# Dynamics of Machinery 2

Mechanical Engineering MCQ Question Papers: DRDO, ISRO, Interview

Subject: Dynamics of Machinery 2

Part 2: List for questions and answers of Dynamics of Machinery

Q1. 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

Q2. 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

Q3. 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

Q4. What is the effect of damping on phase angle at resonance frequency?
a) Phase angle increases as damping increases
b) Damping has no effect on phase angle
c) Phase angle increases as damping decreases
d) None of the above

Q5. When frequency ratio (ω/ωn) is greater than unity, phase angle decreases as ______
a) Damping factor increases
b) Damping factor decreases
c) Both a. & b.
d) None of the above

Q6. At which frequency ratio, phase angle increases as damping factor increases?
a) When frequency ratio is less than unity
b) When frequency ratio is more than unity
c) When frequency ratio is zero
d) All of the above

Q7. In damped free vibrations, which parameters indicate vibrations?
a) Natural frequency
b) Rate of decay of amplitude
c) Both a. & b.
d) None of the above

Q8. What is meant by critical damping coefficient?
a) Frequency of damped free vibrations is less than zero
b) The motion is periodic in nature
c) Both a. & b.
d) None of the above

Q9. Which of the following relations is true for viscous damping?
a) Force α relative displacement
b) Force α relative velocity
c) Force α (1 / relative velocity)
d) None of the above

Q10. Eddy current damping is an example of _____
a) Coulomb damping
b) Hysteresis damping
c) Viscous damping
d) Dry friction damping

Q11. Two springs have spring stiffness of 1500 n/m and 2000 n/m respectively. If they are connected in series, what is the spring stiffness if they are replaced by an equivalent system.3500 n/m?
a) 3500 n/m
b) 1166 n/m
c) 857.63 n/m
d) None of the above

Q12. Which type of vibrations are also known as transient vibrations?
a) Undammed vibrations
b) Damped vibrations
c) Torsional vibrations
d) Transverse vibrations

Q13. 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

Q14. Which of the following relations is true when springs are connected parallelly? Where k = spring stiffness
a) Ke = k1 + k2
b) (1 / ke) = (1/k1) + (1/ k2)
c) Ke = (1/k1) + (1/ k2)
d) None of the above

Q15. The unbalanced primary couple caused due to reciprocating mass of each cylinder is given as
a) Mrlω2 cos θ
b) Mrlω (cos θ / n)
c) Mrlω2 cos 2θ
d) Mrω2 cos 2θ

Q16. Which of the following conditions should be satisfied for complete balancing of multicylinder inline engines?
a) Primary couples should be balanced
b) Secondary couples should be balanced
c) Both a. And b.
d) None of the above

Q17. At which angle primary unbalanced force in reciprocating engine mechanism is maximum?
a) 0 deg.
b) 90 deg.
c) 360 deg.
d) All of the above

Q18. Secondary force in reciprocating engine mechanism is caused due to _______
a) S.H.M. Of reciprocating parts
b) Oscillation of reciprocating parts
c) Obliquity of arrangement of reciprocating parts
d) All of the above

Q19. What will be the sound power level, if a machine generates 20 w powers?
a) 124 db
b) 133 db
c) 150 db
d) 200 db

Q20. Which of the following is the reference pressure often referred to as threshold of hearing at 1000 Hz?
a) 5 x 10-5 n/m^2
b) 3 x 10-5 n/m^2
c) 2 x 10-5 n/m^2
d) None of the above

Part 2: List for questions and answers of Dynamics of Machinery