Q20 of 117 Page 10

An erect image three times the size of the object is formed with a concave mirror of radius of curvature 36 cm. What is the position of the image?

For an erect image, magnification is positive. Thus, m = 3 for an erect image three times the size of the object.
m = 3


For a concave mirror,



⇒v = -3u
Using Mirror formula,

Putting the value of v = -3u


v = -3u
⇒ v = 36 cm
Thus, the image is formed behind the mirror at a distance of 36 cm.

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