Question

Write answers to the following questions based on the data given in the table -3
1) What changes will come gradully in the size of an image, when we move an object away
from the concave mirror?
2) In which situation inverted images formed by a concave mirror?
3)If the centre of curvature of a concave mirror is 10 cm, where the object should beplaced
to get an image at centere of curvature?​

Answer 1

Answer:

1) The size of the image or height of the image decreases and the image distance increases until it is placed on focus.

When it is placed between focus and pole of mirror, the image becomes virtual.

2) When object is placed between infinity and focus the image formed is real and inverted.

3) Object should be placed 10cm in front of mirror.

Explanation:

1) From table

2) From table

3) If R= 10 cm, i.e, f = 5cm [f =R/2]

We want image at C, i.e,

Image distance from pole, v = 10 cm

so, by mirror formula,

1/f = 1/v + 1/u

Put values with correct sign,

1/(-5) = 1/(-10) + 1/u [f for concave mirror is negative

and image distance will also be

negative as real image will be formed]

1/u = -1/5 +1/10

1/u = (-2 + 1)/10 = -1/10

so u = -10 or the object should be placed 10cm in front of the mirror.