Ask Question
25 October, 12:55

Red and blue light are simultaneously passed through a diffraction grating. The first-order maxima for the red light is located 20 cm from middle of the central bright fringe.

Where is the first-order maxima for the blue light located? a) Also at 20 cm from the middle of the central bright fringe. b) Greater than 20 cm from the middle of the central bright fringe. c) Less than 20 cm from the middle of the central bright fringe.

+2
Answers (1)
  1. 25 October, 13:21
    0
    c) True. Less than 20 cm from the middle of the central bright fringe.

    Explanation:

    The diffraction pattern of a grid is given by the expression

    d sin θ = m λ

    Where d is the separation between the slits, λ the wavelength and m the order of spectrum diffraction

    Let's apply this equation to our case

    Red light.

    Its wavelength is in the 700 nm range

    λ₁ = 700 10⁻⁹ m

    sin θ₁ = (m / d) lam1

    For the first diffraction order m = 1

    sin θ₁ = (1 / d) 7 10⁻⁷

    Blue light

    Length wave range 450 nm

    Lam2 = 450 10⁻⁹ m

    sin θ₂ = (1 / d) lam₂

    sin θ₂ = (1 / d) 4.5 10⁻⁷

    Let's divide these two relationships

    sin θ₂ / sin θ₁ = 4.5 10⁻⁷ / 7 10⁻⁷

    sin θ₂ / sin θ₁ = 4.5 / 7

    sin θ₂ = 0.64 sin θ₁

    In diffraction measurements the distance to the screen in general is much greater than the separation of the spectral lines, so the hypotenuse will be considered constant

    sin θ = Y / h

    sin θ₂ = 0.64 sin θ₁

    y₂ / h = 0.64 y₁ / h

    y₂ = 0.64 y₁

    y₂ = 0.64 20

    y₂ = 12.8 cm

    let's review the claims

    a) False

    b) False

    c) True
Know the Answer?
Not Sure About the Answer?
Find an answer to your question 👍 “Red and blue light are simultaneously passed through a diffraction grating. The first-order maxima for the red light is located 20 cm from ...” in 📗 Physics if the answers seem to be not correct or there’s no answer. Try a smart search to find answers to similar questions.
Search for Other Answers