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प्रश्न
Answer briefly.
Why are microwaves used in radar?
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उत्तर
Microwaves are used in radar systems for identifying the location of distant objects like ships, airplanes, etc.
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संबंधित प्रश्न
Why are microwaves considered suitable for radar systems used in aircraft navigation?
What role dose infra-red radiation play in physical therapy?
Identify the part of the electromagnetic spectrum which is suitable for radar system used in aircraft navigation.
State an additional use of the X-rays waves
Why are infra-red waves often called heat waves? Explain.
State the approximate range of wavelength associated with the ultraviolet rays.
Which part of electromagnetic spectrum is used in radar systems?
Characteristic X-rays may be used to identify the element from which they are being emitted. Can continuous X-rays be used for this purpose?
Is it possible that in a Coolidge tube characteristic Lα X-rays are emitted but not Kα X-rays?
Find the energy, the frequency and the momentum of an X-ray photon of wavelength 0.10 nm.
(Use Planck constant h = 4.14 × 10-15 eVs, speed of light c = 3 × 108 m/s.)
What potential difference should be applied across an X-ray tube to get X-ray of wavelength not less than 0.10 nm? What is the maximum energy of a photon of this X-ray in joule?
(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
X-rays
State the name and the range of wavelength of the invisible electromagnetic waves beyond the red end of the visible spectrum.
Name three radiations and their wavelength range which are invisible and beyond the violet end of the visible spectrum.
Choose the correct option.
Earth’s atmosphere is richest in
Answer briefly.
Can we produce a pure electric or magnetic wave in space? Why?
What are the ultraviolet rays?
Answer briefly.
Give two uses of radio waves.
Light of wavelength `3500A` is incident on two metals A and B whose work functions are 3.2 eV and 1.9 eV respectively. Which metal will emit photoelectrons?
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:
For television broadcasting, the frequency employed is normally
The frequency of e. m waves which is best suited .to observed of radius 3 × 10–4 his of the order of
Find the photon energy in units of ev for electromagnetic wave if waves length 40 m. Given h = 6.63 × 10–34 J.
The ratio of contributions made by the electric field and magnetic field components to the intensity of an EM wave is ______.
Electromagnetic waves with wavelength
- λ1 is suitable for radar systems used in aircraft navigation.
- λ2 is used to kill germs in water purifiers.
- λ3 is used to improve visibility in runways during fog and mist conditions.
Identify and name the part of the electromagnetic spectrum to which these radiations belong. Also arrange these wavelengths in ascending order of their magnitude.
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.
