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प्रश्न
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उत्तर
The electromagnetic radiations of wavelength from 100 Å to 4000 Å are called the ultraviolet radiations.
Detection: If the different radiations from the red part of the spectrum to the violet end and beyond it are made incident on the silver-chloride solution, it is observed that from the red end to the violet, the solution remains almost unaffted. However just beyond the violet end, it first turns violet and finally it becomes dark brown (or black). thus, there exist certain radiations beyond the violet end of the spectrum, which are chemically more active than the visible light. Thses radiations are called the ultraviolet radiations.
Two properties of ultraviolet radiation:
1. Ultraviolet radiation can pass through quartz, but they are absorbed by glass.
2. They are usually scattered ny the dust particles present in the atmosphere.
one use of ultraviolet radiation:
in producing, Vitamin D, in food of plans and animals.
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संबंधित प्रश्न
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?
State the approximate range of wavelength associated with visible light.
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.)
Write the range of the wavelength of the following electromagnetic radiations:
(a) Infrared rays
(b) Ultraviolet rays
(c) γ -rays
Write one use of each of the above.
| Gamma rays | D | C | Visible light | B | A |
The above table shows different parts of the electromagnetic spectrum.
(a) Identify the parts of the spectrum marked as A, B, C and D.
(b) Which of the radiations A or B has the higher frequency?
(c) State two properties which are common to all parts of the electromagnetic spectrum.
(d) Name one source of each of the radiation of electromagnetic spectrum.
(e) Name one detector for each of the radiation.
(f) Name one use of each of the radiation.
Define the term "Intensity" in the photon picture of electromagnetic radiation.
A car is moving towards a high cliff. The car driver sounds a horn of frequency f. The reflected sound heard by the driver has a frequency 2f. If v be the velocity of sound, then the velocity of the car, in the same velocity units, will be:
The area to be covered for T.V telecast is doubled then the height of transmitting antenna (T.V tower) will have to be:-
The half-value thickness of an absorber is defined as the thickness that will reduce exponentially the intensity of a beam of particles by a factor of 2. The half-value thickness in (µm) for lead assuming X-ray beam of wavelength 20 pm, µ = 50 cm-1 for X-rays in lead at wavelength λ = 20 pm, is ______ µm.
How are the electric and magnetic fields oriented in an electromagnetic wave?
