Focal length of a convex lens of refractive index 1.5 is 2 cm. Focal length of lens when immersed in a liquid of refractive index 1.25 will be
Answer & explanation
Correct answer: option 1
$\frac{f_p}{f_a}=\frac{(μ_g-1)}{(\frac{μ_g}{μ_I}-1)}⇒f_I=\frac{5}{2}xf_a$
$\frac{5}{2}×2cm=5cm$