KVPY SA Exam 2016 Question Paper

${\mathrm{\mu }}_{\mathrm{air}}=1$
${\mathrm{\mu }}_{\mathrm{water}}=1.33$
${\mathrm{\mu }}_{{\mathrm{cs}}_2}=1.6$$\frac{1}{\mathit{f}}=\left(\frac{{\mathit{n}}_2}{{\mathit{n}}_1}-1\right)\left[-\frac{1}{{\mathit{R}}_1}-\frac{1}{{\mathit{R}}_2}\right]$
$\frac{1}{\mathit{f}}=-\left(\frac{{\mathit{n}}_2}{{\mathit{n}}_1}-1\right)\left[\frac{1}{{\mathit{R}}_1}+\frac{1}{{\mathit{R}}_2}\right]$
for diverging lens f must be – ve.
∴ for this $\frac{{\mathit{n}}_2}{{\mathit{n}}_1}>1\Rightarrow {\mathit{n}}_2>{\mathit{n}}_1$
∴ Lens should be filled with liquid which has more refractive index in comparison to liquid in which lens is immersed.
∴ Ans (D) is the correct option as
${\mathrm{\mu }}_{{\mathrm{cs}}_2}>{\mathrm{\mu }}_{\mathrm{water}}$