Concept: The torsion equation is given by: JT=RI¨„=LGθ Where, T is the torque applied, J = polar moment of inertia, Ï„ = shear strength of material, G = modulus of rigidity, θ = angular deflection of shaft (in radians). JT=rI¨„ T=rτJ=rτ×32πd4=16πτd3 Calculation: Ï„ = 48 N/cm2, d = 3 cm T=16πτd3=16π×48×33=81π Ncm