why presently sign convention is known as new sign convention

Asked by alimohd1487 | 3rd Jan, 2021, 06:40: PM

Expert Answer:

The sign convention followed for spherical mirrors and spherical lenses that is similar to sign convention of
cartesian coordinate system is called New Cartesian sign convention.
 
It is easy to follow and easy to remember because we are very much familiar to Cartesian coordinate system.
 
It is assumed in this sign convention, pole of the mirror or optical centre of lens is at origin of cartesian coordinate system.
 
Distances parallel to optical axis are measured by taking  pole of the mirror or optical centre of lens because origin is there
at pole of mirror or optical centre of lens.
 
Distances parallel to optical axis which are right of pole of mirror or optical centre of lens are +ve . 
Distances parallel to optical axis which are left of pole of mirror or optical centre of lens are -ve .
 
Distances perpendicular to optical axis are measured by taking optical axis as reference and given sign as per cartesian
coordinate system, i.e., distances measured upward from optic axis are +ve  and distances measured downward from
optic axis are negative. 

Answered by Thiyagarajan K | 3rd Jan, 2021, 08:04: PM