Description : Which of the following statements is/are true for coulomb damping? 1. Coulomb damping occurs due to friction between two lubricated surfaces2. Damping force is opposite to the direction of motion of vibrating body ... 2, 3 and statement 4 c. Only statement 2 d. All the above statements are true
Last Answer : c. Only statement 2
Description : Which of the following statements are TRUE for damped vibrations? (P) . For a system having critical damping, the value of the damping ratio is unity and system does not undergo a vibratory motion. (Q) . Logarithmic decrement method ... Q only (B) P and S only (C) P, Q and R only (D) Q and S only
Last Answer : (C) P, Q and R only
Description : In which direction does the damping force acts? a) Opposite to the motion b) Along the motion c) Perpendicular to motion d) Variable
Last Answer : a) Opposite to the motion
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 : The equation of motion for a vibrating system with viscous damping is d 2 x/dt 2 + c/m X dx/dt + s/m X x = 0 If the roots of this equation are real, then the system will be A. over damped B. under damped C. critically damped D. none of the mentioned
Last Answer : A. over damped
Description : If frequency of excitation of a forced vibration system with negligible damping is very close to natural frequency of the system, then the system will A) Execute harmonic motion of large amplitude B) Beat with a very high peak amplitude C) Perform aperiodic motion D) None of the above
Last Answer : A) Execute harmonic motion of large amplitude
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 : In coulomb damping, the amplitude of motion in each cycle is reduced by A. F/K B. 2F/K C. 4F/K D. F/4K
Last Answer : C. 4F/K
Description : The motion of particle is represented by, x = Asin(wt) in which A stands for A. Amplitude B. Wavelength C. Frequency D. Damping
Last Answer : A. Amplitude
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 : The equation of motion for a vibrating system with viscous damping is d 2 x/dt 2 + c/m X dx/dt + k/m X x = 0 If the roots of this equation are real, then the system will be a) over damped b) under damped c) critically damped d) none of the mentioned Ans:a
Last Answer : a) over damped
Description : Which of the following is a type of transmitted force to the foundation? (A) Damping force (B) Undamping force (C) Tensile force (D) Torsional force
Last Answer : (A) Damping force
Description : The ratio of the maximum displacement of the forced vibration to the deflection due to the static force, is known as A Damping factor B Damping coefficient C Logarithmic decrement D Magnification factor
Last Answer : D Magnification factor
Description : In a spring-mass system, which of the following force is not considered? A Spring force B Damping force C Accelerating force D A and B
Last Answer : B Damping force
Description : The ratio of the maximum displacement of the forced vibration to the deflection due to the static force is known as A Logarithmic decrement B Magnification factor C Damping factor D None of the mentioned
Last Answer : B Magnification factor
Description : The angle between spring force and damping force is A 180 0 B 120 0 C 90 0 D 0 0
Last Answer : C 90 0
Description : Which of the following is true regarding Ɛ>1? A. Transmitted force is greater than applied force B. Transmitted force is less than applied force C. Spring force is less than applied force D. Damping force is less than applied force
Last Answer : A. Transmitted force is greater than applied force
Description : Calculate damped natural frequency, if a spring mass damper system is subjected to periodic disturbing force of 30 N. Damping coefficient is equal to 0.76 times of critical damping coefficient and undamped natural frequency is 5 rad/sec A. 3.99 rad/sec B. 2.13 rad/sec C. 4.12 rad/sec D. 3.24 rad/sec
Last Answer : D. 3.24 rad/sec
Description : Which of the following relations is true for viscous damping? A) Force α relative displacement B) Force α relative velocity C) Force α (1 / relative velocity) D) None of the above
Last Answer : B) Force α relative velocity
Description : In a spring-mass system, which of the following force is not considered? B ( A ) Spring force ( B ) Damping force ( C ) Accelerating force ( D ) A and B
Last Answer : B ) Damping force
Description : The ratio of maximum displacement of the forced vibration to the deflection due to the static force, is known as A. Damping FactorB. Damping Coefficient C. Logarithmic Decrement D. Magnification Factor
Last Answer : D. Magnification Factor
Description : The angle between spring force and damping force is A. 180 0 B. 90 0 C. 0 0 D. None of the above
Last Answer : B. 90 0
Description : Which of the following relations is true for viscous damping? a. Force α relative displacement b. Force α relative velocity c. Force α (1 / relative velocity) d. None of the above
Last Answer : b. Force α relative velocity
Description : The ratio of the maximum displacement of the forced vibration to the deflection due to the static force, is known as a) Damping factor b) Damping coefficient c) Logarithmic decrement d) Magnification factor
Last Answer : d) Magnification factor
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 : The ratio of the maximum displacement of the forced vibration to the deflection due to the static force is known as (A) damping factor (B) damping coefficient (C) logarithmic decrement (D) magnification factor
Last Answer : (D) magnification factor
Description : Which of the following is true regarding Ɛ>1? a) Transmitted force is greater than applied force b) Transmitted force is less than applied force c) Spring force is less than applied force d) Damping force is less than applied forc
Last Answer : a) Transmitted force is greater than applied force
Description : Which of the following is a type of transmitted force to the foundation? a) Damping force b) Undamping force c) Tensile force d) Torsional force
Last Answer : a) Damping force
Description : The ratio of the maximum displacement of the forced vibration to the deflection due to the static force, is known as a) damping factor b) damping coefficient c) logarithmic decrement d) magnification factor
Last Answer : d) magnification factor
Description : In steady state forced vibrations, the amplitude of vibrations at resonance is __________ damping coefficient. A. Equal to B. Directly proportional to C. Inversely proportional toD. Independent of
Last Answer : C. Inversely proportional to
Description : The advantage of critical damping is A. That vibrating body come to rest in smallest possible time B. There is no vibration C. That amplitude of vibration is maximum D. The amplitude of vibration is minimum
Last Answer : A. That vibrating body come to rest in smallest possible time
Description : The equation of motion for spring mass system includes A. Inertia Force B. Spring Force C. Both D. Gravitational force
Last Answer : C. Both
Description : n which direction does the accelerating force acts? a) Opposite to the motion b) Along the motion c) Perpendicular to motion d) Variable
Last Answer : b) Along the motion
Description : Unit of the damping factor is ______. (A) Nm/s (B) N/sm (C) N/m (D) none of the above
Last Answer : (D) none of the above
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 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
Last Answer : C inversely proportional to
Description : A simple pendulum is found to vibrate at a frequency of 0.5Hz in vacuum and0.45 Hz in a viscous fluid medium. Find the damping factor. 0.5122 (B) 0.9272 (C) 0.4359 (D) 0.2568
Last Answer : (C) 0.4359
Description : A vehicle suspension system consists of a spring and a damper. Stiffness of spring is 3.5 KN/m and damping constant of damper is 400Ns/m. If mass is 50 kg, then damping factor is A 0.606 B 0.10 C 0.666 D 0.471
Last Answer : D 0.471
Description : The ratio of the actual damping coefficient (c) to the critical damping coefficient (cc ) is known as _________ A Damping factor B Damping coefficient C Resistive factor D Resistive coefficient
Last Answer : A Damping factor
Description : Calculate logarithmic decrement if damping factor is 0.33. A 1.36 B 3.23 C 5.16D 2.19
Last Answer : D 2.19
Description : Calculate natural frequency of damped vibration, if damping factor is 0.52 and natural frequency of the system is 30 rad/sec which consists of machine supported on springs and dashpots. A 25.62 rad/sec B 20.78 rad/sec C 14.4 rad/sec D 15.33 rad/sec
Last Answer : A 25.62 rad/sec
Description : Eddy current damping is an example of _____ A Coulomb damping B Hysteresis damping C Viscous damping D Dry friction damping
Last Answer : C Viscous damping
Description : Calculate natural frequency of damped vibration, if damping factor is 0.52 and natural frequency of the system is 30 rad/sec which consists of machine supported on springs and dashpots. A 21 rad/sec B 25.62 rad/sec C 20.22 Hz D 3.15 Hz
Last Answer : B 25.62 rad/sec
Description : A vibrating system having mass 1kg, a spring of stiffness 1000N/m and damping factor of 0.632 and it is put to harmonic excitation of 10N. Find the amplitude at resonance. A 0.079 B 7.9C 0.056 D 0.00791
Last Answer : D 0.00791
Description : A simple pendulum is found to vibrate at a frequency of 0.5Hz in vacuum and 0.45Hz in a viscous fluid medium. Find the damping factor. A 0.5122 B 0.9237 C 0.4359 D 0.2568
Last Answer : C 0.4359
Description : Calculate the value of critical damping coefficient if a vibrating system has mass of 4kg and stiffness of 100N/m A 20 N-sec/m B 40 N-sec/m C 60 N-sec/m D 80 N-sec/m
Last Answer : B 40 N-sec/m
Description : Determine the viscous damping coefficient if damper offers resistance 0.05N at constant velocity 0.04m/sec A 0.8N-sec/m B 1.5N-sec/m C 2.5N-sec/m D 1.25N-sec/m
Last Answer : D 1.25N-sec/m
Description : Calculate logarithmic decrement if damping factor is 0.086 A 0.245 B 0.425 C 0.542 D 0.252
Last Answer : C 0.542