Q. A camera objective has an aperture diameter $d$. If the aperture is reduced to diameter $d/2$, the exposure time under identical conditions of light should be made
A) $\sqrt{2}$ fold
B) 2 fold
C) 2$\sqrt{2}$ fold
D) 4 fold
Explanation
(d) Time of exposure $\propto \frac{1}{(Aperture)^{2}}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.