Refraction of Light at Plane Surface

IMPORTANT

Refraction of Light at Plane Surface: Overview

This Topic covers sub-topics such as Refractive Index of a Glass Slab using a Travelling Microscope, Deviation in Refraction, Refraction from Plane Surface, Apparent Depth for More than One Liquids and, Apparent Depth for One Liquid

Important Questions on Refraction of Light at Plane Surface

EASY
IMPORTANT

A parallel sided block of glass of refractive index 1.5 which is 3.6 mm thick rests on the floor of a tank which is filled with water (refractive index=43). The difference between the apparent depth of floor at A and B when seen from vertically above is equal to

EASY
IMPORTANT

A bird is flying 3 m above the surface of water. If the bird is diving vertically down with speed = 6 m/s, his apparent velocity as seen by a stationary fish underwater is:

MEDIUM
IMPORTANT

A point object is placed at a distance of 25 cm from a convex lens of focal length 20 cm. If a glass slab of thickness t and refractive index 1.5 is inserted between the lens and object. The image is formed at infinity. Find the thickness t.

HARD
IMPORTANT

A diverging beam of light from a point source S  having divergence angle   α , falls symmetrically on a glass slab as shown. The angles of incidence of the two extreme rays are equal. If the thickness of the glass slab is t and the refractive index n, then the divergence angle of the emergent beam is

EASY
IMPORTANT

Consider a ray of light passing through a rectangular slab of refractive index μ(μ>1) and thickness h as shown below.

This leads to a parallel shift d in the path of the ray, which varies between 0 to dmax as θ varies. How does dmax change with μ ?

MEDIUM
IMPORTANT

When a beam of light goes from a denser medium μd to a rarer medium μr, then it is generally observed that the magnitude of the angle of incidence is half that of the angle of refraction. Then the magnitude of incident angle will be- (here μ=μdμr

EASY
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The angle of deviation produced by the glass slab is

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For a certain parallel-sided glass block, the value of sin isin r is 1.50. A ray of light passes through the block and emerges at an angle of 60° to the surface of the block. What is the value of the angle marked X?

MEDIUM
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What should be the angle of incidence at A of the spherical glass placed in air so that so that grazing emergence of light ray takes place at B?

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Consider the situation shown in figure. Water μw=4/3 is filled in a beaker upto a height of 10 cm. A plane mirror is fixed at a height of 5 cm from the surface of water. Distance of image from the mirror after reflection from it of an object O at the bottom of the beaker is :-

EASY
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In the figure shown the angle made by the light ray with the normal in the medium of refractive index 2 is :-

EASY
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A tank is filled with water to a height of 12.0 cm. The apparent depth of a coin placed at the bottom is measured by a microscope to be 9.0 cm. What is the refractive index of water? If water is replaced by a liquid of refractive index 2 up to the same height, then by what distance would the focus of microscope has to be shifted to see the coin again?

EASY
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The optical density of turpentine is higher than that of water while its mass density is lower. Figure shows a laycr of turpcntine floating over water in a container. For which one of the four rays incident on turpentine in figure, the path. shown is correct

EASY
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A glass slab of thickness 4 cm contains the same number of waves as in x cm of water column when both are traversed by the same monochromatic light. If the refractive indices of glass and water for that light are 53 and 43 respectively, the value of x will be

EASY
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A fish and a bird are moving as shown in figure. Find the velocity of bird as observed by fish.

MEDIUM
IMPORTANT

The apparent depth of needle lying at the bottom of the tank which is filled with water to a height of 15.5 cm is measured by a microscope to be 8.5 cm. If water is replaced by a liquid of refractive index 1.94 to the same height as earlier, compute the displacement of the microscope needed to establish focus on the needle again.

MEDIUM
IMPORTANT

If light is refracted from a plane surface while passing from a denser medium to rarer medium, then which of the following statements is/are correct about it. [C is critical angle]

HARD
IMPORTANT

A ray of light passes through four transparent media whose surfaces are parallel to each other with refractive indices μ 1  ,  μ 2  ,  μ 3  and  μ 4  . If the emergent ray,CD is parallel to the incident ray AB, then, which of the following relations should be correct?

MEDIUM
IMPORTANT

A ray of light is incident on a surface of glass slab at an angle 45°.The angle of refraction if the lateral shift produced per unit thickness is13m 

MEDIUM
IMPORTANT

Three immiscible liquids of densities d1>d2>d3 and refractive indices μ1>μ2>μ3 are put in a beaker. The height of each liquid column is h/3. A dot is made at the bottom of the beaker. For near normal vision, find the apparent depth of the dot.