Light of wavelength 578.0 nm is incident on a narrow slit. The diffraction pattern is viewed on a screen 62.5 cm from the slit. The distance on the screen between the third order minimum and the central maximum is 1.35 cm . What is the width a of the slit in micrometers (μm)?

Respuesta :

Answer:

[tex]80.6\mu m[/tex]

Explanation:

When light passes through a narrow slit, it produces a diffraction pattern on a distant screen, consisting of several bright fringes (constructive interference) alternated with dark fringes (destructive interference).

The formula to calculate the position of the m-th maximum in the diffraction pattern produced in the screen is:

[tex]y=\frac{m\lambda D}{d}[/tex]

where

y is the distance of the m-th maximum from the central maximum (m = 0)

[tex]\lambda[/tex] is the wavelength of light used

D is the distance of the screen from the slit

d is the width of the slit

In this problem, we have:

[tex]\lambda=578.0 nm = 578\cdot 10^{-9} m[/tex] is the wavelength

D = 62.5 cm = 0.625 m is the distance of the screen

We know that the distance between the third order maximum (m=3) and the central maximum is 1.35 cm (0.0135 m), which means that

[tex]y_3 = 0.0135 m[/tex]

For

m = 3

Therefore, rearranging the equation for d, we find the width of the slit:

[tex]d=\frac{m\lambda D}{y_3}=\frac{(3)(578\cdot 10^{-9})(0.625)}{0.0135}=80.3\cdot 10^{-6} m=80.6\mu m[/tex]

The width a of the slit will be "80.6 μm". To understand the calculation, check below.

Distance and Wavelength

According to the question,

Light's wavelength, λ = 578.0 nm

Screen's distance, D = 62.5 or,

                                   = 0.625 m

Third order maximum, m = 3

Central maximum = 1.35 cm or,

                               = 0.0135 m

We know the relation,

→ y = [tex]\frac{m \lambda D}{d}[/tex]

or,

Width, d = [tex]\frac{m \lambda D}{y_3}[/tex]

By substituting the values,

                 = [tex]\frac{3\times 578.10^{-9}\times 0.625}{0.0135}[/tex]

                 = 80.3 × 10⁻⁶ m or,

                 = 80.6 μm    

Thus the above answer is correct.

Find out more information about wavelength here:

https://brainly.com/question/21630569