# CBSE Class 10 - Physics - Light - Reflection and Refraction (MCQs)

Q1: The laws of reflection hold true for:

(a) plane mirrors only

(b) concave mirrors only

(c) convex mirrors only

(d) all reflecting surfaces

Q2: Focal length of a plane mirror is

(a) zero

(b) infinite

(c) 25 cm

(d) -25 cm

Q3: An object is placed 40.0 cm in front of a convex mirror. The image appears 15 cm behind the mirror. What is the focal length of the mirror?

(a) +24 cm

(b) +11 cm

(c) -11 cm

(d) -24 cm

Q4: Rays from Sun converge at a point 15 cm in front of a concave mirror. Where should an object be placed so that size of its image is equal to the size of the object?

(a) 15 cm in front of the mirror

(b) 30 cm in front of the mirror

(c) between 15 cm and 30 cm in front of the mirror

(d) more than 30 cm in front of the mirror

Q5: An object at a distance of + 15 cm is slowly moved towards the pole of a convex mirror. The image will get

(a) shortened and real

(b) enlarged and real

(c) enlarged and virtual

(d) diminished and virtual

Q6: Magnification produced by a rearview mirror fitted in vehicles

(a) is less than one

(b) is more than one

(c) is equal to one

(d) vary as per the position of the object.

Q7: Chose the correct relation between u, v and r?

Q8: A real image is formed by the light rays after reflection or refraction when they

I  Actually meet or intersect with each other.

II  Actually converge at a point

III Appear to meet when they are produced in the backward direction

IV Appear to diverge from a point.

When of the given statements are correct?

(a) I and IV

(b) II and IV

(c) I and II

(d) III and IV

Q9: Velocity of light in air is 3 × 10⁸ m/s. While its velocity in a medium is 1.5 × 10⁸ m/s. Then, refractive index of this medium is

(a) 3

(b) 5

(c) 0.5

(d) 2

Q10: Which of the following statements is/are true?

(a) A convex lens has +4D power having a focal length of 0.25 m

(b) A convex lens has -4D power having a focal length of 0.25 m

(c) A concave lens has +4D power having a focal length of 0.25 m

(d) A concave lens has –4D having a focal length of 0.25 m

Q11: Rahul conducts an experiment using an object of height 10 cm and a concave lens with a focal length of 20 cm. The object is placed at a distance of 25 cm from the lens. Can the image be formed on a screen?

(a) Yes, as the image formed will be real.

(b) No, as the image formed will be inverted.

(c) No, as the image formed will be virtual.

(d) Yes, as the image formed will be erect

Q12: A convex lens of refractive index n₁ is placed in an enclosed chamber filled with a gas of refractive index n₂. If n₂ = n1, light rays passing through the convex lens will:

(a) converge

(b) pass straight

(c) diverge

(d) none of these

Q13: A convex lens of refractive index n₁ is placed in an enclosed chamber filled with a gas of refractive index n₂. If n₂ > n1, light rays passing through the convex lens will:

(a) converge

(b) pass straight

(c) diverge

(d) none of these

Q14: In a rectangular glass slab experiment, if the incident light is normal to the surface, the angle of emergence is

(a) 0°

(b) 30°

(c) 45°

(d) 90°

Q15: Double refraction takes place in

(a) rectangular glass slab only

(b) convex lens only

(c) concave lens only

(d) all of these

1: (d) all reflecting surfaces

2: (b) infinite

3: (a) +24 cm

u = -40cm, v = +15cm. Using mirror formula 1/v + 1/u = 1/f

1/f = (u+v)/uv = (-40+15)/(-40×15) = (-25)/(-600) = 24

f = +24cm

4: (b) 30 cm in front of the mirror

Here f = 15cm. To make image height = object height, object must be placed at Centre of curvate (C) i.e. 2f = 30cm

5: (d) diminished and virtual

6: (a) is less than one

Convex mirrors always produce diminished and virtual images. h' < h. ∴ m < 1

7: (b) 2uv/(u+v)

8: (c) I and II

9: (d) 2

10: (a) A convex lens has +4D power having a focal length of 0.25 m

11: (c) No, as the image formed will be virtual.

12: (b) pass straight (both media have same RI) See blog Q3 and Q4

13: (c) diverge (gas RI > lens RI) See blog post

14: (a) 0°

15: (d) all of these  