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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
State the approximate range of wavelength associated with the ultraviolet rays.
Name three properties of ultraviolet radiations which are similar to visible light.
X-ray and visible light travel at the same speed in vacuum. Do they travel at the same speed in glass?
Cutoff wavelength of X-rays coming from a Coolidge tube depends on the
(a) target material
(b) accelerating voltage
(c) separation between the target and the filament
(d) temperature of the filament.
Find the energy, the frequency and the momentum of an X-ray photon of wavelength 0.10 nm.
(Use Planck constant h = 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
-
- Calculate the speed of the wave.
- Name the medium through which it is traveling.
Name the radiation of the electromagnetic spectrum which is used for the following:
For taking photographs of the sky during the night and foggy conditions . Give the frequency range
The area to be covered for T.V telecast is doubled then the height of transmitting antenna (T.V tower) will have to be:-
What is time period of the light for which the eye is most sensitive?
What happens to the intensity of light from a bulb if the distance from the bulb is doubled? As a laser beam travels across the length of a room, its intensity essentially remains constant. What geometrical characteristic of LASER beam is responsible for the constant intensity which is missing in the case of light from the bulb?
