What is the spherical mirror formula? Also, write down the sign conventions for the spherical mirror formula.

The spherical mirror formula relates the focal length ff, the object distance uu, and the image distance vv for a spherical mirror (concave or convex mirror). The formula is given as:

1/f=1/v+1/υ

Definitions:

  • f: Focal length of the mirror
  • v: Image distance (distance from the mirror to the image)
  • υ: Object distance (distance from the mirror to the object)

Sign Conventions for Spherical Mirrors:

In the context of spherical mirrors, the following sign conventions apply:

  1. Object Distance (υ):

    • For real objects,  is negative (since the object is in front of the mirror).
    • For virtual objects, υ is positive.
  2. Image Distance ():

    • For real images (formed on the same side as the object), v is positive.
    • For virtual images (formed on the opposite side of the object), is negative.
  3. Focal Length ():

    • For concave mirrors (converging mirrors), f is positive.
    • For convex mirrors (diverging mirrors), f is negative.
  4. Radius of Curvature (R):

    • The radius of curvature for the mirror is positive for concave mirrors and negative for convex mirrors. The focal length is related to the radius of curvature by the equation f=R/2
  5. Mirror Type:

    • Concave Mirror: Converging mirror, used to form real or virtual images.
    • Convex Mirror: Diverging mirror, always forms virtual images.

These sign conventions help maintain consistency in calculations for spherical mirrors.