A Young's double-slit apparatus is set up. A screen is positioned 1.16 m from the double slits, and the spacing between the two slits is 0.0500 mm. The distance between alternating bright fringes is 1.42 cm. What is the light source wavelength? (1 nm = 10 ^- ⁹ m)

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Quizplus · Accepted Answer

The distance between alternating bright fringes is given by:$$d = \frac{\lambda D}{s}$$where:* d is the distance between alternating bright fringes* λ is the wavelength of light* D is the distance between the double slits and the screen* s is the spacing between the two slitsSolving for λ, we get:$$\lambda = \frac{ds}{D}$$Plugging in the given values, we get:$$\lambda = \frac{(1.42 	imes 10^{-2} 	ext{ m})(5.00 	imes 10^{-5} 	ext{ m})}{1.16 	ext{ m}} = 6.12 	imes 10^{-7} 	ext{ m} = 612 	ext{ nm}$$Therefore, the correct answer is A.

A Young's Double-Slit Apparatus Is Set Up