Question

The image of an object placed 3.2 cm from a convex
mirror has a transverse magnification of +0.4. Find:

(a) the location of the image
(b) the focal length.​

Answer 1

Answer:

(a) behind the mirror (virtual and erect)

(b) 5.33 cm

Explanation:

(a) first we will find out the distance of object by :-

magnification formula I.e. m = -v/u

+0.4 = -3.2/u

u = -8 cm

so by this we can confirm that the image will be virtual and erect and it will be behind the mirror .

(b) by mirror formula :-

1/v + 1/u = 1/f

so by putting the values

1/3.2 + 1/-8 = 1/f

f = 5.33 cm - (ans)

Answer 2

Answer:

Magnification =-v/u

0.4=-3.2/u

u=-3.2/0.4

u=-8cm

b)1/f=1/v+1/u

=1/3.2-1/8

=2.5-1/8

=1.5/8

f =5.34cm

a) The position of the image is between pole and principal focus