Understanding Electric and Magnetic Fields
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Electric and magnetic fields (EMF) are invisible lines of force that surround any electrical device that is plugged in and turned on. EMF are made up of waves of electric and magnetic energy moving together (radiating) through space. Electric fields are produced by electric charges and magnetic fields are produced by the flow of current through wires or electrical devices.
EMF is commonly associated with power lines. A person standing directly under a high-voltage transmission line may feel a mild shock when touching something that conducts electricity. These sensations are caused by the strong electric fields from the high-voltage electricity in the lines. They occur only at close range because the electric fields rapidly become weaker as the distance from the line increases.
Many people are concerned about potential adverse health effects. Much of the research about power lines and potential health effects is inconclusive. Despite more than two decades of research to determine whether elevated EMF exposure, principally to magnetic fields, is related to an increased risk of childhood leukemia, there is still no definitive answer. The general scientific consensus is that, thus far, the evidence available is weak and is not sufficient to establish a definitive cause-effect relationship.
EMF is commonly associated with power lines. A person standing directly under a high-voltage transmission line may feel a mild shock when touching something that conducts electricity. These sensations are caused by the strong electric fields from the high-voltage electricity in the lines. They occur only at close range because the electric fields rapidly become weaker as the distance from the line increases.
Many people are concerned about potential adverse health effects. Much of the research about power lines and potential health effects is inconclusive. Despite more than two decades of research to determine whether elevated EMF exposure, principally to magnetic fields, is related to an increased risk of childhood leukemia, there is still no definitive answer. The general scientific consensus is that, thus far, the evidence available is weak and is not sufficient to establish a definitive cause-effect relationship.
Understanding RAdio-frequency waves
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Radio frequency or RF is a frequency or rate of oscillation in the range of 3 Hz to 300 Ghz. This range relates to the frequency of alternating current electrical signals to create and detect radio waves. As this range is beyond the vibration rate that many mechanical systems respond to, RF refers to oscillations in electrical circuits. When the current is input to an antenna, an electromagnetic field is generated that is suitable for wireless broadcasting and/or communications. These frequencies cover the electromagnetic radiation spectrum ranging from nine kilohertz, the lowest allocated wireless communications frequency to thousands of gigahertz. When an RF current is given to an antenna, an electromagnetic field is created that propagates through space.
Properties of Radio Frequency Electrical Signals
the ease with which air can be ionized to create a conductive path across air electromagnetic force that drives the RF current to the surface of conductors known as skin effect ability to appear to flow through paths containing insulating material similar to the dielectric insulator of the capacitor
Properties of Radio Frequency Electrical Signals
the ease with which air can be ionized to create a conductive path across air electromagnetic force that drives the RF current to the surface of conductors known as skin effect ability to appear to flow through paths containing insulating material similar to the dielectric insulator of the capacitor