First order X-ray reflection (λ = 154 pm) is maximum from a set of (2, 0, 0) planes of a B.C.C lattice was observed at 16∘, 6’. Then, the edge length of unit cell is
560 pm
For, first order reflection, n = 1
λ=2d sinθ, d=λ2 sin θ=1542×0.2773=280pmd(2, 0, 0)=154√22+02+02⇒a=2×280=560 pm