Class 10 Science - Chapter The Human Eye and the Colourful World NCERT Solutions | Make a diagram to show how hypermetropia

What is the far point and near point of the human eye with normal vision?

Explain why the planets do not twinkle.

Why do stars twinkle?

What is meant by power of accommodation of the eye?

The human eye forms the image of an object at its

(a) cornea.          (b) iris.          (c) pupil.          (d) retina.

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?

The least distance of distinct vision for a young adult with normal vision is about

(a) 25 m.          (b) 2.5 cm.          (c) 25 cm.          (d) 2.5 m.

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?

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.

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

Did Döbereiner’s triads also exist in the columns of Newlands’ Octaves? Compare and find out.

What is a good source of energy?

Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?

What are trophic levels? Give an example of a food chain and state the different trophic levels in it.

What changes can you make in your habits to become more environment-friendly?

What is the difference between a reflex action and walking?

What is the importance of DNA copying in reproduction?

If a trait A exists in 10% of a population of an asexually reproducing species and a trait B exists in 60% of the same population, which trait is likely to have arisen earlier?

Why should a magnesium ribbon be cleared before burning in air?

Define the principal focus of a concave mirror.

Oil and fat containing food items are flushed with nitrogen. Why?

Why is sodium kept immersed in kerosene oil?

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?

What is the need for a system of control and coordination in an organism?

How many structural isomers can you draw for pentane?

Explain different ways to induce current in a coil.

An object 5 cm in length is held 25 cm away from a converging lens of focal length 10 cm. Draw the ray diagram and find the position, size and the nature of the image formed.

Will geographical isolation be a major factor in the speciation of an organism that reproduces asexually? Why or why not?

How would you distinguish experimentally between an alcohol and a carboxylic acid?

How does the electronic configuration of an atom relate to its position in the Modern Periodic Table?