A concave mirror for face viewing has focal length of 0.4 m. The distance at which you hold the mirror from your face in order to see your image upright with a magnification of 5 is :

  • Option 1)

     0.24\: m

  • Option 2)

    1.60\: m

  • Option 3)

    0.32\: m

  • Option 4)

     0.16\: m

Answers (1)

\frac{1}{v}-\frac{1}{u}=\frac{1}{f} \: \: \:\; \Rightarrow \frac{1}{v}=\frac{1}{f}+\frac{1}{u}

m=\frac{v}{u}

\frac{1}{m}=\frac{u}{v}

\frac{1}{m}=u\left [ \frac{1}{f}+\frac{1}{u} \right ]

\frac{1}{m}=\frac{u}{f}+1

u=f\left ( 1-\frac{1}{m} \right )

u=f\left ( 1-\frac{1}{m} \right )

u=\left ( 0.4 \right )\left ( 1-\frac{1}{5} \right )

u=\left ( 0.4 \right )\left ( .8 \right )

u=.32\; m

 

 


Option 1)

 0.24\: m

Option 2)

1.60\: m

Option 3)

0.32\: m

Option 4)

 0.16\: m

Preparation Products

Knockout JEE Main April 2021

An exhaustive E-learning program for the complete preparation of JEE Main..

₹ 22999/- ₹ 14999/-
Buy Now
Knockout JEE Main April 2022

An exhaustive E-learning program for the complete preparation of JEE Main..

₹ 34999/- ₹ 24999/-
Buy Now
Test Series JEE Main April 2021

Take chapter-wise, subject-wise and Complete syllabus mock tests and get in depth analysis of your test..

₹ 6999/- ₹ 4999/-
Buy Now
JEE Main Rank Booster 2021

This course will help student to be better prepared and study in the right direction for JEE Main..

₹ 13999/- ₹ 9999/-
Buy Now
Test Series JEE Main April 2022

Take chapter-wise, subject-wise and Complete syllabus mock tests and get an in-depth analysis of your test..

₹ 6999/-
Buy Now
Boost your Preparation for JEE Main 2021 with Personlized Coaching
 
Exams
Articles
Questions