HERTZ'S TRIAL ABOUT ELECTROMAGNETIC WAVES
Heinrich Hertz was the first to test Maxwell's hypothesis about electromagnetic waves. Hertz's experiments have proven the truth of Maxwell's hypothesis. Then finally his name was set as a unit of frequency in SI namely HERTZ (Hz).
Schematic diagram of Hertz experiments
Through this experiment Hertz managed to generate electromagnetic waves and was detected by the recipient. This experiment succeeded in proving that electromagnetic waves which initially only form the theoretical formulation of Maxwell, actually exist at the same time confirm Maxwell's theory of electromagnetic waves.
Properties of electromagnetic waves:
Electromagnetic waves can propagate in space without a medium (Vacuum)
Is a transverse wave
It has no electric charge so it moves straight in a magnetic or electric field
Can experience reflection (reflection), refraction (refraction), integration (interference), flexing (diffraction), polarization
Changes in the electric and magnetic fields occur simultaneously, so that the electric and magnetic fields are in phase and directly proportional
ELECTROMAGNETIC WAVE SPECTRUM
The product of wavelength (l) with wave frequency (f) is equal to fast wave propagation (c). Formulated as follows.
The arrangement of all electromagnetic wave forms based on their wavelength and frequency is called the electromagnetic spectrum. The electromagnetic spectrum image below is arranged in wavelength (measured in _m units) covering a very low energy range, with high wavelengths and low frequencies, such as radio waves to very high energy, with low wavelengths and high frequencies such as X radiation -ray and Gamma Ray.
Relationship Frequency (f), Wavelength (), and electromagnetic wave propagation fast (c):
Frequency Relationship
Examples of electromagnetic spectrum:
Radio Wave
The radio waves are classified according to wavelength or frequency. If the wavelength is high, then the frequency must be low or vice versa. Radio wave frequencies start from 30 kHz and up and are grouped according to their frequency widths. Radio waves are produced by electrical charges which are accelerated through the lead wires. These charges are generated by a series of electronics called oscillators.
These radio waves are transmitted from the antenna and received by the antenna as well. You cannot hear the radio directly, but the radio receiver will first convert the wave energy to sound energy.
Micro wave
Microwaves (microwaves) are radio waves with the highest frequency above 3 GHz. If microwaves are absorbed by an object, a heating effect will appear on the object. If food absorbs microwave radiation, it gets hot in a very short interval of time. This process is used in a microwave oven to cook food quickly and economically.
Microwaves are also used on RADAR (Radio Detection and Ranging) aircraft. RADAR means finding and tracing an object using microwaves. Radar aircraft utilize the nature of microwave reflection. Because the electromagnetic wave velocity is fast c = 3 X 108 m / s, then by observing the time interval between transmission and reception.
The radar antenna can rotate in all directions which can function as a transmitter and transmitter of electromagnetic waves. If the time interval between sending the pulse to the target and receiving the reflected pulse from the target is t, then the distance of the target to the center s can be determined by the formula.