Q8. The pupil diameter of a human eye is decreased without changing the eye-lens focal length. Which statements are correct? Assume geometrical optics for depth of field, and diffraction-limited resolution for option B.
Select all that apply

Question

Q8. The pupil diameter of a human eye is decreased without changing the eye-lens focal length. Which statements are correct? Assume geometrical optics for depth of field, and diffraction-limited resolution for option B.

Select all that apply

G1 Physics · Accepted Answer

This is MULTIPLE CORRECT. The pupil opening is made smaller; optical power remains unchanged. A: TRUE. Light collected is proportional to pupil area A = πd²/4; smaller d admits less light. B: FALSE. For diffraction-limited resolution, θₘᵢₙ ≈ 1.22λ/d. If pupil diameter d decreases, θₘᵢₙ INCREASES (resolution worsens). C: TRUE. A smaller aperture reduces geometrical blur from defocus, increasing geometrical depth of field. D: TRUE. For the same retinal distance and incoming object angle, geometri…