Question

an object is placed at a distance of 10 cm from a concave mirror of focal length 20cm draw the ray diagram for the formation of image calculate the image distance state two characteristics of image formed

Answer 1

see diagram as shown in figure, here you can see position of object , position of image and and complete ray diagram.

given, focal length of concave mirror, f = -20 cm
distance of object from the mirror, u = -10 cm

use formula, 1/v + 1/u = 1/f

or, 1/v = 1/f - 1/u

or, 1/v = 1/-20 - 1/-10

or, 1/v = -1/20 + 1/10 = 1/20

or, v = +20cm

hence, image position is 20cm right side from the pole of concave mirror as shown in diagram.

Answer 2

Answer:

Explanation:

ocal length of concave mirror, f = -20 cm

distance of object from the mirror, u = -10 cm

use formula, 1/v + 1/u = 1/f

or, 1/v = 1/f - 1/u

or, 1/v = 1/-20 - 1/-10

or, 1/v = -1/20 + 1/10 = 1/20

or, v = +20cm

hence, image position is 20cm right side from the pole of concave mirror