Assertion (A): A diamond sparkles more than a glass imitation cut to the same shape. Reason (R): The refractive index of diamond is less than that of glass. In the context of the above two statements, which one of the following is correct?
- ABoth A and R are true, and R is the correct explanation of A
- BBoth A and R are true, but R is not a correct explanation of A
- CA is true, but R is falseCorrect
- DA is false, but R is true
Explanation
The correct option is C because Assertion A is true while Reason R is false.
A diamond sparkles more than glass because it has a very high refractive index, approximately 2.42, compared to glass which is around 1.5. This high refractive index results in a very small critical angle for diamond. When light enters a diamond, it undergoes multiple total internal reflections before exiting, which creates the intense sparkling effect.
Reason R is false because the refractive index of diamond is significantly higher, not less, than that of glass. For an imitation to sparkle like a real diamond, it would need a higher refractive index, not a lower one.
Related questions
More UPSC Prelims practice from the same subject and topic.
- Prelims 1995GS1science-and-technology
The Nobel Prize for deciphering the language of bees was awarded to
- Prelims 1995GS1science-and-technology
Which one of the following is a mixed fertilizer?
- Prelims 1995GS1science-and-technology
The chemical used as a ‘fixer’ in photography is
- Prelims 1995GS1science-and-technology
Which one of the following can be used to confirm whether drinking water contains a gamma emitting isotope or not?
- Prelims 1995GS1science-and-technology
The normal temperature of human body on the Kelvin scale is
- Prelims 1995GS1science-and-technology
When the same note is played on a sitar and a flute, the sound produced can be distinguished from each other because of the difference in