Recent questions tagged refraction-at-spherical-surfaces-and-lenses

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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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

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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 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 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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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 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 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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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 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

1 answer

Equi convex lens is placed such that optic axis coincides with the x-axis, position of object is $(-40 \;cm, 1 \;cm) $ and position of image $(50 \;cm, -2\;cm) $ where is the lens located

asked Jan 24, 2014 by meena.p

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A double convex lens $(\mu =1.5) $ has its focal length 10 cm. What will be its focal length if it is immersed in liquid of $(\mu_1=\large\frac{4}{3})$

asked Jan 23, 2014 by meena.p

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A point object is placed in front of a thin lens of focal length $f= 0.50\;m$ at a distance of $1.0\;m$ . A flat mirror is placed 2 m behind the lens. What is the distance between the lens and the final image formed.

asked Jan 22, 2014 by meena.p

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Two thin lenses of focal lengths $f_1$ and $f_2$are in contact , the equivalent focal length is

asked Jan 22, 2014 by meena.p

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A parallel beam of light is incident on a solid transparent sphere of refractive inbox $\mu$. If a point image is formed on the back of the sphere , the refractive index of sphere is

asked Jan 22, 2014 by meena.p

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The equiconvex lens of glass of $\mu =1.5$ and focal length $15\;cm$ is silvered on one side. It will behave like.

asked Jan 22, 2014 by meena.p

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A system consists of a convex lens and a concave mirror placed at a distance of x from the lens. Focal length $f_1$ of convex lens in 10 cm and focal length $f_2$ of mirror is 60 cm. If an object is placed at a distance 20 cm from the lens and it is found that the final image coincides with the object position, then what must be the distance 'x'

asked Jan 22, 2014 by meena.p

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An object is kept at a distance of 12 cm from a thin lens and image formed is real. If the object is kept at a distance of $8\;cm$ from the same lens image formed is virtual. If the size of image formed is equal length of lens will be :

asked Jan 22, 2014 by meena.p

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A system of lenses is formed by fitting a plans convex lens, whose radius of curvature is R and $\mu_1$,the refractive index of plano convex lens is $\large\frac{3}{2} $ and $\mu_2$ the refractive index of Plano concave lens is $\large\frac{4}{3}$. Then the focal length of combination is

asked Jan 22, 2014 by meena.p

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A convex lens of focal length 20 cm is placed glass slab of refractive index $\large\frac{3}{2}$.A parallel beam of light is incident on the convex lens. The light will converge.

asked Jan 22, 2014 by meena.p

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A doubled convex lens of refractive index $\mu$ is kept inside two immiscible liquids of refractive inclines $\mu_1$ and $\mu_2$. as shown $\mu_2 < \mu < \mu _1$ , A parallel beam of light is incident on the lens. After refraction on the lens we will get,

asked Jan 20, 2014 by meena.p

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A lens made of material of refractive index $\mu =\large\frac{3}{2} $ when placed in air behaves as shown in figure (1) . But when placed in a medium of refractive index $\mu_s$ it behaves as shown in figure (2) . Then the value of $\mu_s $ is

asked Jan 20, 2014 by meena.p

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Plane surface of plane - convex lens is silvered and it then acts like a concave mirror of focal length . 30 cm. If the refractive index of the lens is 1.5 , the radius of curvature of convex surface is

asked Jan 20, 2014 by meena.p

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A convex lens of focal length 40 cm is kept in contact with a concave lens of focal length 25 cm. What is power of this combined lens system.

asked Jan 17, 2014 by meena.p

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A combination of lens is formed by keeping two identical equiconvex lens of focal length f kept in contact and the space between them filled with liquid of refractive index $\mu_2 =\large\frac{4}{3}$. Focal length of the combination is

asked Jan 16, 2014 by meena.p

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