VSAQ for Human Eye and the Colourful World Class 10 Science NCERT
Important Questions1
Define power of accommodation.
OR
What is meant by power of accommodation of the eye?
Answer
The ability of the eye lens to focus clearly on the retina by adjusting its focal length is known as the power of accommodation.
VSAQ
2
What is the purpose of human eye?
Answer
It enables us to see and perceive the objects in our vicinity.
VSAQ
3
State one function of iris in human eye.
Answer
Function of Iris: It controls the size of the pupil.
VSAQ
4
Name the part of the human eye that helps in changing the focal length of the eye lens.
Answer
Ciliary muscles.
VSAQ
5
What is the range of vision of a normal human eye?
Answer
25 cm to infinity.
VSAQ
6
What is the function of pupil in human eye?
Answer
The pupil helps to control the amount of light entering the eye.
VSAQ
7
Name the part of the eye:
(i) That controls the amount of light entering into the eye.
(ii) That has real, inverted image of the object formed on it.
Answer
(i) Pupil,
(ii) Retina.
VSAQ
8
What is the nature of the image formed on the retina ?
Answer
Real, inverted and diminished in size.
VSAQ
9
A person is advised to wear spectacles with convex lenses. State the defect of vision he is suffering from
Answer
The person is suffering from hypermetropia.
VSAQ
10
What is meant by dispersion of light?
Answer
The splitting of light into its component colours is called dispersion of light.
VSAQ
11
What is tyndall effect?
Answer
The scattering of light by colloidal solution is called tyndall effect.
VSAQ
12
Name the type of particles which acts as a prism in the formation of rainbow in the sky.
Answer
Water droplets present in the atmosphere.
VSAQ
13
Which coloured component bends the least during the dispersion of white light through prism?
Answer
Red.
VSAQ
14
Which colour of white light suffers
(i) least deviation and
(ii) maximum deviation when a beam of white light passes through a glass prism?
OR
Name the component of white light that deviates the least and the most while passing through a prism.
Answer
(i) Least deviation-Red.
(ii) Maximum deviation - Violet.
VSAQ
15
On which factor does the colour of the scattered white light depend ?
Answer
Size of the particles of the medium through which it is passing.
VSAQ
16
The sky appears dark to passengers flying at a very high altitude. Why?
Answer
Due to lack of atmosphere, scattering is not prominent.
VSAQ
17
The sky appears dark instead of blue to an astronaut State its reason.
Answer
The sky appears dark to the astronauts scattering does not take place at very high attitude due to the absence of atmosphere.
VSAQ
18
What is the cause of dispersion of light on passing through a prism.
Answer
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. Also, prism has non-parallel surfaces.
VSAQ