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Electromagnetic Waves — Physics STD 12 Science — Question

Rajasthan BoardEnglish MediumSTD 12 SciencePhysicsElectromagnetic Waves5 Marks
Question
Electromagnetic waves with wavelength:
  1. $\lambda _1$ is used in satellite communication.
  2. $\lambda _2$ is used to kill germs in water purifies.
  3. $\lambda _3$ is used to detect leakage of oil in underground pipelines.
  4. $\lambda _4$ is used to improve visibility in runways during fog and mist conditions.
  1. Identify and name the part of electromagnetic spectrum to which these radiations belong.
  2. Arrange these wavelengths in ascending order of their magnitude.
  3. Write one more application of each.
✓

Answer

  1.  
  1. In satellite communications, microwave is widely used. Hence $\lambda _1,$ is the wavelength of microwave.
  2. In water purifier, ultraviolet rays are used to kill germs. So, $\lambda _2$ is the wavelength of $UV$ rays.
  3. $X-$rays are used to detect leakage of oil in underground pipelines. So, $\lambda _{3 }$ is the wavelength of $X-$rays.
  4. Infrared rays are used to improve visibility on runways during fog and mist conditions. So, it is the wavelength of infrared waves.
  1. Wavelength of $X-$rays $ < $ wavelength of $UV < $ wavelength of infrared $ < $ wavelength of microwave.
$\Rightarrow\ \lambda_3<\lambda_2<\lambda_4<\lambda_1$
  1. Radiation Uses
    $\gamma-$ rays Givens informations on nuclear structure, medical treatment etc.
    $X-$rays Medical diagnosis and treatment study of crystal structure, inductrial radiograph.
    $UV-$rays Preserce food, sterlizing the surgical instruments, detecting the invisible writings, finger prints etc.
    Visible light To see objects.
    Infrated rays To treat, muscular strain for taking photogtaphy during the fog, haze etc.
    Micro wave and radio wave In radar and telecommunication.

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