PresentationOf
biophysics
ByAbidAlishah
ELECTROMAGNETICFIELD
•The mutual interaction of electric and magnetic fields produces
an electromagnetic field.
•Electromagneticfieldpropagatesinwaveformat the speed of
light
Sturcture
•Continuousstructure
•Classically, electric and magnetic fields are thought of as being produced
by smooth motions of chargedobject
•. For example, oscillating charges produce variations in electric and
magnetic fields that may beviewed in a ‘smooth’, continuous, wavelike
fashion.
•in this case, energy is viewed as being transferredcontinuously through
the electromagnetic field between any two locations.
Discrete structure
The electromagnetic field may be thought of in a more 'coarse' way.
Experiments reveal that in somecircumstances electromagnetic energy
transfer is better described as being carried in the form of packets
called quanta (in this case, photons) with a fixed frequency. Planck‘s
relation links the photon energy Eof a photon to its frequency f
through the equation:[5]
E=hf
Equations:
•There are four main equations in electromagnetic theory.
•i)Gauss Law:
•It describes the electric field around a point charge.
•Total flux line in any area is equal toq/ϵ
•Gauss Law =∫E.dA=q/ϵ
•ii) Gauss law for magnetism:
•Total of magnetic flux is zero.
•Hence,∫B.dA=0
Equations:
•iii) Faraday’s law of induction:
•A change of electric field causes a change in the rate of change of flux.
•Hence,∫E.dl=−d/dt(∫B.dA)
•iv) Ampere-Maxwell Law:
•∫B.dl=μ(I+d/dt(ϵ∫E.dA))
Applications:
•1.Medical system:
•Most of the advanced medical equipment is based on the principle of
electromagnetism. Medical equipment such as hyperthermia treatments
for cancer, magnetic resonance imaging and implants work on the principle
of electromagnetism.
•X-ray equipment, scanners all are the most common devices useful in
medical services. These devices are based on electromagnetism.
Electromagneticfield
oftheheart
•Ourthoughtsandemotionsaffecttheheart’smagneticfield
•Whichenergeticallyaffectsthoseinourenvironment
•Whetherornotweareconciousofit
Applications
2.Household Appliances:
Lights,fans,Home security system, electric speaker all work on the
principle of electromagnetism.
3.Communication System:
In the case of mobile phones or any communication system sound
energy is converted to electromagnetic energy. Now the radio
transmitters transfer the electromagnetic energy to the receiver. At the
receiver end, the electromagnetic energy again converted to sound
energy
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