Description : Determine logarithmic decrement, if the amplitude of a vibrating body reduces to 1/6 th in tw cycles. a. 0.223 b. 0.8958 c. 0.3890 d. None of the above
Last Answer : b. 0.8958
Description : When the torsional pendulum vibrating the observed amplitudes on the same side of neutral axis for successive cycles are found to decay 50% of the initial value determine logarithmic decrement. A 0.065 B 0.006 C 0.693 D 0.5
Last Answer : C 0.693
Description : When the torsional pendulum vibrating, the observed amplitudes on the same side of the neutral axis for successive cycles are found to decay 50% of the initial value determine logarithmic decrement. A 0.065 B 0.006 C 0.693 D 0.5
Description : In under damped vibrating system, if x 1 and x 2 are the successive values of the amplitude on the same side of the mean position, then the logarithmic decrement is equal to A x 1 /x 2 B log (x 1 /x 2 ) C loge (x 1 /x 2 ) D log (x 1 .x 2 )
Last Answer : C loge (x 1 /x 2 )
Description : In under damped vibrating system, if x 1 and x 2 are the successive values of the C amplitude on the same side of the mean position, then the logarithmic decrement is equal to ( A ) x 1 /x 2 ( B ) log (x 1 /x 2 ) ( C ) loge (x 1 /x 2 ) ( D ) log (x 1 .x 2 )
Last Answer : ( C ) loge (x 1 /x 2 )
Description : In under damped vibrating system, if x1 and x2 are the successive values of the amplitude on the same side of the mean position, then the logarithmic decrement is equal to a) x1/x2 b) log (x1/x2) c) ln (x1/x2) d) log (x1.x2)
Last Answer : c) ln (x1/x2)
Description : In under damped vibrating system, if x 1 and x 2 are the successive values of the amplitude on the same side of the mean position, then the logarithmic decrement is equal to a) x 1 /x 2 b) log (x 1 /x 2 )c) loge (x 1 /x 2 ) d) log (x 1 .x 2 )
Last Answer : b) log (x 1 /x 2 )
Description : Logarithmic decrement is defined as the ____________ of the amplitude reduction factor. (A) reciprocal (B) logarithm (C) natural logarithm (D) all of the above
Last Answer : (C) natural logarithm
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 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
Description : Calculate logarithmic decrement if damping factor is 0.33. D ( A ) 1.36 ( B ) 3.23 ( C ) 5.16 ( D ) 2.19
Last Answer : D ) 2.19
Description : Calculate logarithmic decrement if damping factor is 0.33. a. 1.36 b. 3.23 c. 5.16 d. 2.19
Last Answer : d. 2.19
Description : find the value of logarithmic decrement of a vibratory system if its natural frequency is 10rad/sec, its mass is 10kg and its damping constant is 100N.s/m a) 36.27 b)362.7 c)0.3627 d)3.627
Last Answer : d)3.627
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 : 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 : 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 rate of decay of oscillations is known as....... A. critical damping B. damping coefficient C. transmissibility D. logarithmic decrement
Last Answer : D. logarithmic decrement
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 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 : 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 : 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 instruments measure the amplitude of a vibrating body? (A) Vibrometers (B) Seismometer (C) Both (a) and (b) (D) None of these
Last Answer : (C) Both (a) and (b)
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 : 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 : 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 : The number of cycles per unit time is called _________ A. Period B. Frequency C. Amplitude D. Wavelength
Last Answer : B. Frequency
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 : In damped vibrations, the amplitude of the resulting vibration gradually reduces. This is due to the reason that an amount of energy is always dissipated to overcome the ________ * 1 point (A) Frictional resistance (B) Work done(C) Fluid pressure (D) Air pressure
Last Answer : (A) Frictional resistance
Description : In damped vibrations, the amplitude of the resulting vibration gradually reduces. This is due to the reason that an amount of energy is always dissipated to overcome the ________ a) Frictional resistance b) Work done c) Fluid pressure d) Air pressure
Last Answer : a) Frictional resistance
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 : A seismometer is a device used to measure the ___________ of a vibrating body. (A) displacement (B) velocity (C) acceleration (D) all of the above
Last Answer : (A) displacement
Description : The reciprocal of the interval of time by a vibrating body to complete a cycle is called A Period B Frequency C Resonance D None of the mentioned
Last Answer : B Frequency
Description : When no external force is acting on the vibrating body, the vibrations are said to be A. Free Vibrations B. Forced Vibrations C. Loaded Vibrations D. Undamped Vibrations
Last Answer : A. Free Vibrations
Description : When the external force is acting on the vibrating body, the vibrations are said to be A. Natural Vibrations B. Forced Vibrations C. Loaded Vibrations D. Undamped Vibrations
Last Answer : B. Forced Vibrations
Description : The instrument that measures the displacement of a vibrating body is called__________ a. seismometer b. transducer c. accelerometer
Last Answer : a. seismometer
Description : The instrument that measures the acceleration of a vibrating body is called___________
Last Answer : Ans- Accelerometer
Description : In vibrometer, the relative motion between the mass and vibrating body is converted into proportional ________. (A) current (B) voltage (C) resistance (D) ampere
Last Answer : (B) voltage
Description : The instruments which are used to measure the ___________ of a vibrating body are called vibration measuring instrument. (A) displacement (B) velocity (C) acceleration (D) all of the above
Last Answer : (D) all of the above
Description : A node means a section where the amplitude of vibration is A. Maximum B. Half of the maximum C. Zero D. 1⁄4 of the maximum
Last Answer : C. Zero
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 : A vibrating machine of 100 kg is mounted on a rubber pad which has stiffness of 500 N/m. Determine force transmitted to the foundation if the unbalanced force 500 N acts on it. The frequency ratio (ω/ω n ) is 1.5 and ξ = 0.5 A. 461.62 N B. 400.23 N C. 450 N D. Insufficient data
Last Answer : A. 461.62 N
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 : for the system shown below K1=20N/m K1=10N/m K1=20N/m K1=50N/mFind W such that the natural frequency of the system will be 1.592 cycles per second a)0.125kg b)0.25kg c)0.5kg 4)4kg
Last Answer : b)0.25kg
Description : The ratio of actual damping coefficient to the critical damping coefficient is known as A Magnification Factor B Damping Factor C Logarithmic decrementD None of the mentioned
Last Answer : B Damping Factor
Description : In a 2-mass 3 spring vibrating system the two masses each are of 9.8 kg coupling spring is having a stiffness of 3430 N/m whereas the other two springs have each a stiffness of 8820 N/m. The two natural frequencies in rad /sec are A) 10 & 20 B) 20 & 30 C) 30 & 40D) 40 & 50
Last Answer : C) 30 & 40
Description : Beats phenomenon occurs when a vibrating system is subjected to two different frequencies which are A) Quite different B) Equal C) Slightly different D) Integral multiple of each other
Last Answer : C) Slightly different
Description : A system is said to be critically damped if the damping factor for a vibrating system is A Zero B Less than one C One D More than one
Last Answer : C One
Description : When parts of a vibrating system slide on a dry surface, the damping is A. Viscous. B. Coulomb C. Structural D. Eddy current
Last Answer : B. Coulomb