Define Focal Length Of Divergent Lens

(a) Define focal length of a divergent lens. (b) A divergent lens of focal length 30 cm … to show the formation of image in the…


(a) The focus of a divergent i.e. concave lens is the point on the principal axis from which the light rays parallel to the axis is diverged after passing through the lens. The distance between the pole of the concave lens and principal focus is called Focal length.

 (b) Given: Focal length. f =-30 cm

Size of the object, h = 6 cm

Image distance, v = -15 cm