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NEET UG PHYSICS MCQ: RAY OPTICS

1 Easy

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Application +4 | -1

The image produced by a concave mirror is one quarter the size of object. If the object is moved

5 \mathrm{~cm}

closer to the mirror, the image will only be half the size of the object. The focal length of mirror is:

View answer and explanation

Correct option: B

f=2.5 \mathrm{~cm}

Option B (

f=2.5 \mathrm{~cm}

) is correct because it is derived by solving the mirror formula for two different object distances and image magnifications.

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An object 5 cm tall is placed

\mathrm{1}\,\,\mathrm{m}

from a concave spherical mirror which has a radius of curvature of

\mathrm{20}\,\,\,\mathrm{cm}

. The size of the image is Red colour is used for danger signals because A ray of light is incident on the hypotenuse of a right-angled prism after travelling parallel to the base inside the prism. If

\mathrm{\mu }

is the refractive index of the material of the prism, the maximum value of the base angle for which light is totally reflected from the hypotenuse is Statement-A: The minimum distance between an object and its real image formed by a convex lens is

2{f}

.

Statement-B: The distance between an object and its real image is minimum when its magnification is -1. Assertion: We cannot produce a real image by plane or convex mirrors under any circumstances.
Reason: The focal length of a convex mirror is always taken negative. If both the object and image are at infinite distance from a refracting telescope its magnifying power will be equal to