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प्रश्न
Name the radiations of wavelength just shorter than 4 × 10-7 m.
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उत्तर
Ultraviolet radiations are shorter than 4 × 10-7 m = `(4 xx 10^-7)/(10^-10) = 4000` Å
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संबंधित प्रश्न
Give the range of wavelength of the electromagnetic waves visible to us.
Name two sources, each of infrared radiations and ultraviolet radiations.
X-ray from a Coolidge tube is incident on a thin aluminium foil. The intensity of the X-ray transmitted by the foil is found to be I0. The heating current is increased to increase the temperature of the filament. The intensity of the X-ray transmitted by the foil will be
(a) zero
(b) < I0
(c) I0
(d) > I0
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.
If the operating potential in an X-ray tube is increased by 1%, by what percentage does the cutoff wavelength decrease?
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
Answer briefly.
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Write two uses of the following radiation.
Gamma rays
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- Identify the electromagnetic waves.
- Write one source for each of them.
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- 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.
