Q. A short sighted person can see distinctly only those objects which lie between $10\ cm$ and $100\ cm$ from him. The power of the spectacle lens required to see a distant object is
A) $+ 0.5\ D$
B) $- 1.0\ D$
C) $- 10\ D$
D) $+ 4.0\ D$
Explanation
(b) $f = - d = - 100\ cm = - 1\ m$
$\therefore P = \frac{1}{f} = \frac{1}{- 1} = - 1\ D$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.