JEE Main | 2014Geometrical OpticsHard
Question
Thin convex lens made from crown glass 
has focal length f. When it is measured in two different liquids having refractive indices 
and 
it has the focal lengths f1 and f2 respectively. The correct relation between the focal lengths is
has focal length f. When it is measured in two different liquids having refractive indices and it has the focal lengths f1 and f2 respectively. The correct relation between the focal lengths is Options
A.f1 = f2 < f
B.f1 > f and f2 becomes negative
C.f2 > f and f1 becomes negative
D.f1 and f2 both become negative
Solution
By Lens maker′s formula
⇒ f1 = 4f & f2 = - 5f
⇒ f1 = 4f & f2 = - 5f
Create a free account to view solution
View Solution FreeMore Geometrical Optics Questions
Consider three media $P,Q$ and $R$ with refractive indices $1,1.25$, and 1.5 respectively. The medium $Q$ having a thick...A thin prism P1 with angle 6o and made from glass of refractive index 1.54 is combined with another thin prism P2 of ref...A ray of light travelling in a transparent medium falls on a surface separating the medium from air at an angle of incid...Focal length of the objective and eye-piece of an astronomical telescope are 20 cm and 10cm. If final image is at the mi...A boy stands straight infront of a mirror at a distance of 30 cm away from it. He sees his erect image whose height is 1...