A student traces the path of a ray of light through a glass prism as shown in the diagram, but leaves it incomplete and unlabelled. Redraw and complete the diagram. Also, label on it ∠ i , ∠ e , ∠ r and ∠ D .

The required diagram is given below: A triangular glass prism is a transparent object made up of glass having two triangular bases and three rectangular lateral surfaces. Here, TP - Incident ray, PO - Refracted ray, OR - Emergent ray, ∠ A - Angle of the prism, ∠ i - AngIe of incidence, ∠ r - Angle of refraction, ∠ e - Angle of emergence and ∠ D - Angle of deviation. The angle between the incident ray and normal is called the angle of incidence, represented as i . The angle between refracted ray and normal is called the angle of refraction, represented as r . The angle of the light coming out of a medium is called the angle of emergence. In refraction through a glass prism, the emergent ray is deviated from its original direction by a certain angle. The angle between the incident ray and emergent ray is called the angle of deviation.

Differentiate between a glass slab and a glass prism.

Glass slab Glass prism It has 3 parallel pairs of refracting surfaces It has 3 rectangular refracting surfaces inclined to each other bounded with 2 parallel triangular surfaces Incident ray and emergent ray are parallel to each other Incident ray and emergent ray are not parallel to each other

Draw a labelled diagram to show (i) reddish appearance of the sun at the sunrise or the sunset and (ii) white appearance of the sun at noon when it is overhead.

Scattering of light that helps us to understand the bluish colour of the sky and the reddish appearance of the Sun at the sunrise or the sunset. (i) Near the horizon, most of the blue light and shorter wavelengths are scattered away by the particles. Therefore, the light that reaches our eyes is of longer wavelengths. This gives rise to the reddish appearance of the Sun. (ii) Light from the Sun overhead would travel relatively shorter distance. At noon, the Sun appears white as only a little of the blue and violet colours are scattered.

Why is Tyndall effect shown by colloidal particles? State four instances of observing the Tyndall effect.

The phenomenon of scattering of light by the colloidal particles gives rise to Tyndall effect. Some examples of Tyndall effects are: Tyndall effect is seen when a fine beam of sunlight enters a smoke-filled room through a small hole. Thus, scattering of light makes the particles visible. Tyndall effect can also be observed when sunlight passes through a canopy of a dense forest. Here, tiny water droplets in the mist scatter light. Sky appears blue due to scattering of shorter wavelengths. Sunrise or sunset appears as red due to scattering of longer wavelengths.

E M B I B E

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR SCIENCE>Chapter 11 - The Human Eye and the Colourful World>CBSE-2023 (Outside Delhi - II)>Q 24

MEDIUM

10th CBSE

IMPORTANT

Earn 100

The phenomena of light involved in the formation of rainbow are

50% studentsanswered this correctly

Important Questions on The Human Eye and the Colourful World

EASY

10th CBSE

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR SCIENCE>Chapter 11 - The Human Eye and the Colourful World>CBSE-2018>Q 1

A student is unable to see clearly the words written on the black board placed at a distance of approximately

3 m

from him. Name the defect of vision the boy is suffering from. State the possible causes of this defect and explain the method of correcting it.

EASY

10th CBSE

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR SCIENCE>Chapter 11 - The Human Eye and the Colourful World>CBSE-2018>Q 2

Why do stars twinkle ? Explain.

EASY

10th CBSE

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR SCIENCE>Chapter 11 - The Human Eye and the Colourful World>CBSE-2018>Q 3

Write the function of cornea of human eye.

EASY

10th CBSE

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR SCIENCE>Chapter 11 - The Human Eye and the Colourful World>CBSE-2018>Q 4

Write the function of iris of human eye.

EASY

10th CBSE

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR SCIENCE>Chapter 11 - The Human Eye and the Colourful World>CBSE-2018>Q 5

Write the function of crystalline lens of human eye.

EASY

10th CBSE

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR SCIENCE>Chapter 11 - The Human Eye and the Colourful World>CBSE-2018>Q 6

Write the function of ciliary muscles of human eye.

EASY

10th CBSE

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR SCIENCE>Chapter 11 - The Human Eye and the Colourful World>CBSE-2018>Q 7

Why does the sun appear reddish early in the morning ? Will this phenomenon be observed by an astronaut on the Moon ? Give reason to justify your answer.

MEDIUM

10th CBSE

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR SCIENCE>Chapter 11 - The Human Eye and the Colourful World>CBSE-2019>Q 8

When do we consider a person to be myopic or hypermetropic? List two causes of hypermetropia. Explain using ray diagrams how the defect associated with hypermetropic eye can be corrected.

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