Mirror formula.pptx

cbse 11 th mirror formula slieshow

1. Mirror Formula  

2. Magnification Magnification is the ratio of image height to object height. The magnitude of m shows whether the object is enlarged or diminished. m= 1  same m >1  enlarged m <1 - diminished The sign of m shows whether the image is erect or inverted.  

3. Magnification and nature of image magnification m Enlarged / diminished Erect/ Inverted Real/Virtual Possible mirror 2 E E V CONCAVE 0.5 D E V CONVEX -3 E I R CONCAVE -1/3 D I R CONCAVE -5/2 E I R CONCAVE 3/5 D E V CONVEX 1 SAME SIZE E V PLANE -1 SAME SIZE I R CONCAVE

4. An object is placed at a distance 15 cm in front of a concave mirror of focal length 10 cm.Find the position and nature of image.

5. An object of height 2 cm is placed at a distance 25 cm in front of a concave mirror of focal length 10 cm.Find the position , size and nature of image.

6. An object is placed at a distance 10 cm in front of a concave mirror of focal length 15 cm.Find the position and nature of image.

7. An object is placed at a distance 15 cm in front of a convex mirror of radius of curvature 20 cm.Find the position and nature of image.

8. An object of height 2 cm is placed at a distance 25 cm in front of a convex mirror of radius of curvature 20 cm.Find the position and nature of image.

9. At what distance from a concave mirror of focal length 15 cm will you place an object to get a 3 times magnified a) real image b) Virtual image

10. At what distance from a concave mirror of focal length 20 cm will you place a screen to get an image half the size of object?