Question

An object is placed at a distance of 10 cm from a convex mirror of focal length 5 cm.

(a) Draw a ray-diagram showing the formation image
(b) State two characteristics of the image formed
(c) Calculate the distance of the image from mirror.

Answer 1

(a) Ray Diagram- 

  

(b) Following are the characteristics of the image formed:

(1) It is virtual and erect.
(2) It is smaller than the object.

(c) Distance of the object 'u' = -10 cm
Focal length of the convex mirror is 5 cm.
We have to find the distance of the image 'v'.
Using the mirror formula, we get 

`1/f=1/v+1/u` 

⇒`1/5=1/v+1/-10` 

⇒`1/5=1/v-1/10` 

⇒`1/5+1/10=1/v` 

⇒`2/10+1/10=1/v` 

⇒`1/v=3/10` 

⇒`v=10/3` ⇒`v=3.3 cm ` 

Thus, the distance of the image is 3.3 cm behind the mirror.