Vibrations and Aeroelasticity MCQs

1. Which of the following describes a free vibration?
(A) Vibration that occurs due to an external force
(B) Vibration occurring in the absence of any external force
(C) Vibration at the resonance frequency
(D) Vibration with varying amplitude

2. What is the natural frequency of a system?
(A) The frequency at which the system vibrates under external excitation
(B) The frequency at which the system tends to oscillate in the absence of damping and external forces
(C) The frequency at which resonance occurs
(D) The frequency of any arbitrary vibration

3. In a damped system, which of the following occurs?
(A) The amplitude of vibration increases over time
(B) The amplitude of vibration decreases over time
(C) The system remains at its natural frequency
(D) The system reaches a steady-state amplitude

4. Which type of damping is characterized by a force proportional to velocity?
(A) Coulomb damping
(B) Viscous damping
(C) Structural damping
(D) Hysteresis damping

5. What is the mode shape in a vibrating system?
(A) The amplitude of vibration
(B) The displacement pattern of the system during vibration
(C) The frequency of the vibration
(D) The phase difference between displacement and force

6. Which of the following best describes resonance?
(A) The condition where damping is zero
(B) The condition where the frequency of excitation matches the natural frequency of the system
(C) The condition where the system is underdamped
(D) The condition where the system is overdamped

7. Which type of vibration is characterized by energy being continuously transferred from one form to another?
(A) Forced vibration
(B) Free vibration
(C) Resonant vibration
(D) Natural vibration

8. In simple harmonic motion, the acceleration is proportional to which of the following?
(A) Velocity
(B) Displacement
(C) Time
(D) Frequency

9. Which type of damping is present when the system returns to its equilibrium position without oscillation?
(A) Overdamping
(B) Underdamping
(C) Critical damping
(D) Hysteresis damping

10. What is the primary cause of vibration in rotating machinery?
(A) Imbalance
(B) Thermal expansion
(C) Corrosion
(D) Electromagnetic interference