Optics Question 592
Question: A glass lens is placed in a medium in which it is found to behave like a glass plate. Refractive index of the medium will be
[CPMT 1981, 84, 85]
Options:
A) Greater than the refractive index of glass
B) Smaller than the refractive index of glass
C) Equal to refractive index of glass
D) No case will be possible from above
Show Answer
Answer:
Correct Answer: C
Solution:
$ \frac{f _{l}}{f _{a}}=\frac{{( _{a}}{\mu _{g}}-1)}{{( _{l}}{\mu _{g}}-1)} $
Therefore $ f _{l}=\infty $ if $ _{l}{\mu _{g}}=1 $
Therefore $ _{a}{\mu _{l}}{= _{a}}{\mu _{g}} $ .
