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Ray Optics and Optical Instruments — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsRay Optics and Optical Instruments1 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: The images formed by total intemal reflections are brighter than those formed by mirrors or lenses.
Reason: There is no loss of intensity in total internal reflection.
✓

Answer

  1. Both A and R are true and R is the correct explanation of A.
Explanation:

In total internal reflection, 100% of incident light is reflected back into the same medium, and there is no loss of intensity, while in reflection from mirrors and refraction from lenses, th ere is always some loss of intensity. Therefore images formed by total internal reflection are much brighter than those formed by mirrors or lenses.

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