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प्रश्न
Electromagnetic waves of wavelengths λ1, λ2 and λ3 are used in a radar system, in water purifiers and in remote switches of TV, respectively.
- Identify the electromagnetic waves.
- Write one source for each of them.
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उत्तर
(i)
- Wavelength λ1 corresponds to Microwaves.
- Wavelength λ2 corresponds to Ultraviolet waves.
- Wavelength λ3 corresponds to Infrared waves.
(ii)
- Source of microwaves: Klystron/magnetron valves.
- Source of ultraviolet waves: Movement of electrons in atoms from higher energy level to lower energy level.
- Source of infrared waves: Vibration of atoms and molecules.
संबंधित प्रश्न
What is the range of the wavelength of the following electromagnetic waves?
(a)X-rays,
What do you understand by the invisible spectrum?
Name the waves produced by the changes in the nucleus of an atom.
Is it possible that in a Coolidge tube characteristic Lα X-rays are emitted but not Kα X-rays?
Frequencies of Kα X-rays of different materials are measured. Which one of the graphs in the figure may represent the relation between the frequency v and the atomic number Z ?

For a given material, the energy and wavelength of characteristic X-rays satisfy
(a) E(Kα) > E(Kβ) > E(Kγ)
(b) E(Mα) > E(Lα) > E(Kα)
(c) λ(Kα) > λ(Kβ) > λ(Kγ)
(d) λ(Mα) > λ(Lα) > λ(Kα).
The potential difference applied to an X-ray tube is increased. As a result, in the emitted radiation,
(a) the intensity increases
(b) the minimum wavelength increases
(c) the intensity remains unchanged
(d) the minimum wavelength decreases.
Name two sources of infrared radiation.
Answer briefly.
Why light waves travel in a vacuum whereas sound waves cannot?
Write two uses of the following radiation.
Gamma rays
