Question

An object is kept at a distance of 5 cm in front of a convex mirror of focal length 10 cm. Calculate the position and magnification of the image and state its nature. 

Answer 1

Distance of the object from the mirror 'u' = -5 cm
Focal length of the mirror 'f '= 10 cm
We have to find the distance of the image 'v'.
Using the mirror formula, we get 

`1/f=1/v+1/u` 

⇒`1/10=1/v+1/-5` 

⇒`1/10=1/v-1/5` 

⇒`1/10+1/5=1/v` 

⇒`1/10+2/10=1/v` 

⇒`1/v=3/10` 

⇒`v=10/3` 

⇒`v=3.3` cm 

Thus, the distance of the image 'v' is 3.3 cm behind the mirror.Now, using the magnification formula, we get 

`m=(-v)/u` 

`m=(-3.3)/-5` 

m = 0.66 

Thus, the image is virtual, erect and small in size.