Gelombang Elektromagnetik adalah gelombang yang dapat merambat walau tidak ada medium. Energi elektromagnetik merambat dalam gelombang dengan beberapa karakter yang bisa diukur, yaitu: panjang gelombang/wavelength, frekuensi, amplitude/amplitude, kecepatan. Amplitudo adalah tinggi gelombang, sedangkan panjang gelombang adalah jarak antara dua puncak. Frekuensi adalah jumlah gelombang yang melalui suatu titik dalam satu satuan waktu. Frekuensi tergantung dari kecepatan merambatnya gelombang. Karena kecepatan energi elektromagnetik adalah konstan (kecepatan cahaya), panjang gelombang dan frekuensi berbanding terbalik. Semakin panjang suatu gelombang, semakin rendah frekuensinya, dan semakin pendek suatu gelombang semakin tinggi frekuensinya.
Energi elektromagnetik dipancarkan, atau dilepaskan, oleh semua masa di alam semesta pada level yang berbedabeda. Semakin tinggi level energi dalam suatu sumber energi, semakin rendah panjang gelombang dari energi yang dihasilkan, dan semakin tinggi frekuensinya. Perbedaan karakteristik energi gelombang digunakan untuk mengelompokkan energi elektromagnetik.
Ciri-ciri gelombang
elektromagnetik :
Dari uraian tersebut diatas dapat
disimpulkan beberapa ciri gelombang elektromagnetik adalah sebagai berikut:
1. Perubahan medan listrik dan medan magnetik terjadi
pada saat yang bersamaan,sehingga kedua medan memiliki harga maksimum dan
minimum pada saat yang sama dan pada tempat yang sama.
2. Arah
medan listrik dan medan magnetik saling tegak lurus dan keduanya tegak lurus
terhadap arah rambat gelombang.
3. Dari
ciri no 2 diperoleh bahwa gelombang elektromagnetik merupakan gelombang
transversal.
4. Seperti halnya gelombang pada umumnya, gelombang
elektromagnetik mengalami peristiwa pemantulan, pembiasan, interferensi, dan
difraksi. Juga mengalami peristiwa polarisasi karena termasuk gelombang
transversal.
5. Cepat
rambat gelombang elektromagnetik hanya bergantung pada sifat-sifat listrik dan
magnetik medium yang ditempuhnya.
Perbedaan interval/jarak panjang gelombang dan frekuensi gelombang yang disusun dalam bentuk tabel panjang gelombang dan frekuensi secara berurutan disebut spektrum gelombang elektromagnetik. Gelombang radio memiliki frekuensi terendah, sedangkan sinar gamma memiliki frekuensi tertinggi. Perhatikan Gambar berikut!
rumus
SUMBER GELOMBANG ELEKTROMAGNETIK
- Osilasi listrik.
- Sinar matahari ® menghasilkan sinar infra merah.
- Lampu merkuri ® menghasilkan ultra violet.
- Penembakan elektron dalam tabung hampa pada keping logam ®menghasilkan sinar X (digunakan untuk rontgen).
Inti atom yang tidak stabil menghasilkan sinar gamma.
SPEKTRUM GELOMBANG ELEKTROMAGNETIK
Susunan semua bentuk gelombang elektromagnetik berdasarkan panjang gelombang dan frekuensinya disebut spektrum elektromagnetik. Gambar spectrum elektromagnetik di bawah disusun berdasarkan panjang gelombang (diukur dalam satuan _m) mencakup kisaran energi yang sangat rendah, dengan panjang gelombang tinggi dan frekuensi rendah, seperti gelombang radio sampai ke energi yang sangat tinggi, dengan panjang gelombang rendah dan frekuensi tinggi seperti radiasi X-ray dan Gamma Ray.
gambar spektrum elektromagnetik.
Sifat dan Spektrum Gelombang Elektromagnetik
Sebagaimana gelombang mekanik, gelombang elektromagnetik juga memiliki sifat yang kurang lebih hampir sama. Adapun sifat dari gelombang elektromagnetik, antara lain, dapat merambat di ruang hampa, merupakan gelombang transversal, mengalami pemantulan (refleksi), mengalami pembiasan( refraksi), mengalami interferensi, mengalami lenturan (difraksi), dan arah rambatannya tidak ditentukan oleh medan listrik maupun medan magnet.
Cahaya, gelombang radio, sinar-X, dan sinar gamma adalah contoh dari gelombang elektromagnetik. Berbagai jenis gelombang elektromagnetik tersebut hanya berbeda dalam frekuensi dan panjang gelombangnya. Hubungan kecepatan perambatan gelombang, frekuensi, dan panjang gelombang dinyatakan sebagai berikut.
Perbedaan interval/jarak panjang gelombang dan frekuensi gelombang yang disusun dalam bentuk tabel panjang gelombang dan frekuensi secara berurutan disebut spektrum gelombang elektromagnetik. Gelombang radio memiliki frekuensi terendah, sedangkan sinar gamma memiliki frekuensi tertinggi. Perhatikan Gambar berikut!
rumus
Cepat Rambat Gelombang Elektromagnetik
c = cepat rambat gelombang elektromagnetik (m/s)
μo = permeabilitas vakum = 4 π × 10-7 WbA-1m-1
εo = permitivitas vakum = 8,85 × 10-12 C2N-1m-2
μo = permeabilitas vakum = 4 π × 10-7 WbA-1m-1
εo = permitivitas vakum = 8,85 × 10-12 C2N-1m-2
Hubungan Cepat Rambat Gelombang Elektromagnetik,
Kuat Medan Listrik
dan Kuat Medan Magnet
.png)
.png)
Laju Energi Rata-Rata
.png)
.png)
Intensitas Gelombang Elektromagnetik
.png)
.png)
BAHASA INGGRIS
electromagnetic wavesElectromagnetic waves are waves that can propagate even if there is no medium. Electromagnetic energy travels in waves with some characters that can be measured, namely: wavelength / wavelength, frequency, amplitude / amplitude, speed. Wave amplitude is high, while the wavelength is the distance between the two peaks. Frequency is the number of waves that pass a point in one unit of time. The frequency depends on the speed of the wave climbed. Because of the speed of electromagnetic energy is constant (speed of light), wavelength and frequency is inversely proportional. The longer a wave, the lower the frequency, the shorter the wave and the higher the frequency.
Electromagnetic energy emitted, or released, by all the time in the universe in which different levels. Higher levels of energy in an energy source, the lower the wavelength of the energy produced, and the higher the frequency. Differences in the characteristics of the wave energy is used to classify electromagnetic energy.
The characteristics of electromagnetic waves:
From the description above we can conclude some characteristics of electromagnetic waves is as follows:
1. Changes in the electric field and magnetic field occurs at the same time, so that the two fields have a maximum and minimum prices at the same time and the same place.
2. Direction of the electric field and magnetic field perpendicular to each other and both perpendicular to the direction of wave propagation.
3. No. 2 is obtained from the characteristic that electromagnetic waves are transverse waves.
4. Like the waves in general, an incident electromagnetic wave reflection, refraction, interference, and diffraction. As well as including an incident polarization of transverse waves.
5. The propagation of electromagnetic waves depends only on the properties of electrical and magnetic medium by which this occurred.
SOURCE ELECTROMAGNETIC WAVES
1. Electrical oscillations.
2. sun produces infrared rays.®
3. mercury lamps produce ultra-violet.®
4. produce X-rays (used for x-rays).®Shooting electrons in a vacuum tube on the metal pieces Unstable nuclei that produce gamma rays.
ELECTROMAGNETIC WAVE SPECTRUM
The composition of all forms of electromagnetic waves by their wavelengths and frequencies called the electromagnetic spectrum. Electromagnetic spectrum picture below is based on the wavelength (measured in units _m) includes a range of very low energy, with high wavelength and low frequency, such as radio waves to very high energy, with a low wavelength and high frequency radiation such as X -ray and Gamma Ray.
electromagnetic spectrum picture.
The characteristics of electromagnetic waves:
From the description above we can conclude some characteristics of electromagnetic waves is as follows:
1. Changes in the electric field and magnetic field occurs at the same time, so that the two fields have a maximum and minimum prices at the same time and the same place.
2. Direction of the electric field and magnetic field perpendicular to each other and both perpendicular to the direction of wave propagation.
3. No. 2 is obtained from the characteristic that electromagnetic waves are transverse waves.
4. Like the waves in general, an incident electromagnetic wave reflection, refraction, interference, and diffraction. As well as including an incident polarization of transverse waves.
5. The propagation of electromagnetic waves depends only on the properties of electrical and magnetic medium by which this occurred.
SOURCE ELECTROMAGNETIC WAVES
1. Electrical oscillations.
2. sun produces infrared rays.®
3. mercury lamps produce ultra-violet.®
4. produce X-rays (used for x-rays).®Shooting electrons in a vacuum tube on the metal pieces Unstable nuclei that produce gamma rays.
ELECTROMAGNETIC WAVE SPECTRUM
The composition of all forms of electromagnetic waves by their wavelengths and frequencies called the electromagnetic spectrum. Electromagnetic spectrum picture below is based on the wavelength (measured in units _m) includes a range of very low energy, with high wavelength and low frequency, such as radio waves to very high energy, with a low wavelength and high frequency radiation such as X -ray and Gamma Ray.
electromagnetic spectrum picture.
Nature of Electromagnetic Waves and Spectrum
As a mechanical wave, electromagnetic waves also have properties more or less similar. As for the nature of electromagnetic waves, among others, can propagate in a vacuum, a transverse wave, having reflection (reflection), having refraction (refraction), experiencing interference, experiencing bending (diffraction), and the direction is not determined by the knock-on electric field or fields magnet.
Light, radio waves, X-rays, and gamma rays are examples of electromagnetic waves. Various types of electromagnetic waves are different only in frequency and wavelength. Relationships wave propagation velocity, frequency, and wavelength is expressed as follows.
Interval difference / wavelength spacing and frequency tables were arranged in the form of wavelength and frequency respectively called the spectrum of electromagnetic waves.Radio waves have the lowest frequency, while the gamma rays have the highest frequency. Note the following picture!
Creep fast Electromagnetic Waves
where
c = velocity of electromagnetic waves (m / s)
μo = permeability of vacuum = 4 π × 10-7 WBA-1m-1
εo = permittivity of vacuum = 8.85 × 10-12 C2N-1m-2
Creep Fast relationships Electromagnetic Waves,
Strong Electric Field
and Strong Magnetic Field
where
c = velocity of electromagnetic waves (m / s)
μo = permeability of vacuum = 4 π × 10-7 WBA-1m-1
εo = permittivity of vacuum = 8.85 × 10-12 C2N-1m-2
Creep Fast relationships Electromagnetic Waves,
Strong Electric Field
and Strong Magnetic Field
Average rate of energy
Intensity Electromagnetic Waves
Tidak ada komentar:
Posting Komentar