A student has three concave mirrors A B and C of focal lengths 20cm, 15cm and 10cm respectively. For each concave mirror he performs the experiment of image formation for three values of object distance of 30cm, 10cm and 20cm. Giving reason answer the following: 1. For the theree object distances identify the mirror which will form an image equal in size to that of object. Find atleast one value of object distance. 2. Out of the three mirrors identify the mirror which would be used for shaving purpose. 3. For the mirror B draw ray diagram for image formation for any two given values of object distance.



For u. focal Len.
30 cm - 15cm
20cm - 10cm
for object placed 20 cm away the u should be 40 then a same sized image will be formed. 2. no one because shaving mirror is convex always to see large sized image