The colour of light for which the refractive index of glass is minimum, is :
The colour of light for which the refractive index of glass is minimum, is :
Options
The correct option is A.
Marking Scheme
- 11 mark
Hint
Think about which colour of light bends the least when passing through a glass prism, as the refractive index is directly related to the amount of bending.
Quick Oral Answer
The refractive index of glass is minimum for red light because red light travels fastest in glass and bends the least when passing through a prism.
Analysis & Explanation
According to the NCERT textbook (Section 10.4), different colours of light bend through different angles with respect to the incident ray as they pass through a prism. The text states: 'The red light bends the least while the violet the most.'
The angle of bending (deviation) of a light ray in a medium is directly proportional to the refractive index of that medium for that specific colour. Since red light bends the least, the refractive index of glass is minimum for red light. Conversely, since violet light bends the most, the refractive index of glass is maximum for violet light.
- Option A is correct because red light has the longest wavelength in the visible spectrum and experiences the least refraction (minimum refractive index) in glass.
- Options B, C, and D are incorrect because yellow, green, and violet lights bend more than red light, meaning the refractive index of glass for these colours is higher than that for red light.
Common Mistakes
- 1Confusing minimum refractive index with maximum bending, leading to choosing Violet instead of Red.
Interesting Facts
Isaac Newton was the first to use a glass prism to obtain the spectrum of sunlight, proving that white light consists of seven constituent colours.
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Frequently Asked Questions
How many marks does this question carry in CBSE Class 10 Science 2024?
This question carries 1 mark in the CBSE Class 10 Science 2024 examination.
Which chapter does this question come from in Science?
This question is from the chapter "The Human Eye and the Colourful World" in the CBSE Class 10 Science syllabus.
What topic does this question cover in Science?
This question covers the topic "Dispersion of White Light by a Glass Prism" from CBSE Class 10 Science.
What type of question is this in the CBSE Class 10 Science 2024 paper?
This is a MCQ question from Section A in the CBSE Class 10 Science 2024 paper.