NCERT Science Class 10 Chapter 11 the Human Eye and the Colourful World CBSE Board Sample Problems Very Short Answer

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Question

What is the nature of image formed on the retina of the eye?

Solution

Real and inverted.

Question

State one effect produced by the scattering of light by the atmosphere?

Solution

Tyndall effect.

Question

Define power of accommodation?

Solution

The ability of the eye lens to adjust its focal length is called power of accommodation.

Question

What is the cause of dispersion of light on passing through a prism?

Solution

The refractive index of the material of a prism is different for different colours of light as different colours have different speed in the material of a prism

Question

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

Solution

The far point is infinity and near point is about 25 cm of the normal human eye.

Question

An Astronaut in space finds sky to be dark. Explain reason for this observation.

Solution

In space there is no atmosphere, so there is no scattering hence the sky appears dark/black.

Question

What is meant by scattering of light?

Solution

Scattering of light is the phenomenon due to which light gets deflected by the atoms, molecules or particles of the medium when light falls on them.

Question

Which lens is used to correct hypermetropia?

Solution

Convex lens

Question

Which phenomenon is responsible for making the path of light visible?

Solution

Tyndall effect

Question

Name the components of white light which deviates the least and the components that deviates the most while passing through a prism.

Solution

Least: Red

Most: Violet

Question

What is the smallest distance up to which an eye can see without strain?

Solution

Near point or 25 cm.

Question

A person is advised to wear spectacles with concave lens. What type of defect of vision is he suffering from?

Solution

Near-Sighted ness/Myopia

Question

Which defect of an eye can be corrected by using concave lens?

Solution

Myopia

Question

The following questions consists of two statements - Assertion (A) and Reason (R).

Answer these questions selecting the appropriate option given below:

(a) Both A and R are true and R is correct explanation of A.

(b) Both A and R are true and R is not correct explanation of A.

(d) A is false but R is true

Assertion (A): The sky looks dark and black instead of blue in outer space.

Reason (R): No atmosphere containing air in the outer space to scatter sunlight.

Solution

(a)

Question

The following questions consists of two statements - Assertion (A) and Reason (R).

Answer these questions selecting the appropriate option given below:

(a) Both A and R are true and R is correct explanation of A.

(b) Both A and R are true and R is not correct explanation of A.

(d) A is false but R is true

Assertion (A): Danger signals are made of red colour.

Reason(R). : Velocity of red light is maximum in air, so signals are visible in dark.

Solution

(C)

Question

Calculate maximum power of accommodation of a person having normal vision. (1)

Solution

For a person having normal vision, Least distance of distinct vision is d=25cm

Therefore, maximum power of accommodation,

Dioptre

(1)