An object is placed at a distance 20 cm from a convex lens of focal length 10 cm . Find the image distance and nature of the image .

Explanation

Given Object distance , u=-20 cm
Focal length of convex lens f=10 cm
To find : Image distance v= ? And
Nature of the image = ?
If the object is placed on the left side of the lens, then `f=10 cm, u=-20 cm`
`1/f =1/v -1/u`
`1/v =1/f +1/u`
`1/v =1/(10) +(1)/((-20))`
`1/v =1/(10) -1/(20) =(1)/(20)`
Distance of the image v=20 cm
Enlarged and inverted image at a distance of 20 cm on the right side of the lens.
`m= v/u =(20)/(-20) =-1`
(-ve sign indicates the inverted image).
[Nature of the image]