Answer: R = 0.131 m
Explanation: The formulae for the distance between a fringe and the first (center) is given by
y = R×mλ/d
Where y = distance between first and nth fringe = 4mm = 4×10^-3m
λ = wavelength of light = 441.1nm = 441.1×10^-9m
R = distance between slits and screen =?
d = distance between slits = 0.29mm = 2.9×10^-4m
4×10^-3 = R ×2 ×441.4×10^-9/ 2.9×10^-5
Hence R = (4×10^-3) ×(2.9×10^-5)/2×441.4×10^-9
R = 1.16 × 10^-7/8.828×10^-7
R = 1.16/8.828
R = 0.131 m
