Question

a candle flame is kept 1.5m in front of a wall. distance of a spherical mirror of focal length 1m from the candle flame such that an image of the flame is formed on the wall is

Answer 1

Answer:

Given height of the flame  h1=1.5cm

f=-12cm         u=18cm

Using the mirror formula

1/f=1/u+1/v

1/v=1/f-1/v

  1/v=1/-12 +1/18

1/v   =-18+12/18*12

1/v=-1/36

v=-36cm (image distance)

m=-v/u

m=-(-36)/18

m=-2

so the image formed is real inverted and enlarged

height of the image  m=h2/h1 (h1-- height of the object    h2-- height of the image)

    -2=h2/1.5

h2=3cm

 so the image height is 3cm and the negative sign indicates that the image is formed below the principal axis