Class 10 Science The Human Eye and the Colourful World

Class 10 Science The Human Eye and the Colourful World

 

Class 10 Science The Human Eye and the Colourful World Fill in the blanks , Multiple Choice Question [mcq] and True false .

 

Fill in the Blanks

 

1. The human eye forms an image on the light-sensitive screen called the ________. Answer: retina

2. The ability of the eye lens to adjust its focal length is called ________. Answer: accommodation

3. The minimum distance at which objects can be seen clearly without strain is called the ________. Answer: near point

4. A person with myopia can see nearby objects clearly but cannot see ________ objects distinctly. Answer: distant

5. Hypermetropia is corrected using a ________ lens. Answer: convex

6. The splitting of white light into its component colours is called ________. Answer: dispersion

7. The sequence of colours in the spectrum of white light is abbreviated as ________. Answer: VIBGYOR

8. The blue colour of the sky is due to the ________ of light. Answer: scattering

9. The twinkling of stars is caused by ________ refraction of starlight.
Answer: atmospheric

10. The far point of a normal eye is at ________. Answer: infinity

11. Presbyopia arises due to the weakening of the ________ muscles. Answer: ciliary

12. In a myopic eye, the image of a distant object is formed ________ the retina. Answer: in front of

13. The danger signal lights are red because red light is ________ scattered. Answer: least

14. A rainbow is formed due to the ________ and internal reflection of sunlight by water droplets. Answer: dispersion

15. The angle between the two lateral faces of a prism is called the ________. Answer: angle of the prism

Multiple Choice Questions (MCQs)

 

1. What is the function of the iris in the human eye?
(a) Refracts light
(b) Controls the size of the pupil
(c) Forms the image
(d) Detects light intensity
Answer: (b) Controls the size of the pupil

 

2. Which part of the eye is responsible for maximum refraction of light?
(a) Retina
(b) Cornea
(c) Lens
(d) Pupil
Answer: (b) Cornea

 

3. The near point of a normal eye is approximately:
(a) 25 cm
(b) 25 m
(c) 2.5 cm
(d) Infinity
Answer: (a) 25 cm

 

4. Myopia can be corrected using:
(a) Convex lens
(b) Concave lens
(c) Cylindrical lens
(d) Bifocal lens
Answer: (b) Concave lens

 

5. The phenomenon of light scattering by colloidal particles is called:
(a) Dispersion
(b) Tyndall effect
(c) Refraction
(d) Reflection
Answer: (b) Tyndall effect

 

6. Which colour of light is scattered the most by atmospheric particles?
(a) Red
(b) Blue
(c) Green
(d) Yellow
Answer: (b) Blue

 

7. The band of colours obtained due to dispersion of white light is called:
(a) Reflection
(b) Spectrum
(c) Scattering
(d) Refraction
Answer: (b) Spectrum

 

8. The focal length of the eye lens is adjusted by:
(a) Retina
(b) Ciliary muscles
(c) Iris
(d) Cornea
Answer: (b) Ciliary muscles

 

9. Which of the following is NOT a defect of vision?
(a) Myopia
(b) Hypermetropia
(c) Presbyopia
(d) Tyndall effect
Answer: (d) Tyndall effect

 

10. The sun appears red during sunrise and sunset due to:
(a) Dispersion
(b) Scattering
(c) Refraction
(d) Reflection
Answer: (b) Scattering

 

11. The angle of deviation in a prism depends on:
(a) Angle of incidence
(b) Angle of prism
(c) Both (a) and (b)
(d) None of these
Answer: (c) Both (a) and (b)

 

12. Which lens is used to correct hypermetropia?
(a) Concave
(b) Convex
(c) Bifocal
(d) Cylindrical
Answer: (b) Convex

 

13. The sky appears dark to astronauts because:
(a) There is no atmosphere
(b) Light is absorbed
(c) No scattering occurs
(d) Both (a) and (c)
Answer: (d) Both (a) and (c)

 

14. The far point of a myopic person is 80 cm. The power of the corrective lens required is:
(a) -1.25 D
(b) +1.25 D
(c) -0.8 D
(d) +0.8 D
Answer: (a) -1.25 D

 

15. Which phenomenon explains the advance sunrise and delayed sunset?
(a) Dispersion
(b) Scattering
(c) Atmospheric refraction
(d) Reflection
Answer: (c) Atmospheric refraction

 

True/False

 

1. The retina is a light-sensitive screen in the eye. Answer: True

2. The ciliary muscles help in changing the curvature of the eye lens. Answer: True

3. A concave lens is used to correct hypermetropia. Answer: False

4. The near point of a normal eye is 25 m. Answer: False

5. Dispersion of light occurs due to different wavelengths bending at different angles.
Answer: True

6. The blue colour of the sky is due to the reflection of light. Answer: False

7. Stars twinkle due to atmospheric refraction. Answer: True

8. Planets twinkle like stars. Answer: False

9. Presbyopia is caused by the elongation of the eyeball. Answer: False

10. The Tyndall effect is observed in true solutions. Answer: False

11. A prism can recombine the spectrum of white light. Answer: True

12. The danger signal is red because it is least scattered. Answer: True

13. The focal length of the eye lens decreases when viewing nearby objects.
Answer: True

14. The far point of a hypermetropic eye is less than infinity. Answer: False

15. A rainbow is formed in the direction of the sun. Answer: False