Question

An object is located 30cm in front of a concave mirror focal length 15cm. Find location of the image and its magnification.

Answer 1

hope this helps you.....

Answer 2

Given:

• Object distance = 30 cm
• Mirror focal length = 15 cm
• Mirror is concave

To find:

Image distance & magnification ?

Calculation:

Applying MIRROR FORMULA (with sign conventions):

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

$\implies \dfrac{1}{ - 15} = \dfrac{1}{v} + \dfrac{1}{ - 30}$

$\implies \dfrac{1}{v} = \dfrac{1}{ 30} - \dfrac{1}{15}$

$\implies \dfrac{1}{v} = \dfrac{1 - 2}{ 30}$

$\implies \dfrac{1}{v} = \dfrac{ - 1}{ 30}$

$\implies \: v = - 30 \: cm$

So, image is 30 cm in front of mirror.

• Magnification = -v/u

$\implies \: mag. = - \dfrac{ - 30}{ -30}$

$\implies \: mag. = - 1$

So, magnification is -1.