The effective focal length of the lens combination shown in the figure is \(-60 cm\). The radii of curvature of the curved surfaces of the plano-convex lenses are \(12 cm\) each and refractive index of the material of the lens is 1.5 . What would be the refractive index of the liquid? 📲PW App Link - https://bit.ly/YTAI_PWAP 🌐PW Website - https://www.pw.live