Question

1)rohit focused a image of candle flame
on a white screen​ using convex lens. he noted down the position of the candle, screen and lens under :
position of candle = 26.0 cm
position of convex lens = 50 cm
position of screen = 74.0 cm
i) what is the focal length of the lens?
ii)where will be the image formed if he shift the candle towards lens to 38cm ?

Answer 1

Answer:

(ii) image is formed beyond c

Answer 2

Answer:

( i ) .  Object distance u = 50 - 26 = 24 cm

Image distance v = 74 - 50 = 24 cm .

Since object distance is equal to image distance.

2 f = 24

= > f = 12 cm

So , focal length of object is 12 cm.

( ii ) . u = 50 - 38 = 12 cm

It's mean candle is at focus.

= > Image will form at infinity.

( ii ) Refer to attachment for ray diagram.