EASY
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What is power of refracting surface

Important Questions on Refraction, Dispersion and Lens

MEDIUM

A parallel beam of light strikes a piece of transparent glass having cross section as shown in the figure below. Correct shape of the emergent wavefront will be (figures are schematic and not drawn to scale)

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EASY
There is a small air bubble at the centre of a solid glass sphere of radius r and refractive index μ. What will be the apparent distance of the bubble from the centre of the sphere, when viewed from outside?
HARD

A beaker of radius r is filled with waterrefractive index 43 up to a height H as shown in the figure on the left. The beaker is kept on a horizontal table rotating with angular speed ω. This makes the water surface curved so that the difference in the height of water level at the centre and at the circumference of the beaker is hhH, hr, as shown in the figure on the right. Take this surface to be approximately spherical with a radius of curvature R. Which of the following is/are correct? (g is the acceleration due to gravity)

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MEDIUM

A light ray enters a solid glass sphere of refractive index μ=3 at an angle of incidence 60°. The ray is both reflected and refracted at the farther surface of the sphere. The angle (in degrees) between the reflected and refracted rays at this surface is:

HARD
The eye can be regarded as a single refracting surface. The radius of curvature of this surface is equal to that of the cornea (7.8 mm). This surface separates two media of refractive indices 1 and 1.34. Calculate the distance from the refracting surface at which a parallel beam of light will come to focus.
HARD

A transparent thin film of uniform thickness and refractive index n1=1.4 is coated on the convex spherical surface of radius R at one end of a long solid glass cylinder of refractive index n2=1.5 , as shown in the figure. Rays of light parallel to the axis of the cylinder traversing through the film from air to glass get focused at distance f1 from the film, while rays of light traversing from glass to air get focused at distance f2 from the film. Then

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MEDIUM
Two identical glass rods S1 and S2 (refractive index = 1.5) have one convex end of radius of curvature 10 cm. They are placed with the curved surfaces at a distance d as shown in the figure, with their axes (shown by the dashed line) aligned. When a point source of light P is placed inside rod S1 on its axis at a distance of 50 cm from the curved face, the light rays emanating from it are found to be parallel to the axis inside S2 . The distance d is

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MEDIUM
Diameter of a plano - convex lens is 6 cm and thickness at the centre is 3 mm. If the speed of light in the material of lens is 2×108 m s-1, the focal length of the lens is:
EASY

A beam of diameter d is incident on a glass hemisphere as shown. If the radius of curvature of the hemisphere is very large in comparison to d, then the diameter of the beam at the base of the hemisphere will be

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HARD
There is a small air bubble at the centre of a solid glass sphere of radius r and refractive index μ . What will be the apparent distance of the bubble from the centre of the sphere, when viewed from outside?
EASY
A concave spherical surface of radius of curvature 10 cm separates two medium x & y 0f refractive index 4/3 & 3/2 respectively. If the object is placed along principal axis in medium X then

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MEDIUM
A ray from air parallel to axis converges at A in glass sphere as depicted in diagram. Refractive index of glass sphere is n3. Find value of n.

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MEDIUM
A ray is incident on a glass sphere as shown. The opposite surface of the sphere is partially silvered. If the net deviation of the ray transmitted at the partially silvered surface is 1/3rd of the net deviation suffered by the ray reflected at the partially silvered surface (after emerging out of the sphere). Find the refractive index of the sphere.

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EASY
A spherical thick shell made of transparent material is cut along its chord as shown. The smaller part will

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MEDIUM
A point objects is placed at the centre of a glass sphere of radius 6 cm and refractive index 1.5. The distance of the virtual image from the surface of the sphere is
HARD
A thin symmetrical double convex lens of refractive index μ2=1.5 is placed between a medium of refractive index μ1=1.4 to the left and another medium of refractive index μ3=1.6 to the right. Then, the system behaves as
EASY
Assertion: A beam of white light enters the curved surface of a semicircular piece of glass along the normal. The incoming beam is moved clockwise (so that angle of incidence increases), the colour of the refracted beam is red before it stops emerging from a flat surface.

Reason: The index of refraction for light at the red end of the visible spectrum is lesser than at the violet end.
MEDIUM
A spherical surface of radius of curvature R, separates air (refractive index 1.0) from glass (refractive index 1.5). The centre of curvature is in the glass. A point object P place in air is found to have a real image Q in the glass. The line PQ cuts the surface at a point O and PQ=OQ. The distance PO is equal to :
MEDIUM

For a optical arrangement shown in the figure. Find the position and nature of images

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MEDIUM
Parallel rays of light are falling on convex spherical surface of radius of curvature R=20 cm as shown. Refractive index of the medium is μ=1.5. After refraction from the spherical surface parallel rays