# In a band and block brake, the ratio of tensions on the tight and slack sides of band is given by (where μ = Coefficient of friction between the blocks and the drum, θ = Semi-angle of each block subtending at the centre of drum, and n = Number of blocks)

T₁/T₂ = μθ × n

T₁/T₂ = (μθ)n

T₁/T₂ = [(1 - μ tanθ)/ (1 + μ tanθ)]n

T₁/T₂ = [(1 + μ tanθ)/ (1 - μ tanθ)]n

Please do not use chat terms. Example: avoid using "grt" instead of "great".