Answer:
θ = 28.9°
Explanation:
We are given;
Wavelength; λ = 602nm = 602 x 10^(-9) m
Lines per centimetre = 7000 /cm = 700000 /m
Thus, the distance between 2 adjacent lines is;
d = 1/700000 = 1.43 x 10^(-6) m
The angle at which diffracted light is formed is given by the formula
mλ = d sinθ
Where;
m is the mth order of the diffraction
λ is the wavelength of the incident light
d is the distance separating the centres of 2 adjacent slits
θ is the angle at which diffraction occurs
From the question, m is 1 because it says first order.
Thus, plugging in the relevant values into mλ = d sinθ, we have;
1 x 602 x 10^(-9) = 1.43 x 10^(-6) sinθ
sinθ = 602 x 10^(-9)/(1.43 x 10^(-6))
sinθ = 0.42098
θ = sin^(-1) 0.42098
θ = 28.9°
