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प्रश्न
Give one use of ultraviolet radiation.
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उत्तर
Ultraviolet radiations are used for detecting the purity of gems, eggs, ghee etc.
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संबंधित प्रश्न
How are infrared waves produced?
For harder X-rays,
(a) the wavelength is higher
(b) the intensity is higher
(c) the frequency is higher
(d) the photon energy is higher.
Find the maximum potential difference which may be applied across an X-ray tube with tungsten target without emitting any characteristic K or L X-ray. The energy levels of the tungsten atom with an electron knocked out are as follows.
| Cell containing vacancy | K | L | M |
| Energy in keV | 69.5 | 11.3 | 2.3 |
The wavelength of Kα X-ray of tungsten is 21.3 pm. It takes 11.3 keV to knock out an electron from the L shell of a tungsten atom. What should be the minimum accelerating voltage across an X-ray tube having tungsten target which allows production of Kα X-ray?
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
Give one use of electromagnetic radiations in Infrared radiation.
Answer briefly.
What are radio waves?
Answer briefly.
Name the most harmful radiation entering the Earth's atmosphere from outer space.
The frequency of e. m waves which is best suited .to observed of radius 3 × 10–4 his of the order of
Identify the electromagnetic wave whose wavelength range is from about 10-3 m to about 10-1 m. Write one use of this.
Identify the part of the electromagnetic spectrum which:
- produces the heating effect.
- is absorbed by the ozone layer in the atmosphere.
- is used for studying crystal structure.
Write any one method of the production of each of the above radiations.
