Question

HØLa ^^

An object forms a virtual image which is 1/8th of the size of the object. If the object is placed at a distance of 40cm from the convex mirror, calculate :

▶The position of the image
▶the focal length of the convex mirror


✔Solve clearly


Thanks ✌

Answer 1

Ask for doubt in comments section below.

Answer 2

Given, m =1/8. u = -40 cm

Now we know , m = -v/u

1/8 = - v/-(40)

1/8 = v/40

thus v = +5 cm , Here positive sign indicates that image is formed at a distance 5 cm behind the mirror.

Now from mirror formula,

1/v+1/u=1/f

⇒1/5+1/−40=1/f

⇒8−1/40=1/f

⇒f=40/7 cm

Hence focal length = 5.71 cm