Single Choice

A water drop in air refractes the light ray as

A
B
Correct Answer
C
D

Solution

A water drop in air has a higher refractive index as compared to air. And because of its convex shape, it has a tendency to converge a parallel beam of light falling onto it and therefore it acts as a converging lens.

SIMILAR QUESTIONS

Optics

Formation of real image using a biconvex lens is shown below: If the whole set up is immersed in water without disturbing the object and the screen position, what will one observe on the screen?

Optics

A thin convex lens made from crown glass $$\displaystyle \left ( \mu = \dfrac{3}{2} \right )$$ has focal length f. When it is measured in two different liquids having refractive indices $$\dfrac{4}{3}$$ and $$\dfrac{5}{3} $$, it has the focal lengths $$f_1$$ and $$f_2$$ respectively. The correct relation between the focal lengths is:

Optics

A thin lens is made with a material having refractive index $$\displaystyle \mu =1.5$$. Both the sides are convex. It is dipped in water ($$\displaystyle \mu =1.33$$), it will behave like:

Optics

The focal length of a convex lens when placed in air and then in water will :

Optics

The change in the focal length of the lens, if a convex lens of focal length $$20 cm$$ and refractive index $$1.5$$, is immersed in water having refractive index $$1.33$$, is :

Optics

The radii of curvature of the surfaces of a double convex lens are 20 cm and 40 cm respectively, and its focal length is 20 cm. What is the refractive index of the material of the lens?

Optics

A biconvex lens has a focal length 2/3 times the radius of curvature of either surface. The refractive index of the lens material is :

Optics

A thin converging lens with focal length $$ f=25 \mathrm{cm} $$ projects the image of an object on a screen removed from the lens by a distance l=5.0 m. the lens by a distance $$\Delta l=18cm$$. By what distance should the object be shifted for its image to become sharp again?

Optics

A source of light is located at a distance $$ l=90 \mathrm{cm} $$ from a screen. A thin converging lens provides the sharp image of the source when placed between the source of light and the screen at two positions. Determine the focal length of the lens if (a) the distance between the two positions of the lens is $$ \Delta l=30 \mathrm{cm} $$

Optics

A substance is behaving as convex lens in air and concave in water, then its refractive index is

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