Description : Which of the following systems produce a vibration in the foundation? (A) Coupled machine(B) Uncoupled machine (C) Balanced machine (D) Unbalanced machine
Last Answer : (D) Unbalanced machine
Description : Which of the following systems produce a vibration in the foundation? a) Unbalanced machine b) Balanced machine c) Coupled machine d) Uncoupled machine
Last Answer : a) Unbalanced machine
Description : The equations of motion of a two degree of freedom system, are, in general: A. coupled B. linear C. uncoupled D. none of the above
Last Answer : A. coupled
Description : What Are The Causes Of Vibration? a. Unbalanced centrifugal forces in the system. b. Elastic nature of the system. c. Winds may cause vibrations of certain systems such as electricity lines, telephones lines etc. d. All of the above
Last Answer : d. All of the above
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 : During vibrations any machine has unbalanced force of 392N and if it transmitted force of magnitude 58.3N then transmissibility value is A 0.481 B 0.822 C 0.148 D 0.296
Last Answer : C 0.148
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 : 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 : Dynamic vibration absorber is suitable for A) Constant speed machine B) Varying speed machine C) zero speed machine D) None of the above
Last Answer : A) Constant speed machine
Description : Calculate natural frequency of damped vibration, if damping factor is 0.52 and A 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 : Calculate natural frequency of damped vibration, if damping factor is 0.52 and natural frequ the system is 30 rad/sec which consists of machine supported on springs and dashpots. a. 25.62 rad/secb. 20.78 rad/sec c. 14.4 rad/sec d. 15.33 rad/sec
Last Answer : a. 25.62 rad/sec
Description : When a periodic disturbing force is applied to a machine, the force is transmitted to the ___________ by the means of spring. (A) dampers (B) foundation (C) mass (D) none of the above
Last Answer : (B) foundation
Description : When a periodic disturbing force is applied to a machine, the force is transmitted to the foundation by the means of spring. a) True b) False
Last Answer : a) True
Description : The loads on distributors systems are generally (a) balanced (b) unbalanced (c) either of the above (d) none of the above
Last Answer : (b) unbalanced
Description : The unbalanced force caused by an eccentric mass m rotating at an angular speed v and located at a distance r from the axis of rotation is 2 a. mr ω 2 b. mgω 2 c. mr ω 2
Last Answer : c. mr ω 2
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 : What is meant by coupled differential equation? A. The differential equation in which only rectilinear motions exit B. The differential equation in which only angular motions exit C. The differential equation in which both rectilinear and angular motions exit D. None of the above
Last Answer : C. The differential equation in which both rectilinear and angular motions exit
Description : What is meant by coupled differential equation? A) The differential equation in which only rectilinear motions exit B) The differential equation in which only angular motions exit C) The differential equation in which both rectilinear and angular motions exit D) None of the above
Last Answer : C) The differential equation in which both rectilinear and angular motions exit
Description : What is meant by coupled differential equation? a. The differential equation in which only rectilinear motions exit b. The differential equation in which only angular motions exit c. The differential equation in which both rectilinear and angular motions exit d. None of the above
Last Answer : c. The differential equation in which both rectilinear and angular motions exit
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 : The vibration in a vehicle is normally expressed in the terms of the ______________. (A) displacement (B) velocity (C) acceleration (D) none of the above
Last Answer : (C) acceleration
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 : The accelerometers are commonly used in vibration measurement due to their ___________. (A) small size and low sensitivity (B) the large size and high sensitivity (C) the large size and low sensitivity (D) small size and high sensitivity
Last Answer : (D) small size and high sensitivity
Description : From the following, which one is a type of vibration measuring instrument? A Mechanical B Electrical C Magnetic D All of the above
Last Answer : D All of the above
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 : 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 ... is equal to the frequency of vibration D Measurement of vibratory motion is without any reference point
Last Answer : C Its natural frequency is equal to the frequency of vibration
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 : 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 : 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 : 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 : The number of cycles described in one second is known as _______. A period of vibration B cycle C frequency D all of the above
Last Answer : C frequency
Description : The motion completed during one time period is known as _______. A period of vibration B cycle C frequency D all of the above
Last Answer : B cycle
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 : The motion of a system executing harmonic motion with one natural frequency is known as _______ A. principal mode of vibration B. natural mode of vibration C. both a. and b. D. none of the above
Last Answer : C. both a. and b.
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 : What is meant by node point? A. The point at which amplitude of vibration is maximum B. The point at which amplitude of vibration is minimum C. The point at which amplitude of vibration is zero D. None of the above
Last Answer : C. The point at which amplitude of vibration is zero
Description : In a dynamic vibration absorber system, under tuned conditions which of the following relation holds good? A K 1 K 2 =M 1 M 2 B K 1 M 2 =M 1 K 2 C K 1 M 1 = K 2 M 2 D none of the mentioned
Last Answer : B K 1 M 2 =M 1 K 2
Description : Dynamic vibration absorber is suitable for A varying speed machines B constant speed machines C Zero speed range machines D None of the mentioned
Last Answer : B constant speed machines
Description : During resonance A the Vibrations remains unaffected B no vibration occurs C low amplitude of vibration occurs D high amplitude of vibration occurs
Last Answer : D high amplitude of vibration occurs
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 : In coulomb damping the frequency of damped vibrations is A Equal to that of undamped vibrations B Less than that of undamped vibrationsC More than that of undamped vibrations D Independent of the frequency of undamped vibration
Last Answer : A Equal to that of undamped vibrations
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 : 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 : 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°
Description : In vibration isolation system, the transmissibility will be equal to unity, for all values of damping factor, if ω/ωn is A. Equal to 1 B. Equal to √2 C. Less than √2 D. Greater than √2
Last Answer : B. Equal to √2
Description : An increase in the mass moment of inertia results in ________ in vibration frequency. A. increase B. decrease C. unchanged D. none of the above
Last Answer : B. decrease
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 : The motion completed during one time period is known as _______. A. period of vibration B. cycle C. frequency D. all of the above
Last Answer : B. cycle
Description : . The motion completed during one time period is known as _______. A. period of vibration B. cycle C. frequency D. all of the above