Question no.18. Ans(2) P l a n e s u r f a c e o f p l a n o c o n v e x l e n s o f r e f r a c t i v e i n d e x ' μ ' a n d r a d i u s o f c u r v a t u r e R i s s i l v e r e d a n d o b j e c t i s p l a c e d i n f r o n t o f c u r v e d f a c e t h e n f o c a l l e n g t h o f l e n s i s ( 1 ) R 2 ( μ - 1 ) ( 2 ) - R 2 ( μ - 1 ) ( 3 ) 2 ( μ - 1 ) R ( 4 ) - 2 ( μ - 1 ) R Share with your friends Share 0 Vipra Mishra answered this Dear Student A silvered lens behave as concave mirror1F=2flens+1fmirrorHerefmirror= ∞1flens=μ-11R1-1R21flens=μ-11R-1∞flens=Rμ-11F=2Rμ-1+1∞F=R2μ-1 Regards 0 View Full Answer