How to Calculate Distance Between Interference Fringes
What is the formula to calculate the distance between adjacent bright interference fringes on a screen?
Given a setup with two slits 0.100 mm apart, located 1.20 m from the viewing screen, and light of wavelength 500 nm falling on the slits, how do we determine how far apart adjacent bright interference fringes will be on the screen?
Answer:
The adjacent bright interference fringes on the screen will be approximately 6.00 mm (or 6.00 x 10⁻³ m) apart.
The distance between adjacent bright interference fringes can be calculated using the formula: Δy = (λ * D) / d, where Δy is the distance between adjacent fringes, λ is the wavelength of light, D is the distance between the screen and the slits, and d is the distance between the slits.
In this case, the given values are: - Distance between slits (d) = 0.100 mm (0.100 x 10⁻³ m) - Wavelength of light (λ) = 500 nm (500 x 10⁻⁹ m) - Distance between screen and slits (D) = 1.20 m Substitute these values into the formula: Δy = ((500 x 10⁻⁹ m) * (1.20 m)) / (0.100 x 10⁻³ m), Δy = (6 x 10⁻⁷ m) / (1 x 10⁻⁴ m), Δy = 6 x 10⁻⁷ / 1 x 10⁻⁴, Δy = 6 x 10⁻⁷ * 10⁴ / 1, Δy = 6 x 10⁻³ m. Therefore, the adjacent bright interference fringes will be approximately 6.00 mm (or 6.00 x 10⁻³ m) apart on the screen.