Answer the following questions:
(a) Optical and radio telescopes are built on the ground while X-ray astronomy is possible only from satellites orbiting the Earth. Why?
(b) The small ozone layer on top of the stratosphere is crucial for human survival. Why?
(a) Optical and radio telescopes are built on the ground while X-ray astronomy is possible only from satellites orbiting the Earth. Why?
(b) The small ozone layer on top of the stratosphere is crucial for human survival. Why?
Solution
(a) The Earth's atmosphere transmits visible light and radio waves, so optical and radio telescopes can be operated from the ground. However, it strongly absorbs X-rays; these never reach the ground, so X-ray astronomy must be carried out from satellites orbiting above the atmosphere.
(b) The ozone layer absorbs most of the Sun's harmful ultraviolet radiation. By preventing this high-energy UV from reaching the surface it protects living cells from damage, making it crucial for survival.
(b) The ozone layer absorbs most of the Sun's harmful ultraviolet radiation. By preventing this high-energy UV from reaching the surface it protects living cells from damage, making it crucial for survival.
CBSE Class 12 Board · 2009 · Subjective