Question

Monochromatic light falls on two very narrow slits 0.044 mm apart. Successive fringes on a screen 6.50 m away are 8.1 cm apart near the center of the pattern. Part A) Determine the wavelength of the light. Express your answer to two significant figures and include the appropriate units Part B) Determine the frequency of the light Express your answer to two significant figures and include the appropriate units ?

Answer 1

Answer:

A) λ = 548 nm.

B ) 5.474 x 10¹⁴ Hz.

Explanation:

Distance between two slits ( d ) =.044 x 10⁻³

Distance of screen ( D ) = 6.5 m

Fringe width is given by the expression

Fringe width = λ D /d

where λ is wave length of light .

Given fringe width = 8.1 cm

Putting the values in the equation , we have

8.1 x 10⁻² = λ x 6.5 / .044 x 10⁻³

$\lambda = \frac{8.1\times10^{-2}\times.044\times10^{-3}}{6.5}$

λ = 548 nm.

Frequency of light = velocity of light / wavelength

3 x 10⁸ / 548 x 10⁻⁹

= 5.474 x 10¹⁴ Hz.