Description : Increasing which of the following factor would result in increase of free torsional vibration? A. Radius of gyration B. Mass moment of inertia C. Polar moment of inertia D. Length
Last Answer : C. Polar moment of inertia
Description : Increasing which of the following factor would result in increase of free torsional vibration? a) Radius of gyration b) Mass moment of inertiac) Polar moment of inertia d) Length
Last Answer : c) Polar moment of inertia
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 : 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 : 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 : If the particle of a body vibrate along a circular arc, whose centre lies on the axis of the shaft then the body is said to have A) Transverse vibration B) Longitudinal vibration C) Torsional vibration D) None of the above
Last Answer : C) Torsional vibration
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 : 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 : 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 : The natural frequency of torsional vibration is given by A) ωn = (-kt)/I B) ωn = kt/I C) ωn = √(kt/I) D) ωn = √(2&kt/I)
Last Answer : C) ωn = √(kt/I)
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 : 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 : Free torsional vibrations will occur in a two rotor system only if both rotors have same frequency. a) True b) False
Last Answer : a) True
Description : f the spring displacement is high then the frequency of the spring increases. a) True b) False
Description : Reduction in vibration amplitude after one complete cycle of single degree free vibration with dry friction damping is_____, if where F"= frictional force between mass and surface and k =stiffness of the system. a)4F/k a b) 2f/K C) 3F/k D)8F/k
Last Answer : a)4F/k
Description : When two masses vibrate at the same frequency and in phase, it is called a principal mode of vibration A. True B. False C. Does not depend on vibration D. None of the above
Last Answer : A. True
Description : Maximum displacement due to forced vibration is dependent on deflection due to static force. a) True b) False
Description : In damped vibrations, the amplitude of the resulting vibration gradually diminishes. a) True b) False
Description : If the mass increases, then the frequency of the free vibrations increases. a) True b) False
Description : In under damped vibrating system, the amplitude of vibration ______. (A) decreases linearly with time (B) increases linearly with time (C) decreases exponentially with time (D) increases exponentially with time
Last Answer : (C) decreases exponentially with time
Description : When there is a reduction in amplitude over every cycle of vibration, then the body is said to have A Free vibration B Forced vibration C Damped vibration D None of the mentioned
Last Answer : C Damped vibration
Description : When there is a reduction in amplitude over every cycle of vibration, then the body is said to have ( A ) Free vibration ( B ) Forced vibration ( C ) Damped vibration ( D ) None of the mentioned
Last Answer : ( C ) Damped vibration
Description : When there is a reduction in amplitude over every cycle of vibration, then the body is said to have a) free vibration b) forced vibration c) damped vibrationd) under damped vibration
Last Answer : c) damped vibration
Description : When there is a reduction in amplitude over every cycle of vibration, then the body is said to have a) free vibration b) forced vibration c) damped vibration d) under damped vibration
Description : When there is a reduction in amplitude over every cycle of vibration, then the body is said to have a) free vibration b) forced vibration c) damped vibration d) none of the mentioned
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 : 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 : 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 : 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 : A shaft of diameter d carries two discs at its two ends. The lowest torsional frequency is ω n . If the diameter is doubled, then the lowest torsional frequency becomes A 4ω n B ω n /2 C ω n /4 D 4ω n
Last Answer : D 4ω n
Description : A shaft of length l carries two discs at its two ends. The lowest torsional frequency is ω n . If the shaft length is doubled, then the lowest torsional frequency becomes A ω n /2 B ω n /√2 C √2ω n D 2ω n
Last Answer : B ω n /√2
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 : 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 : Natural frequency of the system is due to A Resonance B Forced Vibration C Damping D Free Vibration
Last Answer : D Free Vibration
Description : Natural frequency of the system is due to A) Free vibration B) Forced vibration C) Resonance D) Damping
Last Answer : A) Free vibration
Description : During free vibration, different degrees of freedom oscillate at different frequencies.
Last Answer : False
Description : During free vibration, different degrees of freedom oscillate with different phase angles.
Description : Which of the following methods will give an incorrect relation of the frequency for free vibration? a) Equilibrium method b) Energy method c) Reyleigh’s method d) Klein’s method
Last Answer : d) Klein’s method
Description : 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°
Last Answer : C 180°
Description : 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
Last Answer : C greater than unity
Description : In the diagram shown below, if rotor X and rotor Z rotate in same direction and rotor Y rotates in opposite direction, then specify the type of node vibration. A. Three node vibration B. Two node vibration C. Single node vibration D. None of the above
Last Answer : B. Two node vibration
Description : In vibration isolation system, if ω/ω n > 1, then the phase difference between the transmitted force and the disturbing force is A. 0° B. 90° C. 180° D. 270°
Last Answer : C. 180°