Question

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??

Answer 1

1. Ans.3rd part. Because when object is at centre of curvature the image formed is of the same size. So object distance = 20cm. And Focal length=10 cm.

2. Ans.2nd part as object is between pole and focus. The object distance ia 10cm. And focal length is 15cm i.e b/w Pole and Focus.

Answer 2

Answer: 1. 3

              2.2

Explanation:

1. Ans.3rd part. Because when object is at center of curvature the image formed is of the same size. So object distance = 20 cm. And Focal length=10 cm.

2. Ans.2nd part as object is between pole and focus. The object distance is 10 cm. And focal length is 15 cm i.e b/w Pole and Focus.