A rod of length 10 ~cm lies along the principal axis of a concave mirror of focal length 10 ~cm in such a way that its end closer to the pole is 20 ~cm away from the mirror. The length of the image is

Step-by-step solution

By mirror formula, image distance of A 1 v + 1 u = 1 f aligned 1 v_A + 1 u & = 1 f 1 v_A + 1 (-30) & = 1 -10 v_A & =-15 ~cm aligned Also image distance of C v_C=-20 ~cm The length of image = |v_A-v_C | =|-15-(-20)| =5 ~cm