A) 4
B) 6
C) 7.5
D) 9
Correct Answer: C
Solution :
For plane water surface. \[\frac{1}{v}\,-\frac{4/3}{(-u)}\,=\frac{1-4/3}{\infty }=0\] Or \[v=/00.75\,u\] For convex lens \[{{\mu }_{1}}=1,\,\,{{\mu }_{2}}=1\] \[{{u}_{1}}=-(0.75+0.5)\,u\] \[=-0.25\,u\] \[{{v}_{1}}=-(u+0.5u)\,=-1.5u\] Rays coming from air and viewed through air From \[\frac{1}{{{v}_{1}}}-\frac{1}{{{u}_{1}}}\,=\frac{1}{f}\] \[\frac{1}{1.5u}\,-\frac{1}{(-1.25u)}=\frac{1}{f}\] Or \[f=7.5\,u\]You need to login to perform this action.
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