Description : What are discrete parameter systems? *1 point (A) Systems which have infinite number of degree of freedom (B) Systems which have finite number of degree of freedom (C) Systems which have no degree of freedom (D) None of the above
Last Answer : (B) Systems which have finite number of degree of freedom
Description : What are discrete parameter systems? A. Systems which have infinite number of degree of freedom B. Systems which have finite number of degree of freedom C. Systems which have no degree of freedom D. None of the above
Last Answer : B. Systems which have finite number of degree of freedom
Description : What are discrete parameter systems?a. Systems which have infinite number of degree of freedom b. Systems which have finite number of degree of freedom c. Systems which have no degree of freedom d. None of the above
Last Answer : b. Systems which have finite number of degree of freedom
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 : 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 : Which of the following systems produce a vibration in the foundation? (A) Coupled machine (B) Uncoupled machine (C) Balanced machine (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 : Which performance parameter is the minimum amount of optical power required to achieve a specific bit-error rate (BER) in digital systems or a given signal-to-noise ratio (SNR) in analog systems?
Last Answer : Receiver sensitivity.
Description : Often an unbalance of forces is produced in rotary or reciprocating machinery due to the ______ * 1 point (A) Centripetal forces (B) Centrifugal forces (C) Friction forces (D) Inertia forces
Last Answer : (D) Inertia forces
Description : If the spring mass system with m and spring stiffness k is taken to very high altitude, the natural frequency of longitudinal vibrations * 1 point (A) increases (B) decreases (C) remain unchanged (D) may increase or decrease depending upon the value of the mass
Last Answer : (C) remain unchanged
Description : The speed at which the shaft runs so that the additional deflection from the axis of rotation of the shaft becomes infinite, is known as _________ * 1 point (A) Whirling speed (B) Rotational speed (C) Stabilizing speed (D) Reciprocating speed
Last Answer : (A) Whirling speed
Description : Frequency is equal to ______. * 1 point (A) time period (B) 1/time period (C) *time period (D) /time period
Last Answer : (B) 1/time period
Description : What are deterministic vibrations? * (A)Vibrations caused due to known exciting force (B)Vibrations caused due to unknown exciting force (c) Vibrations which are aperiodic in nature (D) None of the above
Last Answer : (A)Vibrations caused due to known exciting force
Description : Equilibrium Method is in accordance with which of the following principle? * 1 point (A) Taylor's principle (B) D'Alembert's principle (C) Energy conservation principle (D) None of the above
Last Answer : (B) D'Alembert's principle
Description : According to which method, maximum kinetic energy at mean position is equal to maximum potential energy at extreme position? * 1 point (A) Energy method (B) Rayleigh's method (C) Equilibrium method (D) All of the above
Last Answer : (B) Rayleigh's method
Description : A mass of 1 kg is attached to two identical springs each with stiffness k = 20 kN/m as shown in the figure. Under frictionless condition, the natural frequency of the system in Hz is close to * 1 point (A) 32 (B) 23 (C) 16 (D) 11
Last Answer : (A) 32
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 : The equivalent stiffness of spring connected in parallel having stiffnesses k1 and k2 can be written as * 1 point (A)(1/k1) + (1/k2) (B) (1/k1) - (1/k2) (C) k1 + k2 (D) None of the above
Last Answer : (C) k1 + k2
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 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 : When the body vibrates under the influence of external force, then the body is said to be under ___________ . * 1 point (A) free vibrations (B) natural vibrations (C) forced vibrations (D) damped vibrations
Last Answer : (C) forced vibrations
Description : When a rigid body is suspended vertically and it oscillates with a small amplitude under the action of the force of gravity, the body is known as * 1 point (A) simple pendulum (B) torsional pendulum (C) compound pendulum (D) second’s pendulum
Last Answer : (C) compound pendulum
Description : The natural frequency of a spring-mass system on earth is ωn. The natural frequency of this system on the moon (g of moon = g of earth /6) is * 1 point (A) ωn (B) 0.408ωn (C) 0.204ωn (D) 0.167ωn
Last Answer : (A) ωn
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 centrifugal pendulum absorber , the natural frequency in cycle per second can be given by A Fn =N √(R/L) B Fn =1/N √(R/L) C Fn =N/2 √(R/L) D Fn =N2 √(R/L)
Last Answer : A Fn =N √(R/L)
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 : Untuned viscous damper ( houdaille Damper) is used with variable speed machine being control by ratio can be given by A) (damper inertia) / (main system inertia) B) (main system inertia) / (damper inertia) ... X damper inertia) / (main system inertia) D) (2 X main system inertia) / (damper inertia)
Last Answer : A) (damper inertia) / (main system inertia)
Description : In Fullarton Tachometer, a thin strip with a ______ is attached at one of its ends. (A) mass (B) spring (C) damper (D) shaft
Last Answer : (A) mass
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 also known as low-frequency Transducer? (A) Stroboscope (B) Accelerometer (C) Vibrometer (D) None of the above
Last Answer : (C) Vibrometer
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 : 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 speed at which the shaft runs so that the additional deflection of the shaft from the axis of rotation becomes ___________, is known as critical or whirling speed. (A) zero (B) minimum (C) maximum (D) infinite
Last Answer : (D) infinite
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 : 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 : 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 : For a two-rotor system, the length of one shaft (A) is twice the other (B), then what is the relation between the mass moment of inertia of the shafts. A 2I(A) = I(B) B I(A) = 2I(B) C I(A) = I(B) D 2I(A) = 3I(B)
Last Answer : A 2I(A) = I(B)
Description : Magnification factor is the ratio of the maximum displacement due to forced vibrations to the deflection due to _______ A Static force B Dynamic force C Torsion D Compression
Last Answer : A Static force
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 : For an under damped harmonic oscillator, resonance A Occurs when excitation frequency is greater than undamped natural frequency B Occurs when excitation frequency is less than undamped natural frequency C Occurs when excitation frequency is equal to undamped natural frequency D Never occurs
Last Answer : C Occurs when excitation frequency is equal to undamped natural frequency
Description : The first critical speed of an automobile running on a sinusoidal road is calculated by (modeling it as a single degree of freedom system) A Resonance B Approximation C Superposition D Rayleigh quotient
Last Answer : A Resonance
Description : Critical speed is expressed as A rotation of shaft in degrees B rotation of shaft in radians C rotation of shaft in minutes D natural frequency of the shaft
Last Answer : D natural frequency of the shaft
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 : 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 : 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 : 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 : 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 : The static deflection of a spring under gravity, when a mass of 1 kg is suspended from it, is 1 mm. Assume the acceleration due to gravity g = 10 m/s^2. The natural frequency of this spring-mass system (in rad/s) is A 100 B 150 C 200 D 250
Last Answer : A 100
Description : A cantilever shaft having 50 mm diameter and a length of 300mm 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 static deflection of shaft in mm. A 0.144 B 0.244 C 0.344 D 0.444
Last Answer : A 0.144