Vehicle Dynamics Mid - I, September - 2014

1.Rayleigh’s energy method is represented by
  • Tmax=Umax
  • Tmax=-Umax
  • -2146826259
  • none
Answer: A
2.When ω/ωn=1this is termed as
  • Viscous damping
  • Resonance
  • structural damping
  • none of the above
Answer: B
3.What is the degree of freedom for simple Pendulum?
  • 3
  • 0
  • 1
  • Infinite
Answer: C
4.In a spring mass system if the mass is halved and the spring stiffness is doubled the natural frequency is
  • Halved
  • Doubled
  • Quadrupled
  • Unchanged
Answer: B
5.The transient vibrations in forced vibrations with constant harmonic excitation takes place at
  • Damped natural frequency of the system
  • Natural frequency of the system
  • Frequency of the excitation
  • Cannot be predicted
Answer: A
6.Magnification factor of damping system
  • 1/[(1-r2)2 + (2 ξr)2]3
  • 1/(1-r2)2
  • 1/[(1-r2)2 + (2 ξr)2]½
  • [(1-r2)2 + (2 ξr)2]1/2
Answer: C
7.The damping ratio is a parameter, usually denoted by
  • ζ (Zeta)
  • Δ (delta)
  • μ (mu)
  • α(Alpha)
Answer: A
8.The factor which effect the critical speed of a shaft is
  • Eccentricity
  • diameter of the disc
  • span of the shaft
  • all of the above
Answer: D
9.If two springs are Connected in series of equal stiffness , then the equivalent stiffness become
  • Same
  • Doubles
  • Become Half
  • none
Answer: C
10.The equivalent stiffness of axial bar of length ‘ L ‘ cross –sectional area A, and young’s modulus E is
  • AL/E
  • AE/L
  • EL/A
  • none
Answer: B
11.Coulomb Damping is also known as____________ damping.
Answer: Frictional
12.The unbalanced force caused by an eccentric mass m, rotating at an angular speed ω and located at a distance r from the axis of rotation is ______________
Answer: mrω²
13.A gun barrel of mass 600 kg has a recoil spring of stiffness 600N/m. The critical damping coefficient is _____________
Answer: 1200 N-Sec/m
14.Frahm’s Reed Tachometer is used to measure _________________ of a vibrating system
Answer: Frequency
15.Where the spring–mass system is completely lossless, the mass would oscillate indefinitely, with each bounce of equal height to the last. This hypothetical case is called __________________
Answer: Undamped
16.Steady state solution for forced vibration with damping is give by__________________
Answer: x(t)=Xsin(2πft+ɸ)
17.The frequency of damped vibrations is always ___________________the natural frequency.
Answer: 17. Less than
18.According to the D’Alembert’s principle, the sum of inertial forces and external forces is equal to _______.
Answer: Zero
19.Acceleration of a vibrating body is measured by_______________________________
Answer: Accelerometer
20.The equivalent stiffness of cantilever beam is ______________________________
Answer: 3EI/L³