<p><span style="background-color:transparent; color:rgb(0, 0, 0); font-family:arial; font-size:11pt">Why do stars twinkle?</span></p>

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Why do stars twinkle? | Class 10 Science Chapter The Human Eye and the Colourful World, The Human Eye and the Colourful World NCERT Solutions

Welcome to the NCERT Solutions for Class 10 Science - Chapter The Human Eye and the Colourful World. This page offers a step-by-step solution to the specific question from Exercise 2, Question 10: . With detailed answers and explanations for each chapter, students can strengthen their understanding and prepare confidently for exams. Ideal for CBSE and other board students, this resource will simplify your study experience.

Question 10:

Why do stars twinkle?

Answer:

Stars twinkling appears due to the atmospheric refraction of the starlight. When the starlight enters on the earth surface, refraction undergoes continuously with gradually changes in refractive index before it reaches the earth surface. The atmospheric physical condition changes, i.e, do not remain stationary, the apparent position (when star is slightly different from its original position) of the stars are also not stationary. When the refractive index changes continuously due to which path of the light rays from the stars keeps on changing the path continuously. As the path of rays of light that comes from the stars, goes on varying slightly. The apparent position of the stars fluctuates and the starlight enters the eye- sometimes the star may appear brighter, and sometime this effect is known as the twinkling effect.

Other Questions of Chapter The Human Eye and the Colourful World

Why does the sky appear dark instead of blue to an astronaut?

Why does the Sun appear reddish early in the morning?

What happens to the image distance in the eye when we increase the distance of an object from the eye?

Why is a normal eye not able to see clearly the objects placed closer than 25 cm?

Make a diagram to show how hypermetropia is corrected. The near point of a hypermetropic eye is 1 m. What is the power of the lens required to correct this defect? Assume that the near point of the normal eye is 25 cm.

The far point of a myopic person is 80 cm in front of the eye. What is the nature and power of the lens required to correct the problem?

The change in focal length of an eye lens is caused by the action of the

(a) pupil. (b) retina.
(c) ciliary muscles. (d) iris.

The human eye can focus on objects at different distances by adjusting the focal length of the eye lens. This is due to

(a) presbyopia.
(b) accommodation.
(c) near-sightedness.
(d) far-sightedness.

A student has difficulty reading the blackboard while sitting in the last row. What could be the defect the child is suffering from? How can it be corrected?

A person with a myopic eye cannot see objects beyond 1.2 m distinctly. What should be the type of the corrective lens used to restore proper vision?

Popular questions of class 10 Science

When a 12 V battery is connected across an unknown resistor, there is a current of 2.5 mA in the circuit. Find the value of the resistance of the resistor.

Outline a project which aims to find the dominant coat colour in dogs.

Draw the structure for the following compounds.

(i) Ethanoic acid (ii) Bromopentane*
(iii) Butanone (iv) Hexanal.

*Are structural isomers possible for bromopentane?

A hot plate of an electric oven connected to a 220 V line has two resistance coils A and B, each of 24 Ω resistance, which may be used separately, in series, or in parallel. What are the currents in the three cases?

How is the sex of the child determined in human beings?

(a) What property do all elements in the same column of the Periodic Table as boron have in common?
(b) What property do all elements in the same column of the Periodic Table as fluorine have in common?

Calculate the number of electrons constituting one coulomb of charge.

A man with blood group A marries a woman with blood group O and their daughter has blood group O. Is this information enough to tell you which of the traits – blood group A or O – is dominant? Why or why not?

What is an homologous series? Explain with an example.

Why is variation beneficial to the species but not necessarily for the individual?

Recently Viewed Questions of Class 10 Science

Give any two ways in which non-biodegradable substances would affect the environment.

Will the impact of removing all the organisms in a trophic level be different for different trophic levels? Can the organisms of any trophic level be removed without causing any damage to the ecosystem?

On the basis of the issues raised in this chapter, what changes would you incorporate in your lifestyle in a move towards a sustainable use of our resources?

Where do plants get each of the raw materials required for photosynthesis?

How can you as an individual contribute or make a difference to the management of (a) forests and wildlife, (b) water resources and (c) coal and petroleum?

Can you suggest some changes in your school which would make it environment-friendly?

Answer the following :
(a) Which hormone is responsible for the changes noticed in females at puberty?
(b) Dwarfism results due to deficiency of which hormone?
(c) Blood sugar level rises due to deficiency of which hormone?
(d) Iodine is necessary for the synthesis of which hormone?

What changes are observed in the uterus subsequent to implantation of young embryo?

If you could use any source of energy for heating your food, which one would you use and why?

A Mendelian experiment consisted of breeding tall pea plants bearing violet flowers with short pea plants bearing white flowers. The progeny all bore violet flowers, but almost half of them were short. This suggests that the genetic make-up of the tall parent can be depicted as

(a) TTWW
(b) TTww
(c) TtWW
(d) TtWw

Study Tips for Answering NCERT Questions:

NCERT questions are designed to test your understanding of the concepts and theories discussed in the chapter. Here are some tips to help you answer NCERT questions effectively:

Read the question carefully and focus on the core concept being asked.
Reference examples and data from the chapter when answering questions about The Human Eye and the Colourful World.
Review previous year question papers to get an idea of how such questions may be framed in exams.
Practice answering questions within the time limit to improve your speed and accuracy.
Discuss your answers with your teachers or peers to get feedback and improve your understanding.

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