Question

Q10. Anita took lens ‘A’ and placed a burning candle 15 cm in front of lens A having
length of 10 cm. She observed the image of the candle flame to be inverted and it was formed at
a distance of 30 cm behind A. 'A' is a lens. Draw a well labeled ray diagram for the
same and identify the nature of the image formed.

Answer 1

Answer:

.like that

Explanation:

Magnification is 3 times and image distance v=80cm

Magnification =

u

v

Or,3=

u

80cm

Or, u=

3

80cm

since,object distance is taken as negative; as per sign convention so,

or, u=−

3

80cm

Nature of image: since image is formed on the other side of lens hence it is a real image and inverted image.

Nature of Lens: Enlarged image is formed by convex lens and not by concave lens, so it is a convex lens.

Answer 2

Answer:

Magnification is 3 times and image distance v=80cm

Magnification =  

u

v

​  

 

Or,3=  

u

80cm

​  

 

Or, u=  

3

80cm

​  

 

since,object distance is taken as negative; as per sign convention so,

or, u=−  

3

80cm

​  

 

Nature of image: since image is formed on the other side of lens hence it is a real image and inverted image.

Nature of Lens: Enlarged image is formed by convex lens and not by concave lens, so it is a convex lens.