question_answer

     Two heavy rotating masses are connected by shafts of length \[{{l}_{1}},{{l}_{2}}\] and \[{{l}_{3}}\] and the corresponding diameters are island (/3.This system is reduced to a torsionally equivalent system having uniform diameter \[{{d}_{1}}\] of the shaft. The equivalent length of the shaft is equal to:

A) \[{{l}_{1}}+{{l}_{2}}+{{l}_{3}}\]

B) \[\frac{{{l}_{1}}+{{l}_{2}}+{{l}_{3}}}{3}\]

C) \[{{l}_{1}}+{{l}_{2}}{{\left( \frac{{{d}_{1}}}{{{d}_{2}}} \right)}^{3}}+{{l}_{3}}{{\left( \frac{{{d}_{1}}}{{{d}_{3}}} \right)}^{3}}\]

D) \[{{l}_{1}}+{{l}_{2}}{{\left( \frac{{{d}_{1}}}{{{d}_{2}}} \right)}^{4}}+{{l}_{3}}{{\left( \frac{{{d}_{1}}}{{{d}_{3}}} \right)}^{4}}\]