Geometrical OpticsHard
Question
In the displacement method for determining the focal length of a convex lens, the lens is displaced by distance x to again obtain a sharp image on the screen. If the magnification in two positions are m1 and m2 respectively, the focal length of the lens is
Options
A.
B.
C.
D.
Solution
For convex lens

.......(i)
m1 - m2 =
.......(ii)
x = v - u .......(iii)
Using (i) & (ii) & (iii)
f =
m1 - m2 =
x = v - u .......(iii)
Using (i) & (ii) & (iii)
f =
Create a free account to view solution
View Solution FreeMore Geometrical Optics Questions
Monochromatic light is refracted from air into the glass of refractive index m. The ratio of the wavelength of incident ...A ray of light travelling in air have wavelength λ , frequency n, velocity V and intensity I. If this ray enters in...A ray of light travelling in a transparent medium of refractive index μ, falls on a surfaces parting the medium fro...A lens of focal length ′f′ is placed in between an object and screen at a distance ′D′. The lens...An isoscales prism of angle 120o has a refrective index 1.44. Two parallel rays of monochromatic light enter the prism p...