A layer in the Earth’s atmosphere called ionosphere facilities radio communication. Why?
- The presence of ozone causes the reflection of radio waves to earth.
- Radio waves have a very long wavelength.
Which of the statements given above is/are correct?
[UPSC Civil Services Exam – 2011 Prelims]
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2
Answer: (d)
Explanation:
The Ionosphere:
- This layer is located between 80 km and 400 km and is an electrically charged layer.
- This layer is characterized by the ionization of atoms.
- Because of the electric charge, radio waves transmitted from the earth are reflected back to the earth by this layer.
- Ozone can be found in Stratosphere. Hence, statement 1 is incorrect.
- Radio waves are a type of electromagnetic (EM) radiation with wavelengths in the electromagnetic spectrum longer than infrared light.
- They have frequencies from 300 GHz to as low as 3 kHz and corresponding wavelengths from 1 millimetre to 100 kilometres. Hence, statement 2 is incorrect.
