Description : _______ torsional vibrations will occur in a two-rotor system only if both rotors have the same frequency. (A) Free (B) Forced (C) Unbalanced (D) None of the above
Last Answer : (A) Free
Description : Which of the following statements is/are true? A. Torsional vibrations do not occur in a three rotor system, if rotors rotate in same direction B. Shaft vibrates with maximum frequency when rotors ... C. Zero node behavior is observed in rotors rotating in opposite direction D. All of the above
Last Answer : A. Torsional vibrations do not occur in a three rotor system, if rotors rotate in same direction
Description : Which of the following statements is/are true? A) Torsional vibrations do not occur in a three rotor system, if rotors rotate in same direction B) Shaft vibrates with maximum frequency when rotors ... C) Zero node behavior is observed in rotors rotating in opposite direction D) All of the above
Last Answer : A) Torsional vibrations do not occur in a three rotor system, if rotors rotate in same direction
Description : Which of the following statements is/are true? a. Torsional vibrations do not occur in a three rotor system, if rotors rotate in same direction b. Shaft vibrates with maximum frequency when rotors ... c. Zero node behavior is observed in rotors rotating in opposite direction d. All of the above
Last Answer : a. Torsional vibrations do not occur in a three rotor system, if rotors rotate in same direction
Description : In a two-rotor system, torsional vibration occurs only if the rotors are moving in the ______ direction. (A) same (B) opposite (C) either same or opposite (D) none of the above
Last Answer : (B) opposite
Description : In a two-rotor system, torsional vibration occurs only if the rotors are moving in the ______ direction. A. same B. opposite C. either same or opposite D. none of the above
Last Answer : B. opposite
Description : Free torsional vibrations of a single motor system increases with increase in polar moment of inertia. a) True b) False
Last Answer : b) False
Description : 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
Last Answer : A Transverse vibrations
Description : 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
Last Answer : a) transverse vibrations
Description : There are n rotors mounted on the shaft and when subjected to torsional vibration there will be A. N nodes B. (N-1) nodes C. (N+1) nodesD. Any number of nodes
Last Answer : B. (N-1) nodes
Description : If the polar moment of inertia is increased to four times, then what will be the effect on free torsional vibrations of a single motor system? A. Increases 4 times B. Increases 2 times C. Decreases 4 times D. Decreases 2 times
Last Answer : B. Increases 2 times
Description : f the length inertia is decreased to nine times, then what will be the effect on free torsional vibrations of a single motor system? a) Increases 3 times b) Increases 9 times c) Decreases 9 times d) Decreases 3 times
Last Answer : a) Increases 3 times
Description : Calculate the free torsional vibrations of a single motor system from the following data: C = 8 GN/m 2 , L=9m, I = 600 Kg-m 2 , J = 8×10 4 m 4 a) 162,132 b) 172,132 c) 182,132 d) 192,132
Last Answer : b) 172,132
Description : If the mass moment of inertia is increased to four times, then what will be the effect on free torsional vibrations of a single motor system? a) Increases 4 times b) Increases 2 times c) Decreases 4 times d) Decreases 2 times
Last Answer : d) Decreases 2 times
Description : If the polar moment of inertia is increased to four times, then what will be the effect on free torsional vibrations of a single motor system? a) Increases 4 times b) Increases 2 times c) Decreases 4 times d) Decreases 2 times
Last Answer : b) Increases 2 times
Description : Which of the following relation is correct regarding free torsional vibrations of a single motor system? a) Independent of modulus of rigidity b) Independent of polar moment of inertia c) Dependent on mass moment of inertia d) Independent of length of shaft
Last Answer : c) Dependent on mass moment of inertia
Description : If the mass increases, then the frequency of the free vibrations increases. a) True b) False
Description : Which of the following is a type of free vibration? A Longitudinal vibrations B Transverse vibrations C Torsional vibrations D A, B and C
Last Answer : D A, B and C
Description : Which of the following is a type of free vibration? A. Longitudinal vibrations B. Transverse vibrations C. Torsional vibrations D. A, B and C
Last Answer : D. A, B and C
Description : Which of the following is a type of free vibration? ( A ) Longitudinal vibrations ( C ) Torsional vibrations D ( B ) Transverse vibrations ( D ) A, B and C
Last Answer : ( D ) A, B and C
Description : For the same dimensions of a beam, transverse vibrations have a lower frequency than longitudinal frequency.a) True b) False
Last Answer : a) True
Description : Centrifugal absorber is used to reduce A) Centrifugal force in rotating system B) Torsional vibration of rotating system C) Vibration in linear system D) Transverse vibrations
Last Answer : B) Torsional vibration of rotating system
Description : When the particles of the shaft or disc move in a circle about the axis of the shaft, then the vibrations are known as ___________ . A Longitudinal vibrations B Transverse vibrations C Torsional vibrations D None of these
Last Answer : C Torsional vibrations
Description : The vibrations perpendicular to the shaft axis are known as A Transverse B Longitudinal C Torsional D None of the mentioned
Last Answer : A Transverse
Description : When the particles of the shaft or disc move in a circle about the axis of the shaft, then the vibrations are known as ___________ . A. longitudinal vibrations B. transverse vibrations C. torsional vibrations D. none of these
Last Answer : C. torsional vibrations
Description : During transverse vibrations, shaft is subjected to which type of stresses? A) Tensile stresses B) Torsional shear stress C) Bending stresses D) All of the above
Last Answer : C) Bending stresses
Description : Which type of vibrations are also known as transient vibrations? A) Undamped vibrations B) Damped vibrations C) Torsional vibrations D) Transverse vibrations
Last Answer : B) Damped vibrations
Description : During transverse vibrations, shaft is subjected to which type of stresses? a. Tensile stresses b. Torsional shear stress c. Bending stresses d. All of the above
Last Answer : c. Bending stresses
Description : Which of the following vibrations are classified according to magnitude of actuating force? a. Torsional vibrations b. Deterministic vibrationsc. Transverse d. All of the above
Last Answer : b. Deterministic
Description : Which type of vibrations are also known as transient vibrations? a. Undamped b. Damped c. Torsional d. Transverse vibrations
Last Answer : b. Damped
Description : f radius of gyration increases then the torsional free vibration increases. a) True b) False
Description : What is meant by critical damping coefficient? * 1 point (A) Frequency of damped free vibrations is less than zero (B). The motion is a periodic in nature (C). Both a. and b. (D). None of the above
Last Answer : (C). Both a. and b.
Description : What is meant by critical damping coefficient? A Frequency of damped free vibrations is less than zero B The motion is aperiodic in nature C Both a. and b. D None of the above
Last Answer : B The motion is aperiodic in nature
Description : In damped free vibrations, which parameters indicate vibrations? A) Natural frequency B) Rate of decay of amplitude C) Both a. and b. D) None of the above
Last Answer : C) Both a. and b.
Description : What is meant by critical damping coefficient? B ( A )Frequency of damped free vibrations is less than zero ( B )The motion is aperiodic in nature ( C )Both a. and b. (D)None of the above
Last Answer : ( B )The motion is aperiodic in nature
Description : What is meant by critical damping coefficient? a. Frequency of damped free vibrations is less than zero b. The motion is aperiodic in nature c. Both a. and b. d. None of the above
Last Answer : b. The motion is aperiodic in nature
Description : In damped free vibrations, which parameters indicate vibrations? a. Natural frequency b. Rate of decay of amplitude c. Both a. and b. d. None of the above
Last Answer : c. Both a. and b.
Description : The natural frequency (in Hz) of free longitudinal vibrations is equal to a) Square root (k/m) / (2π) b) Square root (g/δ) / (2π) c) 0.4985/δ d) all of the mentioned
Last Answer : d) all of the mentioned
Description : A body of mass 20 kg is suspended from a spring which deflects 20mm under this load. Calculate the frequency of free vibrations in Hz. a) 3.5 b) 5 c) 6 d) 7
Last Answer : a) 3.5
Description : A cantilever shaft having 50 mm diameter and a length of 300 mm has a disc of mass 100 kg at its free end. The Young’s modulus for the shaft material is 200 GN/m 2 . Determine the frequency of transverse vibrations of the shaft. a) 31 b) 35 c) 37 d) 41
Last Answer : d) 41
Description : f the mass is of 10 Kg, find the natural frequency in Hz of the free longitudinal vibrations. The displacement is 0.01mm. a) 44.14 b) 49.85 c) 43.43 d) 46.34
Last Answer : b) 49.85
Description : Find the displacement in mm of the free longitudinal vibrations if the Natural frequency is 20 Hz. a) 0.1 b) 0.2 c) 0.5 d) 0.6
Last Answer : d) 0.6
Description : Find the displacement in mm of the free longitudinal vibrations if the Natural frequency is 15 Hz. a) 1.1 b) 1.2 c) 1.5 d) 1.6
Last Answer : a) 1.1
Description : Find the natural frequency in Hz of the free longitudinal vibrations if the displacement is 2mm. a) 11.14 b) 12.38 c) 11.43 d) 11.34
Last Answer : a) 11.14
Description : The natural frequency (in Hz) of free longitudinal vibrations is equal to a) 1/2π√s/m b) 1/2π√g/δ c) 0.4985/δ d) all of the mentioned
Description : In damped vibrations, the amplitude of the resulting vibration gradually diminishes. a) True b) False
Description : When heavy rotating masses are connected by a shaft and equal and opposite torques are applied to these masses (rotors) A. The rotors vibrate torsionally in the same direction. B. The rotors vibrate torsionally ... on the axis of shaft which remains undisturbed by vibration. D. Both (B) and (C)
Last Answer : D. Both (B) and (C)
Description : Critical speed of shaft and disc system A) Is equal to natural frequency of the system in transverse vibration B) Is equal to natural frequency of the system in torsional vibration C) Is ... of the system in longitudinal vibration D) Bears no relationship to any of the system natural frequency
Last Answer : A) Is equal to natural frequency of the system in transverse vibration
Description : Which type of frequency measuring instrument has multiple reeds of different natural frequency to measure vibrations? A. Fullarton tachometer B. Frahm Tachometer C. Both A. and B. D. None of the above
Last Answer : B. Frahm Tachometer