Question

An object is placed at a distance of 10 cm from a convex mirror of focal length 5 cm.
(i) Draw a ray-diagram showing the formation of image.
(ii) State two characteristics of the image formed.
(iii) Calculate the distance of the image from mirror.

Answer 1

Object Distance(u) = 10 cm. (negative)
Focal length of the lens (f) = 5 cm.
We know, convex mirror always forms the virtual, upright and diminished.Also, Object distance in the convex mirror is always negative where as Image distance and focal length are positive.

Now, Applying the Mirror's Formula,

$\frac{1}{f}$ =$\frac{1}{v}$ +$\frac{1}{u}$

= $\frac{1}{5}$ =$\frac{1}{v}$ +$\frac{1}{}$

=$\frac{1}{5}$ =$\frac{(10-v)}{10v}$

$10v=50-5v$

$15v=50$

v=$\frac{10}{3}$

so the image distance (v) =3.33cm.