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प्रश्न
Answer briefly.
Name the most harmful radiation entering the Earth's atmosphere from outer space.
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उत्तर
Name the most harmful radiation entering the Earth's atmosphere from outer space – Ultraviolet radiation
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संबंधित प्रश्न
Optical and radio telescopes are built on the ground but X-ray astronomy is possible only from satellites orbiting the earth. Why?
The wavelengths for the light of red and blue colours are roughly 7.8 × `10^7` m and 4.8 × `10^7` m respectively.
(a) Which colour has the greater speed in vacuum?
(b) Which colour has the greater speed in glass?
Arrange the following radiations in the order of their increasing wavelength:
X-rays, infrared rays, ratio waves, gamma ray and microwaves.
Which radiation is used for satellite communication?
A wave has a wavelength of 10-3 nm. Name the wave.
State the approximate range of wavelength associated with infrared rays.
How are X-rays produced?
Can X-rays be polarised?
The energy of a photon of a characteristic X-ray from a Coolidge tube comes from
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).
Find the cutoff wavelength for the continuous X-rays coming from an X-ray tube operating at 30 kV.
(Use Planck constant h = 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
The short-wavelength limit shifts by 26 pm when the operating voltage in an X-ray tube is increased to 1.5 times the original value. What was the original value of the operating voltage?
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
Name the scientist who discovered radio waves
To which regions of the electromagnetic spectrum do the following wavelengths belong:
(a) 250 nm
(b) 1500 nm
Gamma rays and radio waves travel with the same velocity in free space. Distinguish between them in terms of their origin and the main application.
State three properties of infrared radiations similar to that of visible light.
Give one use of electromagnetic radiation in Microwaves.
What is the wavelength of the wave whose frequency is 1012 Hz? Name the electromagnetic wave.
What are the ultraviolet rays?
Answer briefly.
Give two uses of ultraviolet rays.
Answer briefly.
Why high-frequency carrier waves are used for the transmission of audio signals?
For television broadcasting, the frequency employed is normally
The ozone layer absorbs
Find the photon energy in units of ev for electromagnetic wave if waves length 40 m. Given h = 6.63 × 10–34 J.
The electric field intensity produced by the radiations coming from 100 W bulb at a 3 m distance is E. The electric field intensity produced by the radiations coming from 50 W bulb at the same distance is ______.
Which is the correct ascending order of wavelengths?
Assertion (A): Ultraviolet radiations is scattered more as compared to the microwave radiations.
Reason (R): Wavelength of ultraviolet radiation is more than the wavelength of microwave radiation.
What is the wavelength range of electromagnetic radiation used in radio broadcast?
Name two electromagnetic waves of wavelength smaller than that of violet light.
