Question

An object 2 cm in size is placed 30 cm in front of a concave mirror of focal length 15 cm. At what distance from the mirror should a screen be placed in order to obtain a sharp image? What will be the nature and the size of the image formed?
3 points
30cm, virtual and erect
-30cm, virtual and erect
-20cm, real and inverted
-30cm, real and inverted

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Answer 1

Answer:

The screen should be placed 30cm in front of the mirror to obtain the real image. So the image formed is at the same position, real, same size, but inverted.

Answer 2

Explanation:

f = 15 cm

h = 2 cm

u = -30 cm

using,

1/f = 1/v+1/u, we get

1/v = 1/f - 1/u

= 1/-15 - 1/-30

= 2-1/-30

= 1/-30

v = -30

so,the screen should be placed at a distance of 30cm on the same side of the object in order to obtain a sharp image.

Hope you will understand it...