Question

an object of 4cm high is placed at a distance of 6cm in front of a concave mirror of focal length 18cm. find the position , nature and size of the image

Answer 1

Answer:

Explanation:f=-12cm

u=-6cm

h=4cm

By mirror formula,

1/f=1/v+1/u

1/v=1/f-1/u

=1/-12 +1/6

=-1/12+1/6

=1/12

v=12cm

since object is placed between P and F , we get virtual and erect

m=-v/u

=-12/-6

=+2

also m=h/h

2=h/4cm

h=8cm

hence image is magnified , that is 8cm height. which is our required answer.