Question

Rohit placed a pencil perpendicular to principal axis in front of a converging mirror of focal length 30 cm. The image formed is twice the size of the pencil. Calculate the distance of the object

from the mirror​

Answer 1

$\huge\mathbf{\mid{\overline{\underline{\fbox{\color{red}{Answer}}}\mid}}}$

$magnefication = \frac{ h_{i}}{ h_{0} }$

ᴡᴇ ᴄᴀɴ ᴀssᴜᴍᴇ ɪᴛ ᴛᴏ ʙᴇ ᴠɪʀᴛᴜᴀʟ ʙᴇᴄᴀᴜsᴇ ɪɴ ᴀ ᴄᴏɴᴄᴀᴠᴇ ᴍɪʀʀᴏʀ ɪᴛ ɪs ᴇɴʟᴀʀɢᴇᴅ ᴏɴʟʏ ᴡʜᴇɴ ɪᴛ ɪs ᴠɪʀᴛᴜᴀʟ.

$\frac{ - v}{u} = 2 \\ v = - 24$

ᴍɪʀʀᴏʀ ᴇǫᴜᴀᴛɪᴏɴ

$\frac{1}{v} + \frac{1}{u} = \frac{1}{f} \\ \frac{1}{ - 24 } + \frac{1}{u} = \frac{1}{f} \\ u = - 15cm$

Answer 2

Mirror reflection =15 cm..

HOPE IT WILL HELP YOU.