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What is the formula for Magnification?

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Important Questions on Ray Optics and Optical Instruments

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Physics>Optics>Ray Optics and Optical Instruments>Reflection at Plane and Spherical Surfaces

A long horizontal mirror is next to a vertical screen (see figure). Parallel light rays are falling on the mirror at an angle $α$ from the vertical. If a vertical object of height $h$ is kept on the mirror at a distance $d > h$ $\tan (α) .$ The length of the shadow of the object on the screen would be.

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Physics>Optics>Ray Optics and Optical Instruments>Reflection at Plane and Spherical Surfaces

The focal length

f

is related to the radius of curvature

r

of the spherical convex mirror by:

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Physics>Optics>Ray Optics and Optical Instruments>Reflection at Plane and Spherical Surfaces

A real, inverted and equal in size image is formed by

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Physics>Optics>Ray Optics and Optical Instruments>Reflection at Plane and Spherical Surfaces

Rays from sun converge at a point

15 cm

in front of concave mirror. Where should the object be placed so that size of its image is equal to the size of the object?

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Physics>Optics>Ray Optics and Optical Instruments>Reflection at Plane and Spherical Surfaces

An object is placed at a distance of

40 cm

in front of a concave mirror of focal length

20 cm

. The image produced is

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Physics>Optics>Ray Optics and Optical Instruments>Reflection at Plane and Spherical Surfaces

An object is kept on the principal axis of a concave mirror of focal length

10 c m

, at a distance of

15 c m

from its pole. The image formed by the mirror is:

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Physics>Optics>Ray Optics and Optical Instruments>Reflection at Plane and Spherical Surfaces

If a parallel beam of light is incident on convex as well as concave mirror then after reflection they pass through focal point. If

f

is the focal length and

R

is the radius of curvature of a mirror then for both the mirrors

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Physics>Optics>Ray Optics and Optical Instruments>Reflection at Plane and Spherical Surfaces

An object is placed at a distance

10 cm

from the convex mirror of focal length

15 cm

. The distance of image from the mirror is :

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Physics>Optics>Ray Optics and Optical Instruments>Reflection at Plane and Spherical Surfaces

For a real object, which of the following can produce a real image?

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Physics>Optics>Ray Optics and Optical Instruments>Reflection at Plane and Spherical Surfaces

An object is placed at the focus of a convex mirror. The image will be at

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Physics>Optics>Ray Optics and Optical Instruments>Reflection at Plane and Spherical Surfaces

An object is placed at a distance of

25 cm

on the axis of a concave mirror having focal length

20 cm

. What will be the lateral magnification of an image?

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Physics>Optics>Ray Optics and Optical Instruments>Reflection 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

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Physics>Optics>Ray Optics and Optical Instruments>Reflection at Plane and Spherical Surfaces

For plane mirror, the value of magnification

m = 1

, then its focal length

f =

_____.

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Physics>Optics>Ray Optics and Optical Instruments>Reflection at Plane and Spherical Surfaces

A person looks at the image of two parallel finite length lines

P Q

and

R S

in a convex mirror (see figure)
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Which of the following represents schematically the image correctly? (Note : letters

P, Q, R

and

S

are used only to denote the endpoints of the lines.)
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Physics>Optics>Ray Optics and Optical Instruments>Reflection at Plane and Spherical Surfaces

A small pencil of length

10 cm

is kept along the axis of a concave mirror of radius of curvature

40 cm

with its tip touching the mirror. The size of pencil' s image would appears to be:

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Physics>Optics>Ray Optics and Optical Instruments>Reflection at Plane and Spherical Surfaces

Four graphs between

\frac{1}{u}

and

\frac{1}{v}

given for spherical mirrors. Which one of them suitable represents a convex mirror, as per the new Cartesian sign convention?

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Physics>Optics>Ray Optics and Optical Instruments>Reflection at Plane and Spherical Surfaces

The object distance

u

, image distance

v

and focal length

f

for a spherical mirror are related as

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Physics>Optics>Ray Optics and Optical Instruments>Reflection at Plane and Spherical Surfaces

A short straight object of height

100 cm

lies before the central axis of a spherical mirror whose focal length has absolute value

|f| = 40 cm

. The image of object produced by the mirror is of height

25 cm

and has the same orientation of the object. One may conclude from the information:

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Physics>Optics>Ray Optics and Optical Instruments>Reflection at Plane and Spherical Surfaces

A concave mirror of focal length

15 cm

, forms an image having twice the linear dimensions of the object. The position of the object, when the image is virtual, will be

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Physics>Optics>Ray Optics and Optical Instruments>Reflection at Plane and Spherical Surfaces

A mirror is placed at an angled of $30 °$ with respect to $y -$ axis (see figure). A light ray travelling in the negative $y -$ direction strikes the mirror. The direction of the reflected ray is given by the vector

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What is the formula for Magnification?

Important Questions on Ray Optics and Optical Instruments

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