In the figure given below a narrow beam of white light is shown to pass through a triangular glass prism. After passing through the prism it produces a spectrum XY on a screen. (a) State the colour seen at X and Y. (b) Why do different colours of white light bend through different angles with respect to the incident beam of light?
In the figure given below a narrow beam of white light is shown to pass through a triangular glass prism. After passing through the prism it produces a spectrum XY on a screen. (a) State the colour seen at X and Y. (b) Why do different colours of white light bend through different angles with respect to the incident beam of light?
Official answer
a) Red, b) Violet
Marking scheme
- 1.a) Red, b) Violet
Hint
Recall the concept of dispersion and the behavior of different wavelengths of light when passing through a prism.
Quick oral answer
The colors seen at X and Y are red and violet, respectively. This is due to the dispersion of white light into its component colors as it passes through the prism. Different colors bend at different angles due to their varying wavelengths.
Common mistakes
- 1.confusing dispersion with reflection
- 2.assuming all colors bend at the same angle
Analysis and explanation
The dispersion of white light into its component colors is a result of the different refractive indices of the glass prism for different wavelengths of light. The angle of refraction depends on the wavelength of the light, with shorter wavelengths (like violet) being refracted more than longer wavelengths (like red).
Interesting facts
The dispersion of white light into its component colors was first observed by Isaac Newton in 1666.
The different colors of the visible spectrum have different wavelengths, ranging from approximately 400 nanometers (violet) to 700 nanometers (red).
Question details
Q9 of 27 questions
- Board
- CBSE
- Class
- Class 10
- Subject
- Science
- Year
- 2010
- Section
- Section A
- Marks
- 2
- Type
- Short Answer
- Chapter
- The Human Eye and the Colourful World
- Topic
- Refraction of Light through a Prism
- Bloom's level
- Comprehension
- Syllabus topic
- Refraction of Light
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Frequently asked questions
How many marks does this question carry in CBSE Class 10 Science 2010?
This question carries 2 marks in the CBSE Class 10 Science 2010 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 "Refraction of Light through a Prism" from CBSE Class 10 Science.
What type of question is this in the CBSE Class 10 Science 2010 paper?
This is a Short Answer question from Section A in the CBSE Class 10 Science 2010 paper.