Question

The critical speed of the shaft is affected by the

• A. Diameter and the eccentricity of the shaft
• B. Span and the eccentricity of the shaft
• C. Diameter and the span of the shaft
• D. Frequency of vibrations

Hint:

Critical speed of a shaft depends entirely on its structural stiffness and mass distribution: - Higher diameter ($d \uparrow$) $\implies$ Stiffness ($I \uparrow$) $\implies$ Critical speed $\uparrow$ - Longer span ($L \uparrow$) $\implies$ Stiffness $\downarrow$ $\implies$ Critical speed $\downarrow$ - Eccentricity influences vibration amplitude, but does not alter the critical speed value itself.

Answer 1

The Correct Option is C