When the speed of rotation of a shaft equals one of the natural frequencies of the shaft, it is called____________speed.

When the speed of rotation of a shaft equals one of the natural frequencies of the shaft, it is
called____________speed.
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Ans- Critical
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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

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Last Answer : D natural frequency of the shaft

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

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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

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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

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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

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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) 575 b) 625 c) 525 d) 550

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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

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The factor which affects critical speed shaft is....... A. eccentricity B. span of shaft C. diameter of disc D. all of above

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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

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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

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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

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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

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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

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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

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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

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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

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During free vibration, different degrees of freedom oscillate at different frequencies.

Description : During free vibration, different degrees of freedom oscillate at different frequencies.

Last Answer : False

In a slider crank mechanism, the crank is rotating at 200 rpm. If length of connecting rod is 8 mts and crank shaft is 2 mts, velocity of crosshead at 30? rotation of crank shaft equals. a.30.2 m/s b.33.2 m/s c.35.8 mts/s d.107 dynes e.25.5 m/s

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Last Answer : e. 25.5 m/s

In Fullarton Tachometer, a thin strip with a ______ is attached at one of its ends. (A) mass (B) spring (C) damper (D) shaft

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Last Answer : (A) mass

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)

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)

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

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

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

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

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 rotate in same direction C. Zero node behavior is observed in rotors rotating in opposite direction D. All of the above

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

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

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

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

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

A shaft carrying three rotors will have A No node B Two nodes C One node D Three nodes

Description : A shaft carrying three rotors will have A No node B Two nodes C One node D Three nodes

Last Answer : B Two nodes