Qstnid -I-13-a Single Lens Is Mounted In A Tube. A Parallel Beam Enters The Tube And Emerges Out Of The Tube As A Divergent Beam. Can You Say With Certainty That There Is A Diverging Lens In The Tube? - 18: Geometrical Optics

with Solutions -

#13
A single lens is mounted in a tube. A parallel beam enters the tube and emerges out of the tube as a divergent beam. Can you say with certainty that there is a diverging lens in the tube?
Ans : Yes, we can say so with certainty, as only a diverging lens can cause a parallel beam of light to diverge.
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