Recent questions tagged ray-optics-and-optical-instruments

The refractive indices of flint glass for red and violet light are 1.613 and 1.632 respectively. Find the angular dispersion produced by a thin prism of flint glass having refracting angle $15 ^{\circ}$

asked Apr 19, 2014 by balaji.thirumalai

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A right angle prism $(45^{\circ} - 90^{\circ}- 45^{\circ})$ of refractive index n has a plate of refractive index $n_1\;( n_1 < n ) $ to its diagonal wall. The assembly is in air. A ray is incident at AB . Then the angle of incidence at AB for which the ray strikes the diagonal face at critical angle is :-

asked Feb 20, 2014 by meena.p

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A light ray enters into a medium whose refractive index varies along x-axis as $y(x) = \mu_{circ} \sqrt {1+ 0.25 x}.$ Where $\mu_0=1$.The medium is bounded by the planes $x=0,x=1\;cm$ and $y=0$ . If the ray enters at an angle $\theta=30^{\circ}$ with horizontal . Then the trajectory of light ray is

asked Feb 20, 2014 by meena.p

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A hollow double concave lens is made of very thin transparent material It can be filled with air or either of two liquids $L_1$ or $L_2$ having refracting indices $n_1$ and $n_2$ respectively $( n_2 > n_1 > 1)$ The lens will diverge a parallel beam of light if it is filled with

asked Feb 19, 2014 by meena.p

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A short linear object of length b lies along the axis of a concave mirror of focal length f at a distance u from pole of mirror , The size of image is approximate equal to :

asked Feb 19, 2014 by meena.p

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An object is placed at $ A\;(OA > f)$ Here, f is the focal length of the lens. The image is formed at B, A perpendicular is erected at 0 and C is chooses such that $\angle BCA =90^{\circ}$. Let $OA=a,OB=b$ and $OC=c$ then f is :

asked Feb 19, 2014 by meena.p

1 answer

A point object O is placed at a distance o 20cm from a convex lens of focal 10 cm as shown. At what distance x from lens should a concave mirror of focal length 60 cm can be placed so that final image coincides with object.

asked Feb 19, 2014 by meena.p

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Optic axis of a thin equiconvex lens is the x-axis. The co-ordinates of a point object and its image are $(-40\;cm,1\;cm)$ and $(50\;cm,-2\;cm)$ respectively . lens is located at

asked Feb 19, 2014 by meena.p

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A circular beam of diameter $d=2 \;cm$ falls on a plane surface of glass . The angle of incidence is $60^{\circ}$ and refractive index of glass is $ \mu=\large\frac{3}{2}$. The diameter of the refracted beam is ,

asked Feb 19, 2014 by meena.p

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A concave mirror has a focal length 20 cm. The distance between the two positions of object for which the image size is double of object size.

asked Feb 19, 2014 by meena.p

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A convex lens forms a real image 3 times larger than the object on a screen. Object and screen are moved until the image becomes twice the size of object. If the shift of object is $6\;cm$ The shift of screen is :

asked Feb 19, 2014 by meena.p

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Refraction takes place at a concave spherical boundary separating glass air medium. For image to be real the object distance $(\mu g=\large\frac{3}{2})$

asked Feb 19, 2014 by meena.p

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A 2 cm diameter coin rests flat on the bottom of a bowl in which water is 20 cm deep $(\mu_w= \large\frac{4}{3})$. If the coin is viewed directly from above what is its apparently diameter?

asked Feb 19, 2014 by meena.p

1 answer

A plane mirror is made of glass slab $(\mu g=1.5)\;2.5\;cm$ thick and silvered on back. A point objected is placed 5 cm in front of unsilvered face of mirror. What will be the position of final image.

asked Feb 19, 2014 by meena.p

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The refractive index of a prism is 2. This prism can have a maximum refracting angle of

asked Feb 19, 2014 by meena.p

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A glass sphere with radius 10 cm has concentric spherical equity of radius 5 cm. A narrow beam of parallel light is directed into sphere, as shown . Find the position of final image from centre of sphere

asked Feb 19, 2014 by meena.p

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An observer can see through a pin hole the top end of a thin rod of height h, placed as shown. The beaker height is 3 h and its radius is h. When the beaker is filled with a liquid up to a height 2h ,he can see the lower end of the rod. Then RI of liquid is .

asked Feb 19, 2014 by meena.p

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A ray of light falls on a transparent glass slab with refractive index (relative to air) of $1.62$ . The angle of incident for which the reflected and refractive rays are mutually perpendicular is :

asked Feb 19, 2014 by meena.p

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Two lenses , One concave and the other convex of same power are placed such that their principal axes coincide. If the separation b/w the lenses is x, then ,

asked Feb 18, 2014 by meena.p

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A $16\;cm$ long image of an object is formed by a convex lens on a screen. On moving the lens towards the screen with out changing the positions of object an image of size 9 cm is again formed again on the screen . The size of object is

asked Feb 18, 2014 by meena.p

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A thin equiconvex lens of refractive index $\large\frac{3}{2}$ and radius of curvature 30 m is put in water $(RI= \large\frac{4}{3})$. Its focal length is

asked Feb 18, 2014 by meena.p

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A lens of focal length f projects m times magnified image of an object on a screen.The distance of screen from lens is

asked Feb 18, 2014 by meena.p

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A ray of light passes through an equilateral prism such that the angle of incidence and the angle of emergence are equal to $\large\frac{3}{4}th$ of the angle of prism. The angle of minimum deviation is

asked Feb 18, 2014 by meena.p

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A ray of light traveling in a transparent medium falls on a surface separating the medium from air at an angle of incidence of $45^{\circ}$ The ray undergoes total internal reflection . If n is the refractive index of medium with respect to air, select the possible value of n from following

asked Feb 18, 2014 by meena.p

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A diminished image of an object is to be obtained on a screen 1. m away from it . This can be achieved by approximately placing.

asked Feb 18, 2014 by meena.p

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A ray of light passes through four transparent media with refractive indices $\mu_1,\mu_2,\mu_3$ of all media are parallel, If the emergent ray CD is parallel ti incident ray AB. We must have

asked Feb 18, 2014 by meena.p

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Two plane mirrors A and B are aligned parallel to each other as shown. A light ray is incident at an angle of $30^{\circ}$ at a point just inside one end of A. The plane of incidence coincides with place of figure. The maximum number of time the ray undergoes reflections (including the first one ) before it emerges out is

asked Feb 18, 2014 by meena.p

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An equi - convex lens of crown and equi convex lens of flint glass make an achromatic system. The radium of curvature of convex lens is $0.54\;m$. If the focal length of combination for mean colour is 1.5 m and $RI$ for crown glass are $\mu _R= 1.53$ and $\mu_v =1.55$ Then the dispersive power of flint glass is

asked Feb 14, 2014 by meena.p

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A thin plano- convex lens of focal length f is split into two halves one of halves is shifted along the optical axis. The separation b/w object and image plane is 1.8 m. The magnification of image formed by one of half lenses is 2. Find the focal length of lens and separation b/w the two halves.

asked Feb 14, 2014 by meena.p

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The cross section of glass prism has the form of an isosceles triangle . One of equal face is silvered. A ray of light incident normally on other equal face and after being reflected twice, emerges through base of prism along normal. That the angle of prism is :-

asked Feb 14, 2014 by meena.p

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A lens has a power of +5 diopter in air what will be its power if completely immersed in water ? $ \mu_g =\large\frac{3}{2};$$ \mu_w=\large\frac{4}{3}$

asked Feb 14, 2014 by meena.p

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A point source of light is placed at the bottom of a tank containing a liquid $(R.I= \mu)$ upto a depth $h$. A bright circular spot is seen on the surface of the liquid. Then the radius of this bright spot.:

asked Feb 14, 2014 by meena.p

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In the figure shown for an angle of incidence i at the top surface , What is the minimum refractive index needed for total internal reflection at vertical face ?

asked Feb 14, 2014 by meena.p

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A 4 cm thick layer of water covers 6 cm thick glass slab. A coin is placed at the bottom of slab and is being observed from the air side along the normal to surface. Then the apparent position of coin surface is

asked Feb 13, 2014 by meena.p

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A pin is placed $10 cm$ in front of a convex lens of focal length $20 cm$ made of a material having refractive index $1.5$. The surface of lens is further away from P in is silvered and has a radius of curvature $22 \;cm$ Then position of final image will be :

asked Feb 13, 2014 by meena.p

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The focal length of a Plano convex lens when curved surface is silvered and object is in front of plane surface is :-

asked Feb 13, 2014 by meena.p

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The focal length of a Plano convex lens when plane surface is silvered and object is in front of curved surface is

asked Feb 13, 2014 by meena.p

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Two convex lenses of focal length 20 cm are placed co axially with separation of 60 cm between them. Find image of distant object.

asked Feb 12, 2014 by meena.p

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Convex lens of 10 cm focal length is combined with a concave lens of 6 cm focal length. Find focal length of combination.

asked Feb 12, 2014 by meena.p

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A lens has a power of +5 diopters in air. What will be power if completely immersed in water? $_a \mu_w =\large\frac{4}{3}$ and $_a \mu_g =\large\frac{3}{2}$

asked Feb 12, 2014 by meena.p

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A convergent lens of 6 diopters is combined with a diverging lens of -2 diopters.Then the power and focal length is

asked Feb 12, 2014 by meena.p

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An object is placed at an of 45 cm from a converging lens of focal length 30 cm . A mirror of radius of curvature 40 cm is to be placed on other side of lens so that the object coincides with its image. Find the distance of mirror from lens if mirror is convex.

asked Feb 12, 2014 by meena.p

1 answer

An object is placed at a distance of 10 cm to left on axis of a convex lens A of focal length 20 cm.Another convex lens of focal length 10 cm is placed co-axially to the right of the lens A at a distance of 5 cm from A. Find the magnification of final image

asked Feb 12, 2014 by meena.p

1 answer

A glass convex lens of refractive index $\large\frac{3}{2}$ has got a focal length equal to $50 \;cm$ Find the focal length of lens if it is immersed in ethyl alcohol of $refractive index \;1.36$

asked Feb 12, 2014 by meena.p

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A parallel beam of light travelling in water $(\mu =\large\frac{4}{3})$ is refracted through a spherical air bubble of radius R .. Find the location of image formed after refraction at two surfaces.

asked Feb 12, 2014 by meena.p

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A prism of crown glass refracting angle of $50^{\circ}$ and mean refractive index $=1.51$ is combined with one flint glass prism of refractive index $=1.65$ to produce no deviation Then the angle of flint glass is

asked Feb 12, 2014 by meena.p

1 answer

The dispersive power of crown and flint glasses are 0.03 and 0.05 respectively . If difference in refractive indices of blue and red colours is 0.014 for crown glass and 0.023 for flint glass . Then the angle of two prisms for a deviation of $10^{\circ}$ (with out dispersion )

asked Feb 12, 2014 by meena.p

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Calculate the dispersive power for crown glass from given data. $\mu_v= 1.523 $ and $\mu_R=1.5145$

asked Feb 12, 2014 by meena.p

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Find the dispersion produced by a thin prism of $18^{\circ}$ having refractive index fro red light $= 1.56$ and for violet light $=1.68$

asked Feb 12, 2014 by meena.p

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What should be the value of refractive index n of a glass rod placed in air, so that the light entering through the flat surface of rod does not cross the curved surface of rod.

asked Feb 12, 2014 by meena.p

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