Question

Find out the image distance when the object is at a distance of 20cm infront of concave mirror when the focal length is 15cm and also find out the height of the image when height of the object is 2cm.

Answer 1

Answer:

As per conversation u=-20 and f=-15

1/f=1/v+1/u

-1/15=1/v-1/20

1/v=1/20-1/15=-1/60

v=-60

Negative sign shows that image is real and in front of the mirror.

size of image/size of object=v/u=60/20=3

size of image=3×2=6 cm