Students can practice the best Class 8 Science MCQ and Light Mirrors and Lenses Class 8 Science Curiosity Chapter 10 MCQ Online Test with Answers for exam preparation.
Class 8 Science Chapter 10 Light Mirrors and Lenses MCQ
Light Mirrors and Lenses MCQ
Class 8 Science Chapter 10 MCQ Online Test
Question 1.
Which of the following mirrors can form both real and virtual images?
(a) Plane mirror
(b) Convex mirror
(c) Concave mirror
(d) All of the above
Answer:
(c) Concave mirror
Question 2.
Rahul placed a lens on a table. He noticed that when he looked through it, object appeared smaller. Which types of lens is it? (Competency Based Que.)
(a) Convex lens
(b) Concave lens
(c) Plane glass
(d) Magnifying glass
Answer:
(b) Concave lens
Question 3.
A tiny mirror M is fixed on a piece of cardboard placed on a table. The cardboad is Illuminated by light from a bulb is shown in figure as A B, C and D. In which position, mirror will be visible?
(Competency Based Que.)
(a) A
(b) C
(c) B
(d) D
Answer:
(a) A
Question 4.
Two mirrors A and B are placed at right angles to each othe as shown in figure.
A ray of light incident on mirror A at an angle of 20° falls on mirror S after reflection. The angle of reflection for the ray reflected from mirror B would be
(a) 25°
(b) 70°
(c) 50°
(d) 115°
Answer:
(b) 70°
Question 5.
A small hole Pis made in a piece of cardboard. The hole is Illuminated by a torch as shown in figure. The pencil of light coming out of the hole falls on a mirror.
At which point should the eye be placed so that the hole can be seen ? (Competency Based Que.)
(a) A
(b) B
(c) C
(d) D
Answer:
(a) A
Question 6.
Light is falling on surfaces S1, S2, S3 as shown in figure.
Surface on which the angles of incidence is equal to the angle of reflection is/are
(a) Only S2
(b) S1 and S2
(c) S2 and S3
(d) All of three surfaces
Answer:
(d) All of three surfaces
Question 7.
In a cinema projector, which optical components is not used?
(a) Concave mirror
(b) Convex lens
(c) Plane mirror
(d) Convex mirror
Answer:
(b) Convex lens
Question 8.
If you stand in front of a plane mirror and search your right cheek, your image
(a) scratches its right cheek
(b) scratches its left cheek
(c) scratches both cheeks
(d) does not scratch at all
Answer:
(b) scratches its left cheek
Question 9.
You are using a lens that helps you read very small letters by making them look bigger. Which lens are you likely using?
(a) Concave lens
(b) Convex lens
(c) Cylindrical lens
(d) Plane glass piece
Answer:
(b) Convex lens
Question 10.
Which of the following statements is true for a concave lens?
(a) It always forms a real image.
(b) It is thicker at the edges than at the centre
(c) It is used in telescopes.
(d) It converges light rays
Answer:
(b) It is thicker at the edges than at the centre
Question 11.
Doctors use a special lens to see inside your eyes during eye checkups. Which lens do they use?
(a) Convex lens
(b) Concave lens
(c) Plane mirror
(d) Prism
Answer:
(a) Convex lens
Question 12.
A torchlight gives a strong, focused beam when a lens is placed in front, which lens is being used and what is its function? (Competency Based Que.)
(a) Convex lens — it converges light
(b) Concave lens — it scatters light
(c) Plane glass — no effect on light
(d) Mirror — reflects light only
Answer:
(a) Convex lens — it converges light
Question 13.
In a plane mirror, laterally inverted means
(a) the top appears at the bottom
(b) left and right are reversed
(c) the image is smaller than the object
(d) the image appears behind the mirror
Answer:
(b) left and right are reversed
Question 14.
Which of these uses a concave mirror for that reason?
(a) Car rear view mirror
(b) Solar cooker
(c) Torch
(d) Makeup mirror
Answer:
(b) Solar cooker
Question 15.
The angle between the incident ray and the normal is called
(a) angle of refraction
(b) angle of deviation
(c) angle of incidence
(d) angle of reflection
Answer:
(c) angle of incidence
Question 16.
Which of these statements is false for images formed by a concave lens?
(a) The image is always virtual.
(b) The image size is always smaller than the object.
(c) The image is always erect.
(d) The image can be projected onto a screen.
Answer:
(d) The image can be projected onto a screen.
Light Mirrors and Lenses Class 8 Assertion Reason Questions
The following questions consist of two statements. Assertion (A) and Reason (R). Answer the following questions by selecting the appropriate option given below
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is not the correct explanation of A
(c) A is true but R is false
(d) A is false but R is true
Question 1.
Assertion (A) The image formed by a plane mirror is always virtual and erect.
Reason (R) The light rays actually meet after reflection. (Competency Based Que.)
Answer:
(c) A is true but R is false
Question 2.
Assertion (A) The angle of incidence is always equal to the angle of reflection.
Reason (R) Reflection of light from a smooth surface follows regular reflection.
Answer:
(b) Both A and R are true but R is not the correct explanation of A
Question 3.
Assertion (A) In a plane mirror, the image appears laterally inverted.
Reason (R)The laws of reflection are not followed in a plane mirror.
Answer:
(c) A is true but R is false
Question 4.
Assertion (A) The word “AMBULANCE” is written laterally inverted on the front of an ambulance.
Reason (R) Drivers in front can read it correctly in their rear-view mirrors.
Answer:
(a) Both A and R are true and R is the correct explanation of A
Question 5.
Assertion (A) Plane mirrors form laterally inverted images.
Reason (R) Light reflects back from a smooth surface at random angles.
Answer:
(c) A is true but R is false
Question 6.
Assertion (A) A convex lens always forms a virtual image. Reason (R) Convex lens diverges light rays.
Answer:
(d) A is false but R is true
Light Mirrors and Lenses Class 8 Case Based MCQ Questions
Question 1.
A beam of light is reflected from a mirror placed on a sheet of paper. When the paper is bent, the reflected beam disappears but reappears when the paper is flat again. This shows that the incident ray, normal, and reflected ray must lie in the same plane. (Competency Based Que.)
(i) What happens to the reflected beam when the paper is bent?
(a) It becomes brighter
(b) It disappears
(c) It bends further
(d) It splits into two beams
Answer:
(b) It disappears
(ii) Why does the reflected beam disappear when the sheet is bent?
(a) The mirror absorbs the light
(b) The incident ray is blocked
(c) The new plane breaks the alignment
(d) The mirror is removed
Answer:
(c) The new plane breaks the alignment
(iii) What does this activity prove?
(a) Angle of incidence is zero
(b) Light bends around corners
(c) Incident ray, normal and reflected ray lie in the same plane
(d) Light speed decreases
Answer:
(c) Incident ray, normal and reflected ray lie in the same plane
(iv) In the second diagram, even if the incident rays are different, what remains the same?
(a) Normal direction changes
(b) Reflected ray is random
(c) All rays lie in the same plane
(d) Mirror is moved
Answer
(c) All rays lie in the same plane
Question 2.
Figure shows three different situations of an incident light ray falling on a plane mirror.
(i) In case (a), what is the angle of incidence?
(a) 0°
(b) 90°
(c) 45°
(d) 180°
Answer:
(a) 0°
(ii) In case (a), what will happen to the incident ray?
(a) It gets reflected back normally.
(b) It passes through the mirror.
(c) It does not strike the mirror at all.
(d) It bends towards the mirror.
Answer:
(a) It gets reflected back normally.
(iii) In case (b), the angle of incidence is equal to
(a) The angle between the incident ray and the mirror surface
(b) The angle between the incident ray and the normal
(c) Always 0°
(d) Always 90°
Answer:
(b) The angle between the incident ray and the normal
(iv) In case (c), the angle of reflection will be
(a) 20°
(b) 40°
(c) 0°
(d) 70°
Answer:
(a) 20°
(v) Which law is verified in all three cases?
(a) Snell’s law
(b) Law of refraction
(c) Law of reflection
(d) Law of dispersion
Answer:
(c) Law of reflection
Light Mirrors and Lenses Class 8 Fill in the blanks
1. A _____________ mirror always forms a virtual, erect and diminished image.
Answer:
convex
2. When a convex lens is cut horizontally through its centre, the bottom half will _____________ light rays.
Answer:
converge
3. The phenomenon of bouncing back of light after striking a smooth surface is called _____________ .
Answer:
reflection
4. The incident ray, reflected ray and normal all lie in the _____________ plane.
Answer:
same
5. A student observes that the image formed by a mirror is always erect and smaller than the object. This mirror must be _____________ .
Answer:
convex mirror
6. When you look through a lens and see your image enlarged, but moving the lens away makes the image disappear, this must be a _____________ lens held _____________ .
Answer:
convex, closer
7. The image formed by a plane mirror is ____________ and of the same as the object.
Answer:
Virtual and size
8. Convex mirrors always form ____________ and ____________ images.
Answer:
Virtual and erect
9. In lateral inversion, the ____________ side of the object appears on the ____________ side in the mirror.
Answer:
left and right
Light Mirrors and Lenses Class 8 True or False
1. A convex lens always forms magnified images.
Answer:
False
2. The angle of incidence equals the angle of reflection for all surfaces.
Answer:
False
3. Concave lenses are thicker at the centre than edges.
Answer:
False
4. The angle of incidence can be greater than the angle of reflection on rough surfaces.
Answer:
False
5. The second law of reflection states that the incident ray and reflected ray must be perpendicular to each other.
Answer:
False
6. Dentists’ mirrors are concave because they form real, inverted images of teeth.
Answer:
False
7. In a mirror experiment, if the incident ray makes 0° angle with the normal, the reflected ray will coincide with the normal.
Answer:
True
8. A convex lens used as a magnifying glass forms a diminished virtual image.
Answer:
False
9. A convex lens is thicker at the centre than at its edges.
Answer:
True
10. The image formed by a plane mirror is laterally inverted.
Answer:
True
Light Mirrors and Lenses Class 8 Match the following
Question 1.
| Column I (Concept) | Column II (Explanations/Image/Use) |
| A. First law of reflection | 1. The image appears left-right reversed |
| B. Second law of reflection | 2. Angle of incidence = Angle of reflection |
| C. Plane mirror | 3. Incident ray, reflected ray and normal lie in same plane |
| D. Lateral inversion | 4. Forms virtual erect, same-size image |
| E. Rear-view mirror in vehicles | 5. Convex mirror – wide field of view |
Answer
A – 2, B – 3, C – 4, D – 1, E – 5
| Column I (Concept) | Column II (Explanations/Image/Use) |
| A. First law of reflection | 2. Angle of incidence = Angle of reflection |
| B. Second law of reflection | 3. Incident ray, reflected ray and normal lie in same plane |
| C. Plane mirror | 4. Forms virtual erect, same-size image |
| D. Lateral inversion | 1. The image appears left-right reversed |
| E. Rear-view mirror in vehicles | 5. Convex mirror – wide field of view |