🔬 Science & TechnologyUPSC 2011Space & Space Technology

A layer in the Earth’s atmosphere called Ionosphere facilitates radio communication. Why?1. The presence of ozone causes the reflection of radio waves to Earth.2. Radio waves have a very long wavelength.Which of the statements given above is/are correct?

a1 only
b2 only
cBoth 1 and 2
dNeither 1 nor 2
✓ Correct answer: d) Neither 1 nor 2
ExplanationStatement 1 is incorrect: The presence of ions, and not ozone, in the Ionosphere is responsible for radio communication.Ozone is primarily present in the Stratosphere and not in the Ionosphere.Statement 2 is incorrect: They have frequencies from 300 GHz to as low as 3 kHz and corresponding wavelengths from 1 millimetre to 100 kilometres.They have a long range of wavelengths, so they can have very small wavelengths as well.Science and Technology 583 212

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