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The phenomenon involved in the reflection of radio-waves by ionosphere is similar to

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Important Questions on Optics

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General Science>Physics>Optics>Total Internal Reflection and Critical Angle

Pick the wrong answer in the context with rainbow.

MEDIUM

General Science>Physics>Optics>Total Internal Reflection and Critical Angle

A diver looking up through the water sees the outside world contained in a circular horizon. The refractive index of water is

\frac{4}{3}

, and the diver's eyes are

15 cm

below the surface of the water. Then the radius of the circle is :

HARD

General Science>Physics>Optics>Total Internal Reflection and Critical Angle

A point source S is placed at the bottom of a transparent block of height 10 mm and refractive index 2.72. It is immersed in a lower refractive index liquid as shown in the figure. It is found that the light emerging from the block to the liquid forms a circular bright spot of diameter 11.54 mm on the top of the block. The refractive index of the liquid is

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MEDIUM

General Science>Physics>Optics>Total Internal Reflection and Critical Angle

The critical angle for light going from medium

x

to medium

y

θ

. The speed of light in medium

x

v_{x}

. The speed of light in medium

y

HARD

General Science>Physics>Optics>Total Internal Reflection and Critical Angle

A ray of light incident parallel to the base

P Q

of an isosceles right - angled triangular prism

P Q R

suffers two successive total internal reflections at the face

P Q

and

Q R

before emerging reversed in direction as shown.
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If the refractive index of the prism is

μ

, then

HARD

General Science>Physics>Optics>Total Internal Reflection and Critical Angle

A transparent cube of side

d

, made of a material of refractive index

μ_{2}

, is immersed in a liquid of refractive index

μ_{1} (μ_{1} < μ_{2})

. A ray is incident on the face

A B

at an angle

θ

(shown in the figure). Total internal reflection takes place at the point

E

on the face

B C .

Then,

θ

must satisfy

MEDIUM

General Science>Physics>Optics>Total Internal Reflection and Critical Angle

A ray of light is incident from a denser to a rarer medium. The critical angle for total internal reflection is

θ_{iC}

and Brewster's angle of incidence is

θ_{iB}

, such that

\frac{sin θ_{iC}}{sin θ_{iB}} = η = 1.28

. The relative refractive index of the two media is

MEDIUM

General Science>Physics>Optics>Total Internal Reflection and Critical Angle

The critical angle for glass is

41 ° 48^{'}

and that for water is

48 ° 36^{^{'}} .

Calculate the critical angle for glass-water interface.

MEDIUM

General Science>Physics>Optics>Total Internal Reflection and Critical Angle

A ray of light incident on a transparent sphere at an angle

\frac{π}{4}

and refracted at an angle

r

, emerges from the sphere after suffering one internal reflection. The total angle of deviation of the ray is

EASY

General Science>Physics>Optics>Total Internal Reflection and Critical Angle

A ray of light originates from inside a glass slab and is incident on its inner surface at an angle $θ$ as shown,

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In this experiment the location $x$ of the spot where they ray hits the screen is recorded. Which of the following correctly shown the plot of variation of $x$ with the angle $θ$ ?

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MEDIUM

General Science>Physics>Optics>Total Internal Reflection and Critical Angle

The critical angle of a medium for a specific wavelength, if the medium has relative permittivity

3

and relative permeability

\frac{4}{3}

for this wavelength, will be:

MEDIUM

General Science>Physics>Optics>Total Internal Reflection and Critical Angle

A green light is incident from the water to the air - water interface at the critical angle

(θ_{c})

. Select the correct statement.

EASY

General Science>Physics>Optics>Total Internal Reflection and Critical Angle

There is a small source of light at some depth below the surface of water (refractive index

= \frac{4}{3}

) in a tank of large cross sectional surface area. Neglecting any reflection from the bottom and absorption by water, percentage of light that emerges out of surface is (nearly):
[Use the fact that surface area of a spherical cap of height

h

and radius of curvature

r

2 π r h

]

EASY

General Science>Physics>Optics>Total Internal Reflection and Critical Angle

In total internal reflection, when the angle of incidence is equal to the critical angle for the pair of media in contact, what will be angle of refraction?

MEDIUM

General Science>Physics>Optics>Total Internal Reflection and Critical Angle

If the critical angle for total internal reflection from a medium to vacuum is

45 °,

then velocity of light in the medium is,

EASY

General Science>Physics>Optics>Total Internal Reflection and Critical Angle

A $45 ° - 90 °$ prism as shown in the figure is immersed in water. A ray of light is incident normally on one of its shorter faces. The minimum index of refraction that the prism must have if this ray is to be totally reflected within the glass at the long face of the glass is (Assume refractive index of water $n_{water} = 1.3$ )

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HARD

General Science>Physics>Optics>Total Internal Reflection and Critical Angle

A point source of light is placed at the bottom of a water lake. If the area of the illuminated circle on the surface is equal to three times the square of the depth of the lake, refractive index of water in the lake is

HARD

General Science>Physics>Optics>Total Internal Reflection and Critical Angle

A ray of light incident on a glass sphere (refractive index

\sqrt{3}

) suffer total internal reflection before emerging out exactly parallel to the incident ray. The angle of incidence was

HARD

General Science>Physics>Optics>Total Internal Reflection and Critical Angle

An isosceles glass prism with base angles

40 °

is champed over a tray of water in a position such that the base is just dipped in water. A ray of light incident normally on the inclined face suffers total internal reflection at the base. If the refractive index of water is

1.33

then the condition imposed on the refractive index,

μ

of the glass is-

HARD

General Science>Physics>Optics>Total Internal Reflection and Critical Angle

A beam of light consisting of red, green and blue colours is incident on a right-angled prism. The refractive index of the material of the prism for the above red, green and blue wavelengths are

1.39

1.44

and

1.47

respectively.

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The prism will:

The phenomenon involved in the reflection of radio-waves by ionosphere is similar to

Important Questions on Optics

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