Physics - Geometrical Optics Question with Solution | TestHub

Given that refractive of liquid is equal to refractive index of lens. $\Rightarrow n_{\text{lens }}=n_{\text{liquid }}$ Let the focal length be $f$. From lens makers formula, we get $\frac{1}{f}=\frac{\left(n_{\text{lens }}-n_{\text{liquid }}\right)}{n_{\text{liquid }}}\left(\frac{1}{R_1}-\frac{1}{R_2}\right)$ Here, $n_{\{\text{lens }\}}-n_{\{\text{liquid }\}}=0$ Therefore, the focal length will be infinite.