The angular width of the central maximum in a single slit diffraction pattern is given by Δθ=a2λ
Substituting the given values:
λ=628×10−9 m
a=0.2×10−3 m
Δθ=0.2×10−32×628×10−9 rad
Δθ=6280×10−6 rad =6.28×10−3 rad
To convert radians to degrees, multiply by π180:
Δθ=6.28×10−3×3.14180 degrees
Δθ=2×10−3×180 degrees
Δθ=360×10−3 degrees =36×10−2 degrees
Comparing this with α×10−2 degrees, we get α=36.
Answer: 36