Question

A geared system possessed a strain energy if 150kJ, later it was converted into a two-rotor system connected by a shaft. The Strain energy of the equivalent system will be _____

(a) 150 kJ

(b) less than 150 kJ

(c) more than 150 kJ

(d) Dependent on the length of the equivalent shaft

This question was posed to me in a national level competition.

The doubt is from Free Torsional Vibrations of a Geared System topic in chapter Torsional Vibrations of Machine Dynamics

Answer 1

Right option is (a) 150 kJ

The explanation is: If the geared system is converted into an equivalent system of rotors connected by a shaft then the Strain energy of the original and the equivalent system must be same.