Light – MCQs with Answers and Explanations
CBSE Class 8 Science – Chapter 16: Light (50 MCQs with Answers & Explanations)
These Multiple Choice Questions are designed strictly as per the NCERT Class 8 Science textbook,
making them ideal for CBSE Class 8 Board Examination pattern and school test preparation.
CBSE Board Examinations – Topic-wise MCQs with Answers & Explanations
This page contains a topic-wise set of 50 MCQs from Chapter 16: Light.
Each question is followed by the correct answer and a detailed, easy-to-understand explanation to help students strengthen concepts and revise effectively.
Topic 1
Basics of Light, Visibility and Shadows
Q1. Light is best described as:
Answer: (b)
Light is a form of energy that enables us to see objects. It is not a substance like matter,
but energy that travels in the form of rays or waves and carries information to our eyes.
Q2. We can see an object only when:
Answer: (c)
An object becomes visible if light coming from it (directly or after reflection) enters our eyes.
Size or colour alone cannot make it visible without light reaching the eye.
Q3. Which of the following is a luminous object?
Answer: (c)
A luminous object gives out its own light. A burning candle produces light by burning wax.
The Moon only reflects sunlight, so it is non-luminous, like a book or table.
Q4. Moon is visible at night because it:
Answer: (b)
The Moon is a non-luminous object. It shines because it reflects sunlight
falling on its surface and sends part of this light towards the Earth.
Q5. Which of the following shows that light travels in a straight line?
Answer: (b)
Sharp, well-defined shadows are formed when an opaque object blocks light.
If light could bend around objects, shadows would not be clear. This proves light travels in straight lines.
Q6. Which of the following is NOT required for the formation of a shadow?
Answer: (d)
A shadow is formed when an opaque object blocks light from a source and a screen
receives the dark patch. A transparent object allows light to pass and does not produce a clear shadow.
Q7. A clear glass pane is an example of:
Answer: (b)
A transparent object allows almost all light to pass through it. Clear glass is transparent,
so we can see objects clearly through it.
Q8. Oiled paper or frosted glass is:
Answer: (c)
Translucent materials allow light to pass partially. Objects seen through them look blurred.
Oiled paper or frosted glass are common examples.
Topic 2
Reflection of Light – Terms and Laws
Q9. The bouncing back of light from a surface is called:
Answer: (b)
When light falls on a surface and bounces back into the same medium,
the phenomenon is called reflection of light.
Q10. The ray of light that strikes a reflecting surface is called:
Answer: (c)
The ray that falls on the surface is the incident ray.
The ray that comes back is the reflected ray.
Q11. The line drawn perpendicular to a mirror at the point where light falls is called:
Answer: (b)
The normal is an imaginary line drawn at 90° to the surface at the point of incidence.
Angles of incidence and reflection are measured from this normal.
Q12. Angle of incidence is the angle between:
Answer: (c)
Angle of incidence (∠i) is measured between the incident ray and the normal at the point of incidence,
not between the ray and the mirror.
Q13. Which of the following is one of the laws of reflection?
Answer: (c)
The second law of reflection states that angle of reflection equals angle of incidence (∠r = ∠i)
for a given reflecting surface.
Q14. The first law of reflection says that:
Answer: (b)
According to the first law, the incident ray, reflected ray and normal at the point of incidence
all lie in the same plane, usually the plane of the paper or mirror surface.
Q15. A highly polished, smooth surface which reflects most of the light is called:
Answer: (b)
A mirror is a smooth, polished surface (often metal coated glass) that reflects almost all light falling on it,
obeying the laws of reflection.
Q16. Reflection of light can take place from:
Answer: (c)
Some amount of light is reflected from every surface. However, smooth surfaces (mirror, calm water)
give clear reflections, while rough ones give diffused reflection.
Q17. Which of these is used to verify laws of reflection in the lab?
Answer: (c)
A plane mirror is used with a ray box and protractor to verify that incident ray, reflected ray and normal
lie in the same plane and that ∠i = ∠r.
Topic 3
Image Formation by Plane Mirror & Lateral Inversion
Q18. The image formed by a plane mirror is:
Answer: (c)
A plane mirror forms a virtual (cannot be obtained on a screen) and erect image of an object.
It appears to be behind the mirror.
Q19. The size of the image formed in a plane mirror is:
Answer: (c)
In a plane mirror, the image is of the same size as the object. This is why dressing mirrors show us in correct proportion.
Q20. A girl is standing 2 m in front of a plane mirror. Her image will be formed:
Answer: (c)
Distance of image from a plane mirror equals distance of object in front of it.
So image is 2 m behind the mirror when the girl is 2 m in front.
Q21. The left side of an object appears as the right side in a plane mirror. This effect is called:
Answer: (b)
Lateral inversion is the left-right reversal in a mirror image. The mirror interchanges left and right sides of the object.
Q22. The word “AMBULANCE” is written in reverse on the vehicle so that drivers in front can read it correctly in:
Answer: (b)
The rear-view mirror of vehicles is a plane mirror (or nearly so). Due to lateral inversion,
the reversed word on the ambulance appears correct in this mirror, prompting drivers to give way.
Q23. Which of the following is NOT a property of an image formed by a plane mirror?
Answer: (d)
Plane mirror images are virtual, erect, same size, laterally inverted and formed as far behind the mirror as the object
is in front. They are not smaller than the object.
Q24. We cannot obtain the image formed by a plane mirror on a screen because:
Answer: (c)
A virtual image is formed when reflected rays only appear to meet behind the mirror.
Since real rays do not actually meet, the image cannot be caught on a screen.
Q25. Which of these BEST explains why plane mirrors are commonly used as dressing mirrors?
Answer: (c)
Plane mirrors produce an erect, same-sized image, giving a true idea of our appearance. Therefore, they are ideal as dressing mirrors.
Topic 4
Regular and Diffused Reflection
Q26. Regular reflection occurs from:
Answer: (b)
A plane mirror has a smooth surface, so parallel rays of light reflect in a definite direction,
giving regular reflection and clear images.
Q27. Diffused reflection takes place when light falls on:
Answer: (c)
Diffused (irregular) reflection occurs when light falls on a rough surface. Each tiny part reflects light in a different direction, scattering the rays.
Q28. In diffused reflection, the laws of reflection:
Answer: (c)
Even in diffused reflection, each small part of the rough surface obeys the laws of reflection.
Scattering happens because the surface is uneven, not because the laws fail.
Q29. Which of the following surfaces will form a clear image by reflection?
Answer: (c)
A polished steel plate behaves like a mirror and gives regular reflection, forming a clear image.
Other surfaces listed are rough and scatter light.
Q30. The main reason we can see objects around us in the daytime is that:
Answer: (c)
We see images in mirrors due to regular reflection and see other objects because they scatter sunlight in many directions
(diffused reflection). Both types help in vision.
Q31. Which statement is TRUE about diffused reflection?
Answer: (a)
Because of diffused reflection from walls, floor and objects, light spreads all around
and we can see objects from different positions in a room.
Topic 5
Multiple Reflection, Kaleidoscope and Periscope
Q32. Multiple reflection of light means:
Answer: (c)
Multiple reflection occurs when light reflects successively from two or more reflecting surfaces,
forming several images of the same object.
Q33. When the angle between two plane mirrors is decreased, the number of images seen:
Answer: (b)
As the mirrors are brought closer (angle decreases), light bounces between them more times, so the
number of images increases.
Q34. A kaleidoscope works on the principle of:
Answer: (c)
In a kaleidoscope, several plane mirrors are arranged to produce beautiful patterns by
multiple reflection of light from coloured glass pieces.
Q35. How many plane mirrors are generally used inside a simple kaleidoscope?
Answer: (c)
A simple kaleidoscope uses three plane mirrors placed in a triangular tube to produce multiple symmetric patterns.
Q36. A periscope is an instrument used to:
Answer: (b)
A periscope allows us to see objects which are not in our direct line of sight,
such as over a wall or from inside a submarine.
Q37. In a simple periscope, the mirrors are kept at an angle of:
Answer: (b)
Two plane mirrors in a periscope are kept at 45° so that light from an object reflects twice
and finally enters the observer’s eye.
Q38. Which of the following uses the idea of multiple reflection in its design?
Answer: (b)
Kaleidoscope is the device in which light is repeatedly reflected inside three plane mirrors to form many colourful patterns.
Topic 6
Sunlight, Dispersion, Spectrum and Rainbow
Q39. Sunlight appears white but actually it is:
Answer: (b)
White sunlight is a mixture of many colours. This can be shown by passing it through a glass prism to form a spectrum.
Q40. The splitting of white light into its component colours is called:
Answer: (c)
Dispersion of light is the splitting of white light into different colours, like violet, indigo, blue, green, yellow, orange and red (VIBGYOR).
Q41. The band of colours obtained on a screen when white light passes through a prism is called:
Answer: (b)
The coloured band is called a spectrum. It shows that white light is made up of several colours.
Q42. The correct order of colours in the spectrum is best remembered by:
Answer: (a)
VIBGYOR stands for Violet, Indigo, Blue, Green, Yellow, Orange, Red – the correct order of colours in sunlight’s spectrum.
Q43. Which light bends the most when white light passes through a glass prism?
Answer: (d)
Among the visible colours, violet light deviates the most inside a prism, while red deviates the least.
Q44. A rainbow in the sky is formed due to:
Answer: (c)
A rainbow forms when sunlight suffers refraction and dispersion on entering raindrops
and internal reflection inside them, then refraction again on leaving, producing a spectrum.
Q45. A rainbow is always seen in which direction with respect to the Sun?
Answer: (b)
To see a rainbow, the observer must stand with their back to the Sun.
The rainbow appears in the part of the sky opposite to the Sun because light from that direction enters the eyes.
Topic 7
Human Eye, Eye Care and Braille System
Q46. In the human eye, the image of an object is formed on the:
Answer: (c)
The retina is the light-sensitive screen at the back of the eye where a real image of the object is formed by the eye lens.
Q47. Which part of the eye controls the amount of light entering the eye?
Answer: (c)
The iris is the coloured part of the eye. It changes the size of the pupil, thereby controlling how much light enters the eye.
Q48. Why is it harmful to read in very dim light?
Answer: (b)
In dim light, the eyes have to work harder to see clearly, causing eye strain, headaches
and sometimes long-term vision problems. Reading should be done in proper light.
Q49. The Braille system is mainly used by:
Answer: (c)
The Braille system is a script of raised dots used by visually impaired persons
to read and write through touch.
Q50. Braille script is based on:
Answer: (b)
In Braille, each letter or number is represented by a particular arrangement of
raised dots in a cell. Readers feel these dots with their fingers to understand the text.
Conclusion
These 50 topic-wise MCQs from Chapter 16 – Light cover all major NCERT concepts such as
reflection, plane mirrors, multiple reflection, dispersion, rainbow, human eye and Braille.
Regular practice with the given answers and explanations will help Class 8 students revise thoroughly and score better in
CBSE Board-style examinations.