Question

3. Draw a labelled diagram for the formation of image by a convex lens of focal
length 15 cm when the object is placed at a distance of 25 cm from the lens.
Determine the size of the image formed if the size of the object is 4cm. ​

Answer 1

Answer:

thamk you so so so so so so so so so much for the free points

Answer 2

Answer:

given :-

focal length (f) = 15cm

distance of object (u) = - 25cm

distance of image = v

size of object (h) = 4cm

determine:-

the size of image = H

solution :-

we know that;

1/v - 1/u = 1/ f

1/v - (-1/25) = 1/ 15

1/v + 1/25 = 1/15

1/v = 1/15 - 1/25

LCM of 15 and 25 = 75

1/v = (5 - 3)/75

1/v = 2/75

Hence;

v = 75/2

v = 37.5cm

Now ;

v/u = H/h

37.5/ (-25) = H/4

- 1.5 × 4 = H

H = 6cm

( height can't be negative )