Theory Of Machine - Study Mode

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[#456] Whirling speed of the shaft is the speed at which

(A) Shaft tends to vibrate in longitudinal direction

(B) Torsional vibrations occur

(C) Shaft tends to vibrate vigorously in transverse direction

(D) Combination of transverse and longitudinal vibration occurs

Correct Answer

(C) Shaft tends to vibrate vigorously in transverse direction

[#457] If the damping factor for a vibrating system is unity, then the system will be

(A) Over damped

(B) Under damped

(C) Critically damped

(D) Without vibrations

Correct Answer

(C) Critically damped

[#458] The equation of motion for a vibrating system with viscous damping is $$frac{{{d^2}x}}{{d{t^2}}} + frac{c}{m} imes frac{{dx}}{{dt}} + frac{s}{m} imes x = 0.$$ xa0 xa0 xa0If the roots of this equation are real, then the system will be

(A) Over-damped

(B) Under damped

(C) Critically damped

(D) Without vibrations

Correct Answer

(A) Over-damped

[#459] An eccentric sheave pivoted at one point rotates and transmits oscillatory motion to a link whose one end is pivoted and other end is connected to it. This mechanism has

(A) 2 links

(B) 3 links

(C) 4 links

(D) 5 links

Correct Answer

(C) 4 links

[#460] If $$frac{omega }{{omega { ext{n}}}} = 2,$$ xa0where co is the frequency of excitation and $${omega { ext{n}}}$$ is the natural frequency of vibrations, then the transmissibility of vibration will the

(A) 0.5

(B) 1

(C) 1.5

(D) 2

Correct Answer

(B) 1