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प्रश्न
Name the scientist who discovered Microwaves
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उत्तर
Hertz
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संबंधित प्रश्न
Name the radiations of wavelength just longer than 8 × 10-7m.
Why is exposure to X-rays injurious to health but not exposure to visible light, when both are electromagnetic waves?
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 distance between the cathode (filament) and the target in an X-ray tube is 1.5 m. If the cutoff wavelength is 30 pm, find the electric field between the cathode and the target.
(Use Planck constant h = 6.63 × 10-34 Js= 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
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State two uses of infrared radiations.
Answer briefly.
Can we produce a pure electric or magnetic wave in space? Why?
Answer briefly.
What is a carrier wave?
The fundamental frequency of an open organ pipe is 300 Hz. The first overtone of this pipe has same frequency as first overtone of a closed organ pipe. If speed of sound is 330 m/s, then the length of closed organ pipe is:
The frequency of e. m waves which is best suited .to observed of radius 3 × 10–4 his of the order of
