Question

Class 8 Science MCQ Questions of Light with Answers?

Answer 1

Class 8 Science MCQ Questions of Light with Answers had been organized primarily based totally on the most recent examination pattern. We have supplied Light Class 8 Science MCQ Questions with Answers to help college students is aware of the concept alright. Solve and practice higher-order thinking questions from Class 8 Science MCQ Questions of light with Answers. 

Light is an electromagnetic wave inside a specific part of the spectrum. The college students will examine the diverse residences of light and their sources. Along the aspect these, they’re going to be added to the laws of mirrored image and the manner a person’s eye works or how does an eye constantly see images. Solve the given below MCQ Questions for class 8 Science with Answers to check your practice level.

Practice Class 8 Science MCQ Questions chapter-wise

1. A smooth shining surface, which rebounds the light back in the same or in a different direction, is called

(a) a mirror
(b) a lens
(c) reflection of light
(d) point of incidence

2. Beam of light striking the reflecting surface is called

(a) reflecting ray
(b) incident ray
(c) refracted ray
(d) normal ray

3. Band of seven colors is called

(a) VIBGYOR
(b) spectrum
(c) dispersion
(d) reflection

4. Front bulged part of the eyeball is called

(a) cornea
(b) choroid
(c) pupil
(d) retina

5. Which one of the following statements is correct regarding rods and cones in the human eye?

(a) Cones are sensitive to dim light
(b) Cones are sensitive to bright light
(c) Rods are sensitive to bright light
(d) Rods can sense colour

6. In the case of reflection of light, the angle of incidence (i) and the angle of reflection (r) are related as

(a) i = r
(b) i < r
(c) i > r
(d) no definite relation

7. Name the type of mirror used as a back view mirror.

(a) Plane mirror
(b) Concave mirror
(c) Convex mirror
(d) Any of these

8. Visually impaired people can read and write using

(a) electronic writer
(b) digital pens
(c) braille system
(d) hearing aids

9. The image formed by a convex lens in a simple microscope is ...... erect and ...........

(a) Virtual, magnified
(b) Real, magnified
(c) Virtual, diminished
(d) Real, diminished

10. What is the angle of incidence of a ray if the reflected ray is at an angle of 90° to the incident ray?

(a) 60°
(b) 45°
(c) 90°
(d) 180°

11. The splitting of white light into its seven constituent colours is called

(a) refraction
(b) dispersion
(c) deviation
(d) reflection

12. The defect due to which a person is not able to see the distant objects clearly:

(a) Myopia
(b) Hypermetropia
(c) Cornea
(d) Cataract

13. The amount of light entering the eye is controlled by

(a) eye lens
(b) cornea
(c) iris
(d) ciliary muscle

14. Myopia can be corrected by using a

(a) concave lens
(b) convex lens
(c) opaque lens
(d) microlens

15. Light enters the eye through

(a) eye lens
(b) pupil
(c) cornea
(d) retina

16. If the angle of incidence of light falling on a plane mirror is 30°, what will be the angle of reflection?

(a) 90°
(b) 60°
(c) 30°
(d) 0°

17. Rainbow is a natural phenomenon showing

(a) Refraction
(b) Deflection
(c) Dispersion
(d) Diversion

18. In the retina of the eye, the area having no sensory cells is called

(a) iris
(b) Blind spot
(c) cornea
(d) Dark spot

19. Which of the following is not a luminous object?

(a) sun
(b) candle
(c) moon
(d) Tube light

20. In our eye _______ cells can sense colour

(a) Rod
(b) Cone
(c) Both rod and cone
(d) Neither rod nor cone

21. An owl can see clearly at night but not day time because it has

(a) More rods and a few cones
(b) Less rod and more cones
(c) More rods and more cone
(d) Less rods and less cones

22. The backside of a plane mirror contains

(a) gold coating
(b) silver coating
(c) aluminum coating
(d) copper coating

23. The reflection of light from a smooth surface is called

(a) diffused reflection
(b) regular reflection
(c) dispersion
(d) spectrum

24. If you hold a pen in your right hand and stand in front of the mirror, the pen will be in the left hand in the image. This phenomenon is called

(a) lateral inversion
(b) diffraction
(c) reflection
(d) inversion

25. The disease of eye in which crystalline lens becomes hazy or even opaque due to development of membrane over it is :

(a) Myopia
(b) Cataract
(c) Hypermetropia
(d) Presbyopia

Answer 2

1. Answer: (a) a mirror

Explanation: A smooth shining surface, which rebounds the light back in the same or in a different direction, is called a mirror

2. Answer: (b) incident ray

Explanation: The light striking the reflecting surface is called the incident ray.

3. Answer: (b) spectrum

Explanation: A prism separates white light into a group of seven colors called a spectrum. These seven colors are always in the same order. The colors of the spectrum are red, orange, yellow, green, blue, indigo, and violet.

4. Answer: (a) cornea

Explanation: The outer layer of the eyeball is a tough, white, opaque membrane called the sclera (the white of the eye). The slight bulge in the sclera at the front of the eye is a clear, thin, dome-shaped tissue called the cornea.

5. Answer: (b) Cones are sensitive to bright light

Explanation: The retina is the back part of the eye that contains the cells that respond to light. These specialized cells are called photoreceptors. There are 2 types of photoreceptors in the retina: rods and cones. The rods are most sensitive to light intensity changes. They contain only one type of light-sensitive pigment. Rods are not good for color vision. In a dim room, however, we use mainly our rods, but we are color blind. Rods are more numerous than cones in the periphery of the retina. There are about 120 million rods in the human retina.
The cones are less sensitive to light. However, cones are more sensitive to one of three different colors (green, red, or blue). Signals from the cones are sent to the brain which then translates these messages into the perception of color. Cones, however, work only in bright light. 

6. Answer: (a) i = r

Explanation: The angle of incidence is the angle between this normal and the incident ray; the angle of reflection is the angle between this normal and the reflected ray. According to the law of reflection, the angle of incidence equals the angle of reflection.

7. Answer: (c) Convex mirror

Explanation: A convex mirror is preferred as a rear-view mirror in cars and vehicles as it gives a wider field of view, that helps the driver to see most of the traffic behind him. Convex mirrors always form an erect, virtual, and diminished image of the objects placed in front of it.

8. Answer: (c) braille system

Explanation: Braille system is specifically used by visually impaired and challenged person who doesn't have eyesight.

9. Answer: (a) Virtual, magnified

Explanation: The image formed by a convex lens in a simple microscope is virtual and magnified.

10. Answer: (b) 45°

Explanation: If the reflected ray is at the angle of 90 degrees to the incident ray, then the angle of incidence is 45 degrees. According to the law of reflection, the angle of incidence is equal to the angle of reflection. 90/2 = 45 degrees.

11. Answer: (b) dispersion

Explanation: Dispersion of white light is explained as the splitting up of white light into seven constituent colours when it gets passed through the prism. This separation of white light into its constituent seven colours is called dispersion of light. 

12. Answer: (a) Myopia

Explanation: Myopia is an eye disorder. In myopia, the eyeball is too long for the normal focusing power of the eye. As a result, images of distant objects appear blurred.

13. Answer: (c) iris

Explanation: Iris is the small circular opening of the human eye's lens that can change its diameter in order to control the amount of light entering the eye's internal portion.

14. Answer: (a) concave lens

Explanation: Thus the concave lens is used to correct myopia and the convex lens is used to correct hypermetropia.

15. Answer: (c) cornea

Explanation: Light enters our eye through the cornea, the clear, curved layer in front of the iris and pupil.

16. Answer: (c) 30°

Explanation: The incident ray will have an angle of reflection of 30 degrees (made with a surface normal to the mirror surface). The reflected ray will make an angle of 60 degrees (90 - 30 degrees) with the mirror surface.

17. Answer: (c) Dispersion

Explanation: Rainbows are formed by the dispersion of light & reflection (not total internal reflection) from drops of water.

18. Answer: (b) Blind spot

Explanation: There are no sensory cells at the junction of the optic nerve and the retina, so no vision is possible at that point. It's called a blind spot.

19. Answer: (c) moon

Explanation: Moon is not a luminous object. A luminous object is one that has its own light. While a non-luminous object reflects the light from a luminous body and thus shines.

20. Answer: (b) Cone

Explanation: Scientists have known for decades that some cells known as cones detect color. They are part of the retina inside the back of the eye. Cone cells can sense red, green, or blue light

21. Answer: (a) More rods and few cones

Explanation: An owl is a night bird with fewer cones and more rods in the retina, therefore, it can see well at night but not during the day. ... Moreover, an owl has a large cornea and a large pupil to allow more light to enter its eye during the night. Hence, vision is more clear during the night in an owl.

22. Answer: (b) silver coating

Explanation: A plane mirror is made using some highly reflecting and polished surface such as a silver or aluminum surface in a process called silvering. After silvering, a thin layer of red lead oxide is applied at the back of the mirror.

23. Answer: (b) regular reflection

Explanation: Regular reflection is a reflection in which a parallel beam of incident rays is reflected as a parallel beam. Reflection from a smooth surface is regular reflection.

24. Answer: (a) lateral inversion

Explanation: Lateral inversion is the reversal of mirror image where the right side of the object appears on the left side behind the mirror.

25. Answer: (b) Cataract

Explanation: A cataract is a cloudy area in the lens of the eye that leads to a decrease in vision. Cataracts often develop slowly and can affect one or both eyes.

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