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Electromagnetic Waves — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsElectromagnetic Waves1 Mark
Question
Two statements are given-one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.
  1. Both A and R are true and R is the correct explanation of A.
  2. Both A and R are true but R is not the correct explanation of A.
  3. A is true but R is false.
  4. A is false and R is also false.
Assertion: X-ray astronomy is possible only from satellites orbiting the earth.
Reason: Efficiency of X-rays telescope is large as compared to any other telescope.
✓

Answer

  1. A is true but R is false.

Explanation:

The earth's atmosphere is transparent to visible tight and radio waves, but absorbs X-rays. Therefore X-rays telescope cannot be used on earth surface.

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