When will the magnification be positive and negative?

Discussion in 'CBSE Class 10 Physics Help' started by Vinila Choudary, Jan 19, 2012.

  1. Vinila Choudary

    Vinila Choudary Active Member

    Give an expression relating the object distance it, image distance v and focal length f of a mirror. Also give an expression for magnification of a mirror. When will the magnification be positive and negative?

    Mirror formula is 1/v +1/u = 1/f


    where v is image distance, u is object distance and f is the focal length of a mirror. Magnification: The ratio of the height of the image to the height of the object is called the magnification of the spherical mirror.

    Magmfication, m = Height of the image (b')/Height of the object (b) = v/u

    Magnification of a real image will always be negative and that of a virtual image be always positive.

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