A ray of light wavelength λ 0 and frequency v 0 enters a glass slab of refractive index μ from air. Then,

Δ λ = λ 0 1 μ - 1 and Δ v ⁡ = 0

Its wavelength increases, frequency decreases

Its wavelength increases, frequency remains same

Match the corresponding entries of column 1 with column 2. [Where m is the magnification produced by the mirror] Column 1 Column 2 (A) m = - 2 (a) Convex mirror (B) m = - 1 2 (b) Concave mirror (C) m = + 2 (c) Real image (D) m = + 1 2 (d) Virtual image

A → b and c; B → b and c; C → b and d; D → a and d

A → a and c; B → a and d; C → a and b; D → c and d

A → a and d; B → b and c; C → b and d; D → b and c

A → c and d; B → b and d; C → b and c; D → a and d

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An object is approaching towards a moving concave mirror of focal length $20 cm$ as shown. The velocity of image formed by mirror w.r.t. object is

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Important Questions on Ray Optics

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Physics>Optics>Ray Optics>Reflection and Refraction at Plane and Spherical Surfaces

You are asked to design a shaving mirror assuming that a person keeps it at

10 cm

from his face and views the magnified image of the face at the closest comfortable distance of

25 cm

. The radius of curvature of the mirror would then be:

MEDIUM

Physics>Optics>Ray Optics>Reflection and Refraction at Plane and Spherical Surfaces

A point source of light, $S$ is placed at a distance $L$ in front of the center of plane mirror of width $d$ which is hanging vertically on a wall. A man walks in front of the mirror along a line parallel to the mirror, at a distance $2 L$ as shown below. The distance over which the man can see the image of the light source in the mirror is:

Question Image

MEDIUM

Physics>Optics>Ray Optics>Reflection and Refraction at Plane and Spherical Surfaces

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 \times 1 0^{8} m s^{- 1}

, the focal length of the lens is:

HARD

Physics>Optics>Ray Optics>Reflection and Refraction at Plane and Spherical Surfaces

The image of an object, formed by a plano - convex lens at a distance of

8 m

behind the lens, is real and is one-third the size of the object. The wavelength of light inside the lens is

\frac{2}{3}

times the wavelength in free space. The radius of the curved surface of the lens is

HARD

Physics>Optics>Ray Optics>Reflection and Refraction at Plane and Spherical Surfaces

A plano-convex lens is made of a material of refractive index n. When a small object is placed 30 cm away in front of the curved surface of the lens, an image of double the size of the object is produced. Due to reflection from the convex surface of the lens, another faint image is observed at a distance of 10 cm away from the lens. Which of the following statement(s) is (are) true?

EASY

Physics>Optics>Ray Optics>Reflection and Refraction at Plane and Spherical Surfaces

When the same monochromatic ray of light travels through glass slab and through water, the number of waves in glass slab of thickness

6 cm

is same as in water column of height

7 cm

. If refractive index of glass is

1.5

then refractive index of water is

HARD

Physics>Optics>Ray Optics>Reflection and Refraction at Plane and Spherical Surfaces

A wire is bent in the shape of a right angled triangle and is placed in front of a concave mirror of focal length

f

, as shown in the figure. Which of the figures shown in the four options qualitatively represent(s) the shape of the image of the bent wire? (These figures are not to scale.)
Question Image

MEDIUM

Physics>Optics>Ray Optics>Reflection and Refraction at Plane and Spherical Surfaces

Two identical glass rods

S_{1}

and

S_{2}

(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

S_{1}

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

S_{2}

. The distance

d

HARD

Physics>Optics>Ray Optics>Reflection and Refraction at Plane and Spherical Surfaces

A transparent slab of thickness

d

has a refractive index

n (z)

that increases with

z

. Here

z

is the vertical distance inside the slab, measured from the top. The slab is placed between two media with uniform refractive indices

n_{1} and n_{2} (> n_{1}),

as shown in the figure. A ray of light is incident with angle

θ_{i}

from medium 1 and emerges in medium 2 with refraction angle

θ_{f}

with a lateral displacement

l

. Which of the following statement(s) is (are) true?
Question Image

HARD

Physics>Optics>Ray Optics>Reflection and Refraction at Plane and Spherical Surfaces

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

Physics>Optics>Ray Optics>Reflection and Refraction at Plane and Spherical Surfaces

A ray of light, travelling in the direction

\frac{1}{2} (\hat{i} + \sqrt{3} \hat{j})

, is incident on a plane mirror. After reflection, it travels along the direction

\frac{1}{2} (\hat{i} - \sqrt{3} \hat{j})

. The angle of incidence is

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Physics>Optics>Ray Optics>Reflection and Refraction at Plane and Spherical Surfaces

A ray of light wavelength

λ_{0}

and frequency v₀ enters a glass slab of refractive index

μ

from air. Then,

MEDIUM

Physics>Optics>Ray Optics>Reflection and Refraction at Plane and Spherical Surfaces

Let the refractive index of a denser medium with respect to rarer medium be

n_{12}

and its critical angle be

θ_{C}

. At an angle of incidence

A

when light is travelling from denser medium to rarer medium, a part of the light is reflected and the rest is refracted and the angle between reflected and refracted rays is

90^{o}

. Angle

A

is given by

EASY

Physics>Optics>Ray Optics>Reflection and Refraction at Plane and Spherical Surfaces

An air bubble in a glass slab with refractive index

1.5

(near-normal incidence) is

5 cm

deep when viewed from one surface and

3 cm

deep when viewed from the opposite face. The thickness (in

cm

) of the slab is

EASY

Physics>Optics>Ray Optics>Reflection and Refraction at Plane and Spherical Surfaces

A beam of light from a source

L

is incident normally on a plane mirror fixed at a certain distance

x

from the source. The beam is reflected back as a spot on a scale placed just above the source

L

. When the mirror is rotated through a small angle

θ

, the spot of the light is found to move through a distance

y

on the scale. The angle

θ

is given by

HARD

Physics>Optics>Ray Optics>Reflection and Refraction at Plane and Spherical Surfaces

A transparent thin film of uniform thickness and refractive index $n_{1} = 1.4$ is coated on the convex spherical surface of radius R at one end of a long solid glass cylinder of refractive index $n_{2} = 1.5$ , 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

Question Image

HARD

Physics>Optics>Ray Optics>Reflection and Refraction at Plane and Spherical Surfaces

A hemispherical glass body of radius 10 cm and refractive index 1.5 is silvered on its curved surface. A small air bubble is 6 cm below the flat surface inside it along the axis. The position of the image of the air bubble made by the mirror is seen :

Question Image

MEDIUM

Physics>Optics>Ray Optics>Reflection and Refraction at Plane and Spherical Surfaces

A light wave is incident normally on a glass slab of refractive index

1.5 .

4 %

of light gets reflected and the amplitude of the electric field of the incident light is

30 \frac{V}{m},

then the amplitude of the electric field for the wave propagating in the glass medium will be:

MEDIUM

Physics>Optics>Ray Optics>Reflection and Refraction at Plane and Spherical Surfaces

Match the corresponding entries of column 1 with column 2. [Where m is the magnification produced by the mirror]

	Column 1		Column 2
(A)	$m = - 2$	(a)	Convex mirror
(B)	$m = - \frac{1}{2}$	(b)	Concave mirror
(C)	$m = + 2$	(c)	Real image
(D)	$m = + \frac{1}{2}$	(d)	Virtual image

HARD

Physics>Optics>Ray Optics>Reflection and Refraction at Plane and Spherical Surfaces

An object is gradually moving away from the focal point of a concave mirror along the axis of the mirror. The graphical representation of the magnitude of linear magnification

(m)

versus distance of the object from the mirror

(x)

is correctly given by
(Graphs are drawn schematically and are not to scale)

An object is approaching towards a moving concave mirror of focal length 20 cm as shown. The velocity of image formed by mirror w.r.t. object is

Important Questions on Ray Optics

Learn and Prepare for any exam you want !

An object is approaching towards a moving concave mirror of focal length $20 cm$ as shown. The velocity of image formed by mirror w.r.t. object is