emf. Additionally, there is no emf when the magnet is stationary relative to the coil.
A...
Motional Emf01:22

Motional Emf

Magnetic flux depends on three factors: the strength of the magnetic field, the area through which the field lines pass, and the field's orientation with respect to the surface area. If any of these quantities vary, a corresponding variation in magnetic flux occurs. If the area through which the magnetic field lines are passing changes, then the magnetic flux also changes. This change in the area can be of two types: the flux through the rectangular loop increases as it moves into the magnetic...
Induced Electric Fields: Applications01:27

Induced Electric Fields: Applications

An important distinction exists between the electric field induced by a changing magnetic field and the electrostatic field produced by a fixed charge distribution. Specifically, the induced electric field is nonconservative because it does not work in moving a charge over a closed path. In contrast, the electrostatic field is conservative and does no net work over a closed path. Hence, electric potential can be associated with the electrostatic field but not the induced field. The following...
Back EMF01:24

Back EMF

Generators convert mechanical energy into electrical energy, whereas motors convert electrical energy into mechanical energy. A motor works by sending a current through a loop of wire located in a magnetic field. As a result, the magnetic field exerts a torque on the loop. This rotates a shaft, extracting mechanical work from the electrical current sent in initially. When the coil of a motor is turned, magnetic flux changes through the coil, and an emf (consistent with Faraday's law) is induced.
Applications of EMF Measurements01:26

Applications of EMF Measurements

Electromotive force (EMF) measurements have a broad range of applications in various fields, including chemistry and physics. The electrochemical series, an arrangement of elements in order of their standard electrode potentials, can be determined through EMF measurements. Elements with lower standard potentials can reduce ions of elements with higher standard potentials.The standard cell potential, E°, allows for the calculation of the standard reaction Gibbs energy, ΔG°, and the equilibrium...