MCQOPTIONS
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MCQOPTIONS
This section includes 16 Mcqs, each offering curated multiple-choice questions to sharpen your Machine Dynamics knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
The natural frequency of a spring-mass system on earth is ωn. The natural frequency of this system on the moon (gmoon = gearth/6) is |
| A. | ωn |
| B. | 0.408ωn |
| C. | 0.204ωn |
| D. | 0.167ωn |
| Answer» B. 0.408ωn | |
| 2. |
While calculating the natural frequency of a spring-mass system, the effect of the mass of the spring is accounted for by adding X times its value to the mass, where X is |
| A. | 1/2 |
| B. | 1/3 |
| C. | 1/4 |
| D. | 3/4 |
| Answer» C. 1/4 | |
| 3. |
In vibration isolation system, if ω/ωn < 2, then for all values of damping factor, the transmissibility will be |
| A. | less than unity |
| B. | equal to unity |
| C. | greater than unity |
| D. | zero |
| Answer» D. zero | |
| 4. |
In vibration isolation system, if ω/ωn, then the phase difference between the transmitted force and the disturbing force is |
| A. | 0° |
| B. | 90° |
| C. | 180° |
| D. | 270° |
| Answer» D. 270° | |
| 5. |
CRITICAL_SPEED_IS_EXPRESSED_AS?$ |
| A. | rotation of shaft in degrees |
| B. | rotation of shaft in radians |
| C. | rotation of shaft in minutes |
| D. | natural frequency of the shaft |
| Answer» E. | |
| 6. |
The natural frequency of a spring-mass system on earth is ωn. The natural frequency of this system on the moon (gmoon = gearth/6) is$# |
| A. | ω<sub>n</sub> |
| B. | 0.408ω<sub>n</sub> |
| C. | 0.204ω<sub>n</sub> |
| D. | 0.167ω<sub>n</sub> |
| Answer» B. 0.408‚âà√¨‚àö¬¢<sub>n</sub> | |
| 7. |
The_first_critical_speed_of_an_automobile_running_on_a_sinusoidal_road_is_calculated_by_(modeling_it_as_a_single_degree_of_freedom_system)$ |
| A. | Resonance |
| B. | Approximation |
| C. | Superposition |
| D. | Rayleigh quotient |
| Answer» B. Approximation | |
| 8. |
For an under damped harmonic oscillator, resonance |
| A. | occurs when excitation frequency is greater than undamped natural frequency |
| B. | occurs when excitation frequency is less than undamped natural frequency |
| C. | occurs when excitation frequency is equal to undamped natural frequency |
| D. | never occurs |
| Answer» D. never occurs | |
| 9. |
A_vehicle_suspension_system_consists_of_a_spring_and_a_damper._The_stiffness_of_the_spring_is_3.6_kN/m_and_the_damping_constant_of_the_damper_is_400_Ns/m._If_the_mass_is_50_kg,_then_the_damping_factor_(d_)_and_damped_natural_frequency_(fn),_respectively,_are |
| A. | 0.471 and 1.19 Hz |
| B. | 0.471 and 7.48 Hz |
| C. | 0.666 and 1.35 Hz |
| D. | 0.666 and 8.50 Hz |
| Answer» B. 0.471 and 7.48 Hz | |
| 10. |
While calculating the natural frequency of a spring-mass system, the effect of the mass of the spring is accounted for by adding X times its value to the mass, where X i? |
| A. | 1/2 |
| B. | 1/3 |
| C. | 1/4 |
| D. | 3/4 |
| Answer» C. 1/4 | |
| 11. |
The accelerometer is used as a transducer to measure earthquake in Richter scale. Its design is based on the principle that |
| A. | its natural frequency is very low in comparison to the frequency of vibration |
| B. | its natural frequency is very high in comparison to the frequency of vibration |
| C. | its natural frequency is equal to the frequency of vibration |
| D. | measurement of vibratory motion is without any reference point |
| Answer» D. measurement of vibratory motion is without any reference point | |
| 12. |
In vibration isolation system, if ω/ωn < 2, then for all values of damping factor, the transmissibility will be$ |
| A. | less than unity |
| B. | equal to unity |
| C. | greater than unity |
| D. | zero |
| Answer» D. zero | |
| 13. |
In steady state forced vibrations, the amplitude of vibrations at resonance is _____________ damping coefficient. |
| A. | equal to |
| B. | directly proportional to |
| C. | inversely proportional to |
| D. | independent of |
| Answer» D. independent of | |
| 14. |
The critical speed of a shaft with a disc supported in between is equal to the natural frequency of the system in |
| A. | transverse vibrations |
| B. | torsional vibrations |
| C. | longitudinal vibrations |
| D. | none of the mentioned |
| Answer» B. torsional vibrations | |
| 15. |
When a body is subjected to transverse vibrations, the stress induced in a body will be |
| A. | shear stress |
| B. | bending stress |
| C. | tensile stress |
| D. | compressive stress |
| Answer» C. tensile stress | |
| 16. |
In vibration isolation system, if ω/ωn, then the phase difference between the transmitted force and the disturbing force is |
| A. | 0° |
| B. | 90° |
| C. | 180° |
| D. | 270° |
| Answer» D. 270¬¨¬®‚Äö√†√ª | |