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प्रश्न
Identify the part of the electromagnetic spectrum used in (i) radar and (ii) eye surgery. Write their frequency range.
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उत्तर
Microwaves are used for the ‘Radar’ system. The frequency range of microwaves is from 1 GHz to 2 GHz and
(ii) Ultraviolet rays (UV rays) are used in eye surgery. The frequency range of UV rays are from 1015 to 1017 Hz
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संबंधित प्रश्न
Given below are some famous numbers associated with electromagnetic radiations in different contexts in physics. State the part of the electromagnetic spectrum to which each belongs.
(a) 21 cm (wavelength emitted by atomic hydrogen in interstellar space).
(b) 1057 MHz (frequency of radiation arising from two close energy levels in hydrogen; known as Lamb shift).
(c) 2.7 K [temperature associated with the isotropic radiation filling all space-thought to be a relic of the ‘big-bang’ origin of the universe].
(d) 5890 Å - 5896 Å [double lines of sodium]
(e) 14.4 keV [energy of a particular transition in 57Fe nucleus associated with a famous high resolution spectroscopic method (Mössbauer spectroscopy)].
State Moseley's law
Give one use of ultraviolet radiation.
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(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 Ultraviolet rays
Give one use of electromagnetic radiations in Infrared radiation.
Answer briefly.
Why light waves travel in a vacuum whereas sound waves cannot?
Arrange the following electromagnetic radiation in the ascending order of their frequencies:
X-rays, microwaves, gamma rays, radio waves
