A Biconvex Lens Made of a Transparent Material of Refractive Index 1.5 is Immersed in Water of Refractive Index 1.33. Will the Lens Behave as a Converging Or a Diverging Lens? Give Reason. - Physics


A biconvex lens made of a transparent material of refractive index 1.5 is immersed in water of refractive index 1.33. Will the lens behave as a converging or a diverging lens? Give reason.



A biconvex lens acts as a converging lens in air because the refractive index of air is less than that of the material of the lens. The refractive index of water (1.33) is also less than the refractive index of the material of the lens (1.5). So, it will behave as a converging lens.

Concept: Magnification
  Is there an error in this question or solution?
2013-2014 (March) All India Set 2

Video TutorialsVIEW ALL [1]


A biconvex lens with its two faces of equal radius of curvature R is made of a transparent medium of refractive index μ1. It is kept in contact with a medium of refractive index μ2 as shown in the figure.

(a) Find the equivalent focal length of the combination.
(b) Obtain the condition when this combination acts as a diverging lens.
(c) Draw the ray diagram for the case μ1 > (μ2 + 1) / 2, when the object is kept far away from the lens. Point out the nature of the image formed by the system.

name the factors on which  'limit of resolution' depends ?

The size of an object as perceived by an eye depends primarily on

To increase the angular magnification of a simple microscope, one should increase ______.

A simple microscope has a magnifying power of 3.0 when the image is formed at the near point (25 cm) of a normal eye. (a) What is its focal length? (b) What will be its magnifying power if the image is formed at infinity?

A child has near point at 10 cm. What is the maximum angular magnification the child can have with a convex lens of focal length 10 cm?

Find the maximum magnifying power of a compound microscope having a 25 diopter lens as the objective, a 5 diopter lens as the eyepiece and the separation 30 cm between the two lenses. The least distance for clear vision is 25 cm.

The angular magnification of a system is less than one. Does it mean that the image formed is inverted?

A magnifying glass is a converging lens placed close to the eye. A farsighted person uses spectacles having converging lenses. Compare the functions of a converging lens used as a magnifying glass and as spectacles.

The magnifying power of a simple microscope is given by `1+D/f` , where D is the least distance for clear vision. For farsighted persons, D is greater than the usual. Does it mean that the magnifying power of a simple microscope is greater for a farsighted person as compared to a normal person? Does it mean that a farsighted person can see an insect more clearly under a microscope than a normal person?

Why are the magnification properties of microscopes and telescopes defined in terms of the ratio of angles and not in terms of the ratio of sizes of objects and images?

A compound microscope has a magnifying power of 100 when the image is formed at infinity. The objective has a focal length of 0.5 cm and the tube length is 6.5 cm. Find the focal length of the eyepiece.

An optical instrument used for angular magnification has a 25 D objective and 20 D eyepiece. The tube length is 25 cm when the eye is least strained. (a) Whether it is a microscope or a telescope? (b) What is the angular magnification produced?

How does focal length of a convex lens change with increase in wavelength of incident light?

Magnification for spherical mirrors m is given by ______.

The focal length of the objective of a telescope is 60 cm. To obtain a magnification of 20, the focal length of the eye piece should be:


      Forgot password?
Use app×