Question

a three times demnished image is formed when it is placed in front of a convex mirror of focal length 15 cm . find the object distance and image distance.​

Answer 1

Answer:

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,

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

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

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

 =10v=50-5v

=15v=50

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

​  

so the image distance (v) =3.33cm.

Explanation: