Description : A shaft carrying three rotors will have A. No node B. One node C. Two node D. Three nodes
Last Answer : C. Two node
Description : A shaft carrying two rotors at its ends will have A. No node B. One node C. Two node D. Three nodes
Last Answer : B. One node
Description : A shaft carrying two rotor at its ends will have A No node B Two nodes C One node D Three nodes
Last Answer : C One node
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 : 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 : When heavy rotating masses are connected by a shaft and equal and opposite torques are applied to these masses (rotors) A. The rotors vibrate torsionally in the same direction. B. The rotors vibrate torsionally ... on the axis of shaft which remains undisturbed by vibration. D. Both (B) and (C)
Last Answer : D. Both (B) and (C)
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 : _______ 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 : 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 : 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 most practical situation the speed of rotation of the shaft is usually A) Much below the critical speed B) Much above the critical speed C) Near about the critical speed D) Having no relationship with critical speed
Last Answer : B) Much above the critical speed
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 : 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 : 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 : 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 : If two discs are attached to one shaft at its both end, then it has_____ number of natural frequencies. A Infinite B One C Two D None of the mentioned
Last Answer : B One
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 : 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 : 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 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 : 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 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 : 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
Description : Rotor shaft of a large electric motor supported between short bearings at both ends shows a deflection of 1.8 mm in middle of motor. Assuming rotor to be perfectly balanced and supported at knife edges at both ends, likely critical speed (rpm) of shaft isA 350 B 4430 C 705 D 2810
Last Answer : C 705
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 : The factor which affects critical speed shaft is....... A. eccentricity B. span of shaft C. diameter of disc D. all of above
Last Answer : D. all of above
Description : The critical speed of a shaft depends upon its A. Mass B. Stiffness C. Mass and stiffnessD. Stiffness and eccentricity
Last Answer : C. Mass and stiffness
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 _________ A. Whirling speed B. Rotational speed C. Stabilizing speed D. Reciprocating speed
Last Answer : A. Whirling speed
Description : The vibrations perpendicular to the shaft axis are known as A Transverse B Longitudinal C Torsional D None of the mentioned
Last Answer : A Transverse
Description : If the static deflection is 1.665×10 -3 m, calculate the critical speed of the shaft in rps. Centre of disc at 0.25m away from centre of axis of shaft. A. 8.64 B. 9.64 C. 10.64 D. 12.2
Last Answer : D. 12.2
Description : A cantilever shaft having 50 mm diameter and length of 300 mm has a disc of mass 100 kg at its free enD. The Young’s modulus for the shaft material is 200 GN/m 2 . Calculate the natural longitudinal frequency in Hz. A. 575B. 625 C. 525 D. 550
Last Answer : A. 575
Description : The critical speed of a shaft is affected by A. Diameter of the disc B. Eccentricity C. Span of shaft D. All of above
Last Answer : D. All of above
Description : For the same dimensions of the shaft which of the following has the greater natural frequency? A. Transverse B. Longitudinal C. Depends on thickness D. Depends upon length
Last Answer : B. Longitudinal
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 : Critical speed of shaft having a rotating disc in the middle is A) x/e = 1 / ( r^2 - 1 ) B) x/e = 1 / ( r^2 + 1 ) C) x/e = 1 / ( r^2 - 1^2 ) D) x/e = ( 1 + r) / ( r^2 – 1 )
Last Answer : A) x/e = 1 / ( r^2 - 1 )
Description : The rotating shaft or rotor vibrates with excessive lateral vibration at angular speed at which occurs is called as A) rotating speed B) critical speed C) vibrating speed D) None of the above
Last Answer : B) critical speed
Description : During transverse vibrations, shaft is subjected to which type of stresses? A) Tensile stresses B) Torsional shear stress C) Bending stresses D) All of the above
Last Answer : C) Bending stresses
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 measuring critical speed of shaft experiment, it was found that the frequency ratio is 0.707 when the eccentricity is 0.05 m. what will be the displacement of the system. A. 0.05 m B. 0.005 m C. 0.5 m D. Infinite
Last Answer : A. 0.05 m
Description : The factors which affects the critical speed of the shaft is A. Eccentricity B. Diameter of the Disc C. Span of the shaft D. All the above
Last Answer : D. All the above
Description : When the speed of rotation of a shaft equals one of the natural frequencies of the shaft, it is called____________speed.
Last Answer : Ans- Critical
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 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 : During transverse vibrations, shaft is subjected to which type of stresses? a. Tensile stresses b. Torsional shear stress c. Bending stresses d. All of the above
Last Answer : c. Bending stresses
Description : The factor which affects the critical speed of a shaft is a) diameter of the disc b) span of the shaft c) eccentricity d) all of the mentioned
Last Answer : d) all of the mentioned