Question

differentiate between principal focus and Focal length..?​

Answer 1

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Principal focus is a point (on the principal axis) where parallel incident rays meet after reflecting (in mirrors) or refracting (in lenses). ... Principal Focus also determines the focal length of the lens/mirror. Focus is just a random point where some rays meet, it might be at the principal focus or otherwise.

Answer 2

Answer:

Oh really

Explanation:

Then choose anyone else