Question
Fri December 02, 2011 By:
 

Sir can you tell me the sign conventions for solving numericals related to power of lens required to correct any defect..what should be considered as 'v' and'u'..and whyyy???

Expert Reply
Sat December 03, 2011

Spherical Mirrors Lenses

Focal Length (f)

+ for concave mirrors + for a converging lens

- for convex mirrors - for a diverging lens

Object Distance (do)

+ if object is in front of the mirror (real object) + if the object is to the left of the lens (real object)

- if object is behind the mirror (virtual object)

* - if the object is to the right of the lens (virtual object)

 

 

Image Distance (
di)

+ if the image is in front of the mirror (real image) + for an image (real) formed to the right of the lens by a real object

- if the image is behind the mirror (virtual image) - for an image (virtual) formed to the left of the lens by a real object

Magnification (m)

+ for an image that is upright with respect to the object + for an image that is upright with respect to the object

- for an image that is inverted with respect to the object -for an image that is inverted with respect to the object.
Home Work Help