Question

An object of size 7 cm is placed at a distance of 27 cm in front of a concave

mirror of focal length 18 cm. Find position, nature and size of image formed​

Answer 1

Answer:

Thus,we should place a screen at a distance of 54 cm on the same side as of object as to get sharp image. Thus,the height of image is 14cm and is inverted at a distance of 54cm for sharp image formation.

Explanation:

TO FIND:

The nature and size of image formed also the distance from which mirror should be placed fro sharp image

GIVEN:

Object size=7cm

Object distance[U]=27cm

Focal length of concave mirror[f]=18cm

Let V be the image distance

So by mirror formula we know that;

1/f=1/V+1/U

1/(-18)=1/V+1/(-27)

1/V=1/(-18)+1/27

1/V= (-3+2)/54

1/V= -1/54

V=-54cm

Thus,we should place a screen at a distance of 54 cm on the same side as of object as to get sharp image.

The magnification is shown by:

m=-V/U

m=-(-54)/-27

m= -2

Magnification of image will be |2| and - shows the inverted nature of image

m is also stated as

m= height of image/height of object

-2= height of image/7

height of image= -14cm

Thus,the height of image is 14cm and is inverted at a distance of 54cm for sharp image formation.