Using the expression 2 d sin θ = λ , one calculates the values of d by measuring the corresponding angle θ in the range 0 to 90 ° . The wavelength λ is exactly known and the error in θ is constant for all the values of θ . As θ increases from 0 ° ,

Step-by-step solution

2 d  sin  θ = λ d = λ 2 sin  θ Differentiate on both the sides, ∂ d = λ 2 ∂  cosec  θ ∂ d = λ 2 - cosec  θ  cot  θ ∂ θ ∂ d = - λ  cos   θ 2  sin 2  θ ∂ θ  θ = increases and λ   cos   θ 2   sin 2   θ decreases. Alternate solution d = λ 2 sin  θ ℓ n   d = ℓ n   λ