Light of wavelength 500 nm illuminates a round 0.50-mm-diameter hole. A screen is placed 6.0 m past the slit. What is the width of the central bright circle on the screen?

Question

Quizplus · Accepted Answer

The width of the central bright circle (central maximum) in a diffraction pattern from a circular aperture is given by the formula $ \theta = 1.22 \frac{\lambda}{D} $, where $ \lambda $ is the wavelength and $ D $ is the diameter of the aperture. The linear width on the screen is $ 2L \tan(\theta) \approx 2L \theta $ for small angles, where $ L $ is the distance to the screen. Substituting the given values, the width is approximately 15 mm.

Light of Wavelength 500 Nm Illuminates a Round 0 3700μm3700 \mu \mathrm { m }3700μm

Light of Wavelength 500 Nm Illuminates a Round 0 $3700 \mu \mathrm { m }$