Class 9 Test Reflection of light set 1 Full marks -50

1. Explain the following terms:

(a) Plane mirror,  (b) Incident ray,  (c) Reflected ray,  (d) Angle of incidence and    (e) Angle of reflection.

Draw diagram/diagrams to show them  (5)

2. An object is kept at 60 cm in front of a plane mirror. If the mirror is now moved 25 cm towards the object, how does the image shift from its previous position?  (2)

3. An optician while testing the eyes of a patient keeps a chart of letters 3 m behind the patient and asks him to see the letters on the image of chart formed in a plane mirror kept at distance 2 m in front of him. How far away is the chart seen by the patient?   (3)

4. A light ray is incident normally on a plane mirror. (a) What is its angle of incidence?

(b) What is the direction of reflected ray? Show it on a diagram. (2)

5. State the two laws of reflection of light. (2)

6. What is meant by lateral inversion of an image in a plane mirror? Explain it with the help of a ray diagram. (3)

7. Two plane mirrors are placed making an angle theta between them. Write an expression for the number of images formed of an object placed in between the mirrors. State the condition, if any. (3)

8. Two plane mirrors are placed making an angle 72 degree in between them. For an object placed in between the mirrors (asymmetrically) , the number of images formed will be : (2)

9.Name the two kinds of spherical mirrors and distinguish between them. (2)

10. An object is placed at 4 cm distance in front of a concave mirror of radius of curvature 24 cm. Find the position of image by drawing. Is the image magnified? (3)

11. Explain the meaning of the terms focus and focal length in case of a convex mirror, with the help of suitable ray diagram. (3)

12. A point light source is kept in front of a convex mirror at a distance of 40 cm. The focal length of the mirror is 40 cm. Find the position of image by drawing. (3)

13. State the direction of incident ray which after reflection from a spherical mirror retraces its path. Give a reason to your answer. (2)

14. When an object of height 1 cm is kept at a distance 4 cm from a concave mirror, its erect image of height 1.5 cm is formed at a distance 6 cm behind the mirror. Find the focal length of mirror, by drawing. (3)

15. An object of length 4 cm is placed in front of a concave mirror at distance 30 cm. The focal length of mirror is 15 cm.

a. Where will the image form?     b. What will be the length of image?   (3)

16. Why does a driver use a convex mirror as a rear view mirror? Illustrate your answer with the help of a ray diagram. (2)

17. State the kind of mirror used

(a) By a dentist,    (b) As a search-light reflector. (2)

18. At what maximum distance the image in a convex mirror can be obtained? What will be the location of object then? (2)

19. A ray of light is incident on a plane mirror at an angle of incidence of 50 degree. What is the angle (i) of reflection (ii) between the incident ray and the mirror (iii) between the reflected ray and the mirror (iv) of deviation (angle between the directions of the incident ray and the reflected ray)? (3)