Answer:
2.481 mm
Explanation:
Given that
Distance between the slits, d = 0.275 mm = 2.75*10^-4 m
Wavelength of the lamp, λ = 546.1 nm
Distance between slit and the screen, L = 1.25 m
To solve this question, we would be applying the formula for Young's double slit fringes, from the path difference equal to a whole number of wavelengths.
mλ = dy/L
The question states that we should find the distance from the centre to the 1st order bright fringe, thus, m = 1
Now, we apply all these values into the question
1 * 546.1*10^-9 = (2.75*10^-4 * y) / 1.25
1.25 * 1 * 546.1*10^-9 = 2.75*10^-4 * y
6.825*10^-7 = 2.75*10^-4 * y
y = 6.825*10^-7 / 2.75*10^-4
y = 0.002481 m or 2.481 mm
