CBSE Class 8 Science Light Worksheet Set A

              Questions

              Very Short Answer

Q1)       What is incident ray?

Q2)       How we see various objects?

Q3)       What is angle of reflection?

Q4)       Define light?

Q5)       What is reflected ray?

             Short Answer

 Q6)       Why angle of incidence is always equal to angle of reflection?

Q7)       What makes things visible to us?

Q8)       Why ray of light is an idealisation?

Q9)       What are luminous objects?

Q10)     What do you mean by periscope?

             Long Answer

 Q11)     Write short note on lateral inversion?

Q12)     State the difference between sound and light?

Q13)     Write short note on kaleidoscope?

Q14)     Explain laws of reflection?

Q15)     State the difference between regular reflection and irregular reflection?

Question 1. When a light ray is reflected repeatedly by a set of parallel plane mirrors, the intensity of light ray decreases after some reflections. This is because of :
(a) Poor reflection from mirrors
(b) Absorption of some amount of light by mirrors
(c) Dispersion of light when the rays travel through the atmosphere
(d) Scattering of light by the mirrors
Answer: B

Question 2. The perpendicular drawn at any point on a mirror is called :
(a) Incident ray
(b) Reflected ray
(c) Normal
(d) Image
Answer: C

Question 3. Which of the following statements is true ?
(a) The angle of incidence is twice the angle of reflection
(b) The incident ray, the reflected ray and the normal drawn at the point of incidence lie in the same plane
(c) Some types of virtual images can be obtained on of the screens
(d) A convex mirror forms real image
Answer: B

Question 4. When the distance between the object and the plane mirror increases :
(a) The image remains same
(b) The size of the image will become less than the size of the object
(c) The distance between the image and the plane mirror increases
(d) The distance between the image and the plane mirror decreases
Answer: C

Question 5. In lateral inversion :
(a) Right of the object will be right side of the image
(b) Left side of the object will be left side of the image
(c) Upside of the object will be down side of the object
(d) Right side of the object will be left side of the image
Answer: D

Question 6. In a periscope, the reflecting mirrors will be :
(a) Perpendicular to each other
(b) Parallel to each other
(c) At an angle of 45°
(d) At an angle of 60°
Answer: B

Question 7. The nature of image formed on the retina of human eye is :
(a) Virtual and erect
(b) Virtual and inverted
(c) Real and erect
(d) Real and inverted
Answer: D

Question 8. The persistence of the eye is only for :
(a) 1/10 thof second
(b) 1/12 of second
(c) 1/16 of second
(d) 1/20 of second
Answer: C

Question 9. The outer layer of the eye is called :
(a) Cornea
(b) Sclerotic
(c) Choroid
(d) Retina
Answer: B

Question 10. The part which protects the human eye is called :
(a) Cornea
(b) Choroid
(c) Retina
(d) Blind spot
Answer: A

Question 11. The 'pupil' in human eye can be dilated by :
(a) Retina
(b) Choroid
(c) Optic nerve
(d) Iris
Answer: D

Question 12. Which of the following statement about human eye is not true ?
(a) The iris gives a distinct colour to the eye
(b) The yellow spot is extremely sensitive to light
(c) The space between lens and cornea is filled with ciliary muscles
(d) The optic nerves enters the eye near the blind spot
Answer: C

Question 13. Cataract is a condition of eye when :
(a) Eye sight becomes foggy
(b) Eye lens becomes cloudy
(c) There is a loss of vision
(d) All of the above
Answer: D

Question 14. Nocturnal animals like owl & bat have :
(a) Large cornea
(b) Large pupil
(c) Retina with large number of rods
(d) All of the above
Answer: D

Question 15. Night blindness occurs due to deficiency of which vitamin ?
(a) A
(b) B
(c) C
(d) D
Answer: A

Question 16. The Braille code used by blind people use dot patterns for words. How many dot patterns or characters are used for this code ?
(a) 52
(b) 63
(c) 48
(d) 26
Answer: B

Question 17. Which of the following letters will be seen without any change in a plane mirror ?
(a) S
(b) T
(c) L
(d) P
Answer: B

Question 18. An ideal mirror :
(a) Absorbs all the amount of light incident on it
(b) Refracts all the light
(c) Reflects all the light
(d) None of the above
Answer: C

Question 19. Plane mirrors are arranged at an angle to get a number of coloured images in :
(a) Periscope
(b) Kaleidoscope
(c) Telescope
(d) Thermoscope
Answer: B

Question 20. A series of fast moving still pictures can create an illusion of movement because :
(a) The eye can focus on very rapidly changing pictures
(b) Eye is quicker than the brain
(c) Eye can separate two image only when the interval of separation between them is one-tenth of a second
(d) The optical cortex can see through the rapidly moving images
Answer: C