Question

Oscar Q1. An object is placed at a distance of 30cm in front of a concave mirror of focal length of 10cm; calculate the distance of the image from the mirror, what will be the nature of image?​

Answer 1

• Object distance=u=-30cm
• Focal length=f=10cm
• Image distance=v=?

Using mirror formula

$\boxed{\sf \dfrac{1}{v}-\dfrac{1}{u}=\dfrac{1}{f}}$

$\\ \sf\longmapsto \dfrac{1}{v}=\dfrac{1}{f}+\dfrac{1}{u}$

$\\ \sf\longmapsto \dfrac{1}{v}=\dfrac{1}{10}-\dfrac{1}{30}$

$\\ \sf\longmapsto \dfrac{1}{v}=\dfrac{3-1}{30}$

$\\ \sf\longmapsto \dfrac{1}{v}=\dfrac{2}{30}$

$\\ \sf\longmapsto v=\dfrac{30}{2}$

$\\ \sf\longmapsto v=15cm$