Question

list four characteristic of the image formed by a concave of focal length 20cm when the object is placed at a distance of 40cm from its optical centre. ​

Answer 1

characteristics of image formed by concave lens when kept at C

>virtual

>erect

>diminished

>b/w focal length and optical centre

u = -40cm

f = -20cm

by lens formula

1/v - 1/u = 1/f

1/v = 1/f + 1/u

1/v = 1/-20-1/40

= v = -80/6

=13.33cm