Machine Design
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 = [(1 - μ tanθ)/ (1 + μ tanθ)]n
T₁/T₂ = μθ × n
T₁/T₂ = [(1 + μ tanθ)/ (1 - μ tanθ)]n
T₁/T₂ = (μθ)n

ANSWER DOWNLOAD EXAMIANS APP

Machine Design
The cracks in helical springs used in railway carriages usually start on the inner side of the coil because of the fact that

It is subjected to a higher cyclic loading than the outer side
It has a lower curvature than the outer side
It is subjected to a higher stress than the outer side
It is more stretched than the outer side during the manufacturing process

ANSWER DOWNLOAD EXAMIANS APP