What is the correct answer?

4

# In a band and block brake, the ratio of tensions on tight side and slack side of the band is (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 = μ. θ. n

T₁/T₂ = [(1 - μ tanθ)/(1 + μ tanθ)]n

T₁/T₂ = (μ θ)n

T₁/T₂ = [(1 + μ tanθ)/(1 - μ tanθ)]n