Question

Light of wavelength 633 nm from a He-Ne laser passes through a circular aperture and is observed on a screen 4.0 m behind the aperture. The diameter of the central bright area is 5.4 cm. What is the diameter of the aperture?

Answer 1

The answer is "
`1.144 * 10^(-4) \ m`".

Step-by-step explanation:

`w=(2.44 \lambda L)/(D)\\\\D=(2.44 \lambda L)/(w)\\\\`

`=(2.44 * 633 * 10^(-9)* 4 )/(0.054)\\\\=(6178.08* 10^(-9))/(0.054)\\\\=1.144 * 10^(-4) \ m`