A torque T is applied at the free end of a stepped rod of circular cross-sections as shown in the figure. The shear modulus of the material of the rod is G. The expression for d to produce an angular twist θ at the free end is
1
\({\left( {\frac{{32TL}}{{\pi \theta G}}} \right)^{\frac{1}{4}}}\)
2
\({\left( {\frac{{18TL}}{{\pi \theta G}}} \right)^{\frac{1}{4}}}\)
3
\({\left( {\frac{{16TL}}{{\pi \theta G}}} \right)^{\frac{1}{4}}}\)
4
\({\left( {\frac{{2TL}}{{\pi \theta G}}} \right)^{\frac{1}{4}}}\)