Siddharth Jawa
Last Activity: 4 Years ago
dsinθ = mλ (for bright fringe)
sinθ = mλ/d
I = Io(Sinβ/β)^2 where, β=α/2= 2pi x δ/2λ
β = pi *delta / lamda (delta= Asinθ)
β = pi *asinθ / lamda (sinθ= m*lamda/d)
β = pi *a*m*lamda / d*lamda = pi*a*m / d (m=4)
β = 4*pi*a / d
( for intensity = 0 at m=4, β should be an integral multiple of pi)
where,
d= separation of slits ; a= slit width
Therefore,
pi= 4*pi*a/d
d=4a
a/d= 1/4
which implies
a:d = 1:4
