Question

A concave lens of a focal length 15 cm forms an image 10 cm from the lens. how far is the object from the lens.

✳respectively answer ur question ✳

Answer 1

Hello friend your answer is
F=15
v=10
u=?
use concave lens formula
1/v-1/u=1/f
1/u=1/f+1/v
1/u=1/15+1/10
2+3/30
5/30=1/6

Answer 2

hey... MATE !!
here's ur answer,

In this question, we have to calculate the object distance u.

u = ?
image distance, v = -10
focal length, f = -15

use lens formula,

1 / v - 1/ u = 1/ f

1/ -10 - 1 / u = 1/ -15

- 1 / u = -1 / 15 + 1/10

- 1/u. = -2 + 3÷ 30

- 1/ u = 1/ 30

hence u = -30 cm.

thus, the object is placed at a distance of 30 cm from the concave lens.

Hope it might be helpful :) //