Electromagnetic induction can be defined as the production of electromotive voltage or force across an electrical conductor when it dynamically interacts with a magnetic field. There are numerous uses of electromagnetic induction, for example, in electromagnetic elements such as transformers and inductors, electric motors, generators, and transcranial magnetic stimulators.
Applications of Electromagnetic Induction
Electromagnetic induction is an extremely useful phenomenon with various applications. It’s applied in the creation of eddy currents, which are swirling currents set up in conductors in response to changing magnetic fields. Electrons in the field swirl in a perpendicular plane to the magnetic field causing loss or transformation of energy, for example, kinetic energy into heat energy. One application of eddy currents is the train braking system that exposes metallic wheels to a magnetic field and causes the formation of eddy currents that act to slow the train down. Electric generators transform mechanical energy to electrical energy using motors. A current is passed through a wire coil found at the heart of the motors; thus, causing the coil to spin when the magnetic field interacts with the current. A coil of wire spun within a magnetic field at a particular constant rate produces AC electricity. Electric coils can produce emf when changing current is passed through them. A changing magnetic field is produced, which induces an emf in the coil. When two coils are next to one another, the one with a current passing through it generates a magnetic field, and magnetic flux produced passes through the other coil. Making variations to the current alters the magnetic flux and induces emf. Similarly, in self-inductances, the emf that is induced is proportionate to variations in flux and changes in current in the original coil.
Inductors are used to manufacture transcranial magnetic stimulators that are used to stimulate small regions of the brain by placing magnetic coils or field generators near the head of the person receiving the treatment. The magnetic coils are connected to a pulse generator that delivers tiny amounts of electric currents in the particular region of the brain where they’re placed in a process known as electromagnetic induction. In this process, the magnetic fields induced alter the excitability of neurons close to the electrodes such that cells close to the anode become more excited than those near the cathode ("Applications of electromagnetic induction", 1999).
Although brain imaging studies have led to the development of better understanding of neural networks, this knowledge is limited and has raised ethical considerations concerning the justification of targeting particular region of the brain during various treatments. This is mainly because very little evidence exists about the areas that are concerned. There are concerns over the use of transcranial stimulation to alter memories, cognition, and brain development. Enhancement of cognition using this method may be considered as cheating by many people. Additionally, forced transcranial stimulation could be used to coerce people to receive it. Along such lines, police could use this treatment method to detect deception because it interferes with an individual’s ability to lie. Non-clinical applications of this treatment mechanism has become widespread and many people have raised concerns over the risks that could be involved, especially with large amounts of current being used to alter memories and the brain functioning mechanism (Lapenta, Valasek, Brunoni, & Boggio, 2014). All in all, the primary side effects associated with transcranial stimulation include headaches, mild hearing, and skin tenderness.
References
Applications of electromagnetic induction. (1999). Physics.bu.edu. Retrieved 26 June 2016, from http://physics.bu.edu/~duffy/PY106/Electricgenerators.html
Lapenta, O., Valasek, C., Brunoni, A., & Boggio, P. (2014). An ethical discussion of the use of transcranial direct current stimulation for cognitive enhancement in healthy individuals: A fictional case study. Psychology & Neuroscience, 7(2), 175-180. http://dx.doi.org/10.3922/j.psns.2014.010
