A person has been using spectacles of power $-1.0$ dioptre for distant vision and a separate reading glass of power $2.0$ dioptres. What is the least distance of distinct vision for this person :
Solution
<p>u = 25 cm</p>
<p>$f=\frac{1}{2}$ m = 50 cm</p>
<p>${1 \over v} - {1 \over u} = {1 \over f}$</p>
<p>$\Rightarrow {1 \over v} + {1 \over {25}} = - {1 \over {50}}$</p>
<p>${1 \over v} = - {1 \over {50}}$</p>
<p>$\Rightarrow u = - 50$ cm</p>
About this question
Subject: Physics · Chapter: Optics · Topic: Reflection and Mirrors
This question is part of PrepWiser's free JEE Main question bank. 197 more solved questions on Optics are available — start with the harder ones if your accuracy is >70%.