# Light Reflection Exercises

## Light Reflection Exercise

### Light Reflection Exercise – 1

Very Short Answer Type Questions

1. A ray of light is incident on a plane mirror, i being the angle of incidence. What is the deviation suffered by the ray of light?
2. A plane mirror reflects a pencil of light to form a real image. What is the nature of the pencil of light incident on the mirror?
3. Define principal axis of a spherical mirror.
4. What is the focal length of a plane mirror?
5. Two perpendicular plane mirror forms ………….. number of images of a point source of light.
6. What is the magnification produced by a plane mirror?
7. Which mirror would you use for shaving?
8. Suppose x and y are distances of object and image respectively from a mirror. What shall be the shape of the graph between $latex \frac{1}{x}$ and $latex \frac{1}{y}$ for a concave mirror?

Short Answer Type Questions

1. An object is placed between two plane parallel mirrors. Why do the distant images get fainter and fainter?
2. Why mirrors used in search light are parabolic and not concave spherical?
3. You read a newspaper because of the light that it reflects. Then why do you not see even a faint image of yourself in the newspaper?
4. If you were driving a car, what type of mirror would you prefer to use for observing traffic at your back and why?
5. We known that plane and convex mirrors produce virtual images of objects. Can they produce real images under some circumstances ? Explain
6. The wall of a room is covered with perfect plane mirror. Two movie films are made, one recording the movement of a man and the other of his mirror image. From viewing the films later, can an outsider tell which is which?
7. A concave mirror is held in water. What would be the change in the focal length of the mirror?
8. What is the difference between the virtual images produced by (i) plane mirror, (ii) concave mirror, (iii) convex mirror?
9. Show that if a ray of light is reflected successively from two mirrors inclined at an angle q, the deviation of the ray does not depend upon the angle of incidence.
10. Use the mirror equation to deduce that an object placed between f and 2f of a concave mirror produces a real image beyond 2f.
11. Show that a convex mirror always produces a virtual image independent of the location of the object.
12. Prove that the virtual image produced by a convex mirror is always diminished in size and is located between the focus and the pole.
13. Show analytically that an object placed between the pole and focus of a concave mirror produces a virtual and enlarged image.
14. We know that a virtual  image cannot be obtained on a screen. But when we see a virtual image, we are obviously bringing it on the retina (may be regarded as a screen) of the eye. Point out the contradiction, if any.
15. Why a concave mirror of small aperture forms a sharper image?
16. What do you understand by the term ‘parallax’?
17. How can you distinguish between three different mirrors just by looking at them?
18. What is the effect of size of mirror on the nature of image ?
19. Is irregular reflection follows the laws of reflections or not ?

Long Answer Type Questions

1. Prove that the radius of curvature of a spherical mirror is equal to twice the focal length of the mirror.
2. Derive mirror formula for a concave mirror when image formed is (i) real (ii) virtual Also give the sign convention used.
3. Find formulae for  magnification produced in the following cases : (i) concave mirror, when image formed is real (ii) concave mirror, when image formed is virtual (ii) convex mirror.
4. Draw a ray diagram to show the formation of image of an object placed between the pole and centre of curvature of a concave mirror. Derive the formula connecting object distance (u), image distance (ν) and focal length (f) for this particular case for the given concave mirror. State clearly the assumptions and sign conventions used.
5. Express magnification produced by a spherical mirror in terms of (i) u and f(ii) u and f.