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प्रश्न
What are primary focus and secondary focus of convex lens?
उत्तर
- Primary focus:
The primary focus F1 is defined as a point where an object should be placed to give parallel emergent rays to the principal axis. - Secondary focus:
The secondary focus F2 is defined as a point where all the parallel rays travelling close to the principal axis converge to form an image on the principal axis.
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