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Electromagnetic Waves — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsElectromagnetic Waves3 Marks
Question
  1. Name the em waves which are suitable for radar systems used in aircraft navigation. Write the range of frequency of these waves.
  2. If the earth did not have atmosphere, would its average surface temperature be higher or lower than what it is now? Explain.
  3. An em wave exerts pressure on the surface on which it is incident. Justify.
✓

Answer

  1. Frequency range $10^{10}Hz$ to $10^{12}Hz.$
  2. Average surface temperature will be lower. This is because there will be no greenhouse effect in absence of atmosphere.
  3. An electromagnetic wave exerts pressure on the surface on which it is incident because these waves carry both energy and momentum.

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