/ Preparation Physics Electromagnetic Waves
An Electromagnetic spectrum consists of the entire range of all types of electromagnetic radiations based on their wavelengths, frequencies, energy and momentum. From low frequency to high frequency, each category of wave is included in this vast spectrum where each wave travels at the speed of light (3 * 10^8 m/s). This topic is a continuation of the topic electromagnetic waves and is extremely important for the candidates aspiring to prepare for JEE MAINS. Different waves in this spectrum have different uses as per their range of frequencies, which are discussed in the article given below.
- Key Terms
- Types of Electromagnetic Waves
- Real-World Applications
- Physics Class 12 NCERT Solutions
Key Terms
Here are a few essential terms related to this topic that the candidates need to study thoroughly in order to clear their fundamental concepts:
- Wavelength:
This is the distance between two peaks of a wave.
SI Unit - meters
Denoted by the symbol λ.
- Frequency:
This is the number of wave cycles per second.
SI Unit - Hz
Denoted by the symbol ν.
- Energy:
The formula for energy is E=hν
Where, h = 6.63 × 10⁻³⁴ Js (Planck’s Constant)
- Amplitude:
This is referred to the maximum strength of the electric or magnetic field in a wave. In simple terms, the peak of the wave is called amplitude.
Types of Electromagnetic Waves
Mentioned below are the commonly recognized categories of electromagnetic waves in the EM spectrum arranged as per their increasing order of wavelength and frequency:
Real-World Applications
This spectrum has numerous daily life applications and plays a very huge role in human existence. Some core applications of the EM spectrum are as follows:
- Radio Signals and Mobile Phones
- Bluetooth and Wifi
- Microscopes and Telescopes
- Microwaves and Heaters
- Sterilization
- Cameras and Projectors
- TV screens
- Satellites
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Commonly asked questions
Are electromagnetic waves harmful to the human body?
It depends on the frequency of the wave. Rays such as Gamma rays, X-Rays etc. have higher frequencies which can lead to harmful impacts if exposed to the human body. These kind of rays cannot be even produced easily unlike low frequency rays.
Why are some electromagnetic waves invisible to the naked eye?
There are different types of electromagnetic waves and each of them have different wavelengths. Human eye can only see the light rays which have a minimum wavelength of around 400-700nm. Rays which don't meet this threshold will eventually not be visible to the humans.
What is the IR Radiation?
Infrared radiation is a part of the electromagnetic spectrum which is specifically used in night detection techniques to enhance visibility. They have a wavelength of around 700 nm to 1 mm and have a frequency range of around 10^12 Hz.
Physics Electromagnetic Waves Exam
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