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# An object 5 cm is placed at a distance of 20 cm in front of a convex mirror of radius of curvature 30 cm. Find the position, nature and size of the image. - CBSE Class 10 - Science

ConceptRefraction of Light Image Formation in Lenses Using Ray Diagrams - Convex Lens

#### Question

An object 5 cm is placed at a distance of 20 cm in front of a convex mirror of radius of curvature 30 cm. Find the position, nature and size of the image.

#### Solution

Object distance, u= – 20 cm
Object height, h= 5 cm
Radius of curvature, R= 30 cm
Radius of curvature = 2 × Focal length
R= 2f
f= 15 cm
According to the mirror formula,

1/v-1/u=1/f

1/v=1/f-1/u

=1/15+1/20=(4+3)/60=7/60

The positive value of v indicates that the image is formed behind the mirror.

Magnificatiom m="Image Distance"/"Object Distance"=-8.57/(-20)=0.428

The positive value of magnification indicates that the image formed is virtual

Magnificatiom m="Height of image"/"Height of Object"=(h')/h

h'=m x h=0.428 x 5=2.14 cm

The positive value of image height indicates that the image formed is erect.
Therefore, the image formed is virtual, erect, and smaller in size.

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#### APPEARS IN

NCERT Solution for Science Textbook for Class 10 (2014 to Current)
Chapter 10: Light - Reflection and Refraction
Q: 14 | Page no. 186
Solution An object 5 cm is placed at a distance of 20 cm in front of a convex mirror of radius of curvature 30 cm. Find the position, nature and size of the image. Concept: Refraction of Light - Image Formation in Lenses Using Ray Diagrams - Convex Lens.
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