For the given data showing object distance and focal length of three concave mirrors, answer the following questions:
S No
Object distance (cm)
Focal length (cm)
1.
30
20
2.
10
15
3.
20
10
1. Out of the three in which case the mirror will form the image having same size as the object?
2. Which mirror is being used as a make-up mirror?
3. Draw the ray diagram for part 1. and part 2.
Plz explain me the answer for these i.e., how do we identify??
Have a look at the following ray diagrams
(1) The image is of the same size as the object if it is placed at the center of curvature (2F). So, the object distance is this case would be twice the focal length.
The correct answer is thus part (3) where u = 20cm and f = 10cm.
(2) Concave mirror is used as a makeup mirror because it can magnify the object.
(3)
ray diagram for part 1
ray diagram for part 2
