Question

Define the following terms a) Local length b) Principal axis​

Answer 1

Answer:

Principal axis: The line joining the centre of curvature and the optical centre is called the principal axis. Aperture: This is the length or breadth of the lens through which refraction takes place. Principal focus: A light ray parallel to the principal axis of the lens meets at a point on the principal axis.

Answer 2

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Explanation:

(vi) Focal length is defined as the distance between the optical center and principal focus of the lens. (b) Given: Convex lens (converging lens) Focal length of the lens f = +12 cm Image distance, v= +48 cm Applying the lens formula: Thus, u=-16 cm. The object should be placed at a distance of 16 cm from the lens.