Home
Class 10
PHYSICS
(a) For which colour of white light, is ...

(a) For which colour of white light, is the refractive index of a transparent medium (i) the least, (ii) the most ?
(b) Which colour of light travels fastest in any medium except air ?

Text Solution

AI Generated Solution

The correct Answer is:
### Step-by-Step Solution **(a)** To determine the colors of white light for which the refractive index of a transparent medium is the least and the most, we need to understand the relationship between the wavelength of light and the refractive index. 1. **Understanding Wavelength and Refractive Index:** - The refractive index (n) of a medium is inversely proportional to the wavelength (λ) of light. This means that as the wavelength increases, the refractive index decreases, and vice versa. - Mathematically, this can be expressed as: \[ n \propto \frac{1}{\lambda} \] 2. **Identifying Wavelengths of Colors:** - In the visible spectrum, red light has the longest wavelength (approximately 800 nm or 8000 Å) and violet light has the shortest wavelength (approximately 400 nm or 4000 Å). 3. **Determining the Least Refractive Index:** - Since red light has the longest wavelength, it will have the least refractive index in a transparent medium. - **Answer for part (i):** Red light has the least refractive index. 4. **Determining the Most Refractive Index:** - Conversely, violet light, having the shortest wavelength, will have the highest refractive index. - **Answer for part (ii):** Violet light has the most refractive index. **(b)** Now, we need to find out which color of light travels fastest in any medium except air. 1. **Understanding Speed of Light in a Medium:** - The speed of light (v) in a medium is directly proportional to its wavelength (λ). This means that light with a longer wavelength will travel faster in a medium compared to light with a shorter wavelength. - Mathematically, this can be expressed as: \[ v \propto \lambda \] 2. **Identifying the Color with Maximum Wavelength:** - Since red light has the longest wavelength (800 nm), it will travel the fastest in any medium except air. - **Answer for part (b):** Red light travels fastest in any medium except air. ### Final Answers - (a) (i) Red light has the least refractive index. (ii) Violet light has the most refractive index. - (b) Red light travels fastest in any medium except air.
Promotional Banner

Topper's Solved these Questions

  • REFRACTION OF LIGHT AT PLANE SURFACES

    ICSE|Exercise EXERCISE-4(A) MULTIPLE CHOICE TYPE|3 Videos
  • REFRACTION OF LIGHT AT PLANE SURFACES

    ICSE|Exercise EXERCISE-4(A) NUMERICALS|4 Videos
  • REFRACTION OF LIGHT AT PLANE SURFACES

    ICSE|Exercise EXERCISE-4(D) MULTIPLE CHOICE TYPE|3 Videos
  • REFRACTION OF LIGHT

    ICSE|Exercise DIAGRAM BASED MCQ:|5 Videos
  • REFRACTION THROUGH A LENS

    ICSE|Exercise EXERCISE-5(D) (MULTIPLE CHOICE TYPE)|2 Videos

Similar Questions

Explore conceptually related problems

Name the constituent colour of white light for which the refractive index of glass is maximum.

Which colour of the white light is deviated by a glass prism (i) the most, and (ii) the least?

Which colour of white light travels (a) fastest (b) slowest, in glass?

In the atmosphere which colour of light gets scattered the least ?

Define the term refractive index of a medium in terms of velocity of light.

How does the refractive index of a medium depend on the wavelength of light used ?

Name the colour of white light which is deviated (i) the most, and (ii) the least, on passing through a prism.

A boy uses blue colour of light to find the refractive index of glass. He then repeats the experiment using red colour of light. Will the refractive index be the same or different in the two cases? Give a reason to support your answer.

How is the refractive index of a material related to: Velocity of light in vacuum or air and the velocity of light in a given medium?

Name the constituent colour of white light for which the deviation produced by the glass prism is least

ICSE-REFRACTION OF LIGHT AT PLANE SURFACES-EXERCISE-4(A)
  1. A light ray in passing from water to a medium (a) speeds up, (b) slows...

    Text Solution

    |

  2. What do you understand by the statement the refractive index of glass ...

    Text Solution

    |

  3. A monochromatic ray of light passes from air to glass. The wavelength ...

    Text Solution

    |

  4. A boy uses blue colour of light to find the refractive index of glass....

    Text Solution

    |

  5. (a) For which colour of white light, is the refractive index of a tran...

    Text Solution

    |

  6. Name two factors on which the refractive index of a medium depends ? S...

    Text Solution

    |

  7. How does the refractive index of a medium depend on the wavelength of ...

    Text Solution

    |

  8. How does the refractive index of a medium depend on its temperature ?

    Text Solution

    |

  9. Light of a single colour is passed through a liquid having a piece of ...

    Text Solution

    |

  10. In Figure, a ray of light A incident from air suffers partial reflecti...

    Text Solution

    |

  11. The diagram alongside shows the refraction of a ray of light from air ...

    Text Solution

    |

  12. The refractive index of water with respect to air is ""(a)mu(w) and of...

    Text Solution

    |

  13. What is lateral displacement ? Draw a ray diagram showing the lateral ...

    Text Solution

    |

  14. A ray of light strikes the surface of a rectangular glass slab such th...

    Text Solution

    |

  15. In the adjacent diagram, AO is a ray of light incident on a rectangula...

    Text Solution

    |

  16. A ray of green light enters a liquid from air, as shown in figure. Ang...

    Text Solution

    |

  17. When an illuminated object is held in front of a thick plane glass mir...

    Text Solution

    |

  18. Fill in the blanks to complete the following sentence: Q: When light...

    Text Solution

    |

  19. Fill the blanks to complete the following sentence: Q: When light tr...

    Text Solution

    |

  20. Fill in the blanks to complete the following sentence: Q: The refrac...

    Text Solution

    |