Question

10.
An object is placed at 100 mm in front of a concave mirror which produces an upright image (erect image). The
radius of curvature of the mirror is:
(a) Less than 100 mm
(b) Between 100 mm and 200 mm
(c) Exactly 200 mm
(d) More than 200 mm​

Answer 1

Answer:

Concave mirror forms erect image when an object is placed between the focus and the pole.

So it's focus much be more than 100. And radius is equal to double of focus.

thus ,

Radius of curvature = 2×100 = 200

(D) More than 200mm

Answer 2

Answer:

The radius of curvature of the mirror is more than 200 mm​ i.e.option(d).

Explanation:

From the question we have,

Object distance from the mirror(u)=100mm

The nature of image =upright i.e.erect

For an image to be upright the object must be placed within the focus(f) of the concave mirror. So,

                                     $f > 100mm$       (1)

The relation between focal length and radius of curvature(R) of the mirror is given as,

                                    $R=2f$                    (2)

By using equation (1) in equation (2) we get;

                                    $R > 200mm$

Hence, the radius of curvature of the mirror is more than 200 mm​ i.e.option(d).