Class 10 Science Chapter 11 MCQ with Answers for 2020-2021
| Class: 10 | Science |
| Chapter: 11 | Human Eye and Colourful World |
| Contents: | MCQ Online Tests with Explanation and Answers |
Class 10 Science Chapter 11 MCQ Online Test for 2020-21
Class 10 Science Chapter 11 MCQ Online tests with solutions and explanation are given below. All the questions are important for exams. After completing Chapter 11 from NCERT Textbook, these questions are helpful for the preparation of exams in less time.
Q1
Ruby is completed her science chapter where she wrote some statements. She wants to know whether the statements are correct or not? Ruby wants to take help from you:
[A]. The retina is a delicate membrane having a large number of light sensitive cells called “rods” and “cones”.
[B]. Blind spot is a small area of the retina insensitive to light where the optic nerve leaves the eye.
[C]. The space between cornea and eye lens is filled with a watery liquid called “vitreous humor”.
[D]. The retina is behind the eye-lens and at the back part of the eye.
Answer: Option C
Explanation:the space between cornea and eye lens is filled with a watery liquid called “aqueous humor”. And the space between eye lens and retina is filled with transparent jelly like substance called vitreous humour which supports the back of the eye.
Q2
Which of the following phenomena of light are involved in the formation of a rainbow?
[A]. Reflection, refraction and dispersion.
[B]. Refraction, dispersion and total internal reflection.
[C]. Refraction, dispersion and internal reflection
[D]. Dispersion, scattering and total internal reflection
Answer: Option C
Explanation:Rainbow is caused by dispersion, refraction and internal reflection of sunlight by tiny water droplets, present in the atmosphere and always formed in a direction opposite to that of the sun. The water droplets act like a small prism. They refract and disperse the incident sunlight, then reflect it internally and finally refract it again when it comes out of the raindrop.
Q3
Which of the following is not caused by the atmospheric refraction of light?
[A]. Twinkling of stars at night
[B]. Sun appearing higher in the sky than it actually is
[C]. Sun becoming visible two minutes before actual sunrise
[D]. Sun appearing red at sunset
Answer: Option D
Explanation:The sun appears red at sunset not because of the atmospheric refraction of light but because of the scattering effect of light.
Q4
Read the following sentences carefully, and choose the incorrect one:
[A]. The rays of light coming from a distant object are parallel to one another when the reach the eye.
[B]. The rays of light coming from a nearby object are diverging when they reach the eye.
[C]. An eye can focus the image of the distant objects as well as the nearby objects on its retina by changing the focal length of its lens.
[D]. When the eye is looking at a distant object, the eye is said to be accommodate.
Answer: Option D
Explanation:When the eye is looking at a distant object, the eye is said to be unaccommodated because it is the relaxed state of the eye.
Q5
Which of the following statement is correct regarding the propagation of light of different colours of light in air
[A]. Red light moves fastest
[B]. Blue light moves faster than green light
[C]. All the colours of the white light move with the same speed
[D]. Yellow lights moves with the mean speed as that of the red and the violet light.
Answer: Option C
Explanation: the propagation of light of different colours of white light in air or vacuum move with the same speed but different wavelengths and frequencies.
Q6
The danger signals installed at the top of tall buildings are red in colour. This can be easily seen from the distance because among all the other colours, the red light:
[A]. Is scattered the most by smoke or fog
[B]. is scattered the least by smoke or fog
[C]. Is absorbed the most by smoke or fog
[D]. Moves fastest in air
Answer: Option B
Explanation:The danger signals installed at the top of tall buildings are red in colour because among all other colours, red colour is scattered the least by smoke of fog. This is primarily because wavelength of red colour is the largest. Thus, it can be easily seen from a distance.
Q7
A man driving a car can read a distant road sign clearly but finds difficulty in reading the odometer on the dashboard of the car. Which of the following statement is correct about this man?
[A]. The near point of his eyes has receded away.
[B]. The near point of his eyes has come closer to him.
[C]. The far point of his eyes has receded away.
[D]. The far point of his eyes has come closer to him.
Answer: Option A
Explanation:If a man driving a car can see a distant road sign distinctly but cannot read the odometer on the dashboard of the car clearly, it suggests that the near point of his eyes has receded.
Q8
The focal length of the eye lens increases when eye muscles
[A]. Are relaxed and lens become thinner
[B]
[C]
[D]
[B]. Contract and lens becomes thicker
[C]. Are relaxed and lens becomes thicker
[D]. Contract and lens becomes thinner
Answer: Option A
Explanation:The focal length of the eye lens increases when eye muscles relaxed and becomes thinner. The sharp image of the distant object is formed at the retina. This enables us to focus accurately on distant objects.
Q9
The human eye possesses the power of accommodation. This is the power to:
[A]. Alter the diameter of the pupil as the intensity of light changes
[B]. Distinguish between lights of different colours
[C]. Focus on objects at different distances
[D]. Decide which of the two objects is closer.
Answer: Option C
Explanation:The human eye possesses the power of accommodation to focus on objects at different distances.
Q10
How does the eye change in order to focus on near or distant objects?
[A]. The lens moves in or out
[B]. The retina moves in or out
[C]. The lens becomes thicker or thinner
[D]. The pupil gets larger or smaller
Answer: Option C
Explanation:The eye lens becomes thicker to focus on nearby objects and thinner to focus on distant objects.
What is the function of Iris?
Iris is a dark muscular diaphragm that controls the size of the pupil.
What is meant by accommodation of eye?
The ability of the eye lens to adjust its focal length is called accommodation.
Why do stars twinkle?
The twinkling of a star is due to atmospheric refraction of starlight. The starlight, on entering the earth’s atmosphere, undergoes refraction continuously before it reaches the earth.This makes continuously change in star’s position and we see the twinkling of stars.
Why does sky apear blue in colour?
The molecules of air and other fine particles in the atmosphere have size smaller than the wavelength of visible light. These are more effective in scattering light of shorter wavelengths at the blue end than light of longer wavelengths at the red end. When sunlight passes through the atmosphere, the fine particles in air scatter the blue colour (shorter wavelengths) more strongly than red. The scattered blue light enters our eyes and we see blue sky.
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