Question

. A concave lens has focal length of 20 cm. At what distance from the lens a 5 cm tall object be placed so that it forms an image at 15 cm from the lens? Also calculate the size of the image formed. [Delhi]​

Answer 1

Answer:

Focal length- (-20cm)

distance object-5cm

image distance-15cm

1/f=1/u-1/v

1/ (-20) = 1/5 -1/15

1/(-20)=2/15

1/(-20)×15/2

-150

Explanation:

magnification-(-150)× 5

= -750

real, inverted and inlarged