Question

a concave lens of focal length 15 CM forms an image 10cm from the lens for far is an object placed from the lens draw a ray diagram​

Answer 1

f = 15cm,

u = 10cm,

v =?

1/v = 1/f + 1/u = 1/15 + 1/10

=2+3/30 = 5/30 = 1/6

therefore, v = 6 cm

Answer 2

$f = 15cm,\\v = 10cm,\\u =?\\1/u = 1/f + 1/v = 1/10 + 1/15\\=3+2/30 = 5/30 = 1/6\\therefore, v = 6 cm$