A laser beam (λ = 694 nm) is incident on two slits 0.100 mm apart. Approximately how far apart (in m) will the bright interference fringes be on the screen 5.00 m from the double slits?

Question

Quizplus · Accepted Answer

The distance between adjacent bright fringes on a screen in a double-slit experiment is given by the equation d sinθ = mλ, where d is the distance between the slit centers, θ is the angle between the incident beam and the fringe, m is the order of the fringe, and λ is the wavelength of the light. In this case, we can assume that the incident beam is perpendicular to the screen, so sinθ = (y/L), where y is the distance from the central maximum to the fringe, and L is the distance from the double slits to the screen. Solving for y, we get y = mλL/d. For the first-order fringe (m = 1), we have y = (694 nm)(5.00 m)/(0.100 mm) = 34.7 mm, or 3.47 × 10^(-2) m. The distance between adjacent fringes is twice this value, or 6.94 × 10^(-2) m. Therefore, the answer is B (3.47 × 10^(-2) m or 3.47 × 10^(-²) ).

A Laser Beam (λ = 694 Nm) Is Incident on Two