1. An object is placed at a distance of 10 cm from a convex mirror of focal length 15
cm. Find the position and nature of the image. Comparison with a plane mirror image?
2. Two plane mirrors are kept inclined at an angle of 60 degrees. Find the number of
images formed of an object placed between them.
3. A concave mirror produces a three times magnified (real) image of an object placed
at 10 cm. Where is the image located? If the object is moved 5 cm towards the mirror, what happens?
4. Explain why a ray of light passing through the center of curvature of a concave
mirror gets reflected back along the same path.
5. Rohini wants to see an erect image of her face using a concave mirror of focal
length 20 cm. What should be the range of distance of the mirror from her face? Draw a ray diagram.
6. A security mirror in a shop is a convex mirror. If a customer is standing 5 m
away, where does the shopkeeper see the image?
7. Discuss the advantages of using a convex mirror as a rear-view mirror over a plane
mirror.
8. If the lower half of a concave mirror's reflecting surface is covered with an
opaque material, what will be the effect on the image?
9. An object 4 cm in height is placed at 25 cm in front of a concave mirror of focal
length 15 cm. At what distance from the mirror should a screen be placed to obtain a sharp image? Find the
size of the image.
10. Draw ray diagrams to distinguish between real and virtual images formed by
spherical mirrors.
11. Light travels from air into diamond. It is observed that the speed of light
reduces significantly. Calculate percentage reduction if $n=2.42$.
12. A coin placed at the bottom of a water tank appears raised. Explain this
phenomenon with a ray diagram. What implies the extent of raising?
13. A 5 cm tall object is placed perpendicular to the principal axis of a convex lens
of focal length 20 cm. The distance of the object from the lens is 30 cm. Find the position, nature, and
size.
14. A concave lens has focal length 15 cm. At what distance should the object be
placed from the lens so that it forms an image 10 cm from the lens? Also find the magnification.
15. What is the power of a combination of a convex lens of focal length 40 cm and a
concave lens of focal length 25 cm? Is the system converging or diverging?
16. Draw the ray diagram for the formation of image by a convex lens when object is
at infinity, 2F, and between F and O.
17. A convex lens forms a virtual, erect and magnified image. Where is the object
placed? Draw a ray diagram to show this formation.
18. Why does a light ray incident normally on a rectangular glass slab not suffer any
refraction?
19. Prove that for a rectangular glass slab, the emergent ray is parallel to the
incident ray.
20. One half of a convex lens is covered with a black paper. Will this lens produce a
complete image of the object? Verify your answer experimentally.
21. Explan why convex mirrors have a wider field of view than plane mirrors. Draw a
diagram to support your answer.
22. Why are concave mirrors used in solar furnaces? Explain the principle involved.
23. "A lens can be considered as a series of prisms." Explain how this leads to
convergence in convex lenses and divergence in concave lenses.
24. Differentiate between Real and Virtual images with respect to: (a) Inversion, (b)
Projection on screen, (c) Mirror/Lens type producing it.
25. Explain the principle of Reversibility of Light with a daily life example.
26. A stick partially immersed in water appears bent at the interface. Explain why
using a ray diagram.
27. How does the focal length of a glass lens change if it is dipped in water?
(Increase/Decrease). Give reason.
28. Define absolute refractive index. Why can it never be less than 1?
29. What factors affect the lateral displacement of light through a glass slab?
30. A convex lens covers an object. If the lens is broken into two pieces, will the
full image still form? Explain.
31. In an experiment to trace the path of a ray of light through a rectangular glass
slab, four students measured the angles of incidence (i), refraction (r), and emergence (e). What implies
the correct relation between them?
32. How can you distinguish between a plane mirror, a convex mirror, and a concave
mirror without touching them?
33. You are given water, kerosene, turpentine, and diamond. In which of these does
light travel fastest? Support your answer.
34. A student uses a convex lens to focus a distant building on a screen. If he moves
the lens slightly towards the screen, what happens to the image?
35. Design an experiment to find the focal length of a concave mirror using a distant
object.
36. A person needs a lens of power -5.5 dioptres for correcting his distant vision.
For correcting his near vision he needs a lens of power +1.5 dioptre. What is the focal length of the lens
required for correcting (i) distant vision, and (ii) near vision?
37. An object is placed at a distance of 60 cm from a concave lens of focal length 30
cm. Find the image position and magnification.
38. Light enters from air into diamond with refractive index 2.42. Calculate the
speed of light in diamond.
39. Define the Power of a lens. What is the SI unit? Find the power of a concave lens
of focal length 2 m.
40. A convex lens forms a real and inverted image 50 cm from the optical center. If
the image is of the same size as the object, where is the object placed? Find the power of the lens.
