Chapter 9 · Light - Reflection and Refraction

NCERT Class 10 Science Chapter 9 Intext Questions (Page 145)

All 2 questions of NCERT Class 10 Science Chapter 9 Intext Questions (Page 145) — Light - Reflection and Refraction — in the book's order, each with its answer and a step-by-step solution.

1. Q1
   Find the ​focal ​length ​of a ​convex mirror whose radius ​of curvature ​is $32$ ​cm.
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   The focal length is $f=+16\text{cm}$, half the radius of curvature, with the focus behind the convex mirror.

   The focal length is $16$ cm. Since the mirror is convex its principal focus lies behind the reflecting surface, so on the New Cartesian sign convention $f=+16$ cm $=+0.16$ m.

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2. Q2
   A concave mirror produces three times ​magnified (enlarged) real image of an object ​placed at $10$ ​cm ​in ​front of it. Where is the image located?
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   The image is $30$ cm in front of the mirror, real, inverted and three times the size of the object.

   The image is located $30$ cm from the mirror, on the same side as the object — that is, $30$ cm in front of the mirror ($v=-30$ cm). It is real and inverted, and three times the size of the object, so it can be caught on a screen placed there.

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