Dynamics of Machinery Mid - II, November - 2014

1.The ratio of maximum fluctuation of speed to the mean speed is called
  • fluctuation of speed
  • maximum fluctuation of speed
  • coefficient of fluctuation of speed
  • none of these
Answer: C
2.The maximum fluctuation of energy is the
  • Sum of maximum and minimum energies
  • Difference between maximum and minimum energies
  • ratio of the maximum and minimum energies
  • none of these
Answer: B
3.The effort of a governor is the force exerted by the governor on the
  • balls
  • sleeve
  • upper links
  • lower links
Answer: B
4.The height of a Watt governor is
  • g/3
  • 2/ g
  • g 2
  • g / 2
Answer: D
5.The condition of isochronism can be realized in a _________ governor.
  • Watt
  • Porter
  • Proell
  • Harnell
Answer: D
6.For complete dynamic balance, at least mass/masses are necessary
  • 2
  • 3
  • 4
  • 1
Answer: A
7.In reciprocating, the primary unbalanced force
  • cannot be balanced
  • can be fully balanced
  • can be partially balanced
  • none of these
Answer: C
8.The two rotors connected by a shaft when subjected to torsional vibrations will have degree of freedom
  • one
  • two
  • three
  • none of the these
Answer: A
9.In a spring – mass system, if the mass is halved and the spring stiffness is doubled, the natural frequency is
  • halved
  • doubled
  • unchanged
  • quadrupled
Answer: B
10.At a certain speed, revolving shafts tend to vibrate violently in transverse direction. The speed is known as
  • whirling speed
  • critical speed
  • whipping speed
  • all the above
Answer: D
11.Crank – effort diagram is the plot of _________________ Vs ___________________
Answer: Turning moment(T) , crank angle (θ)
12.____________ is used to control the variations in speed during each cycle of an engine
Answer: Fly Wheel
13.Co- efficient of fluctuation of speed is given by __________
Answer: K = e/2E = e/I 2
14.For spring controlled governors the controlling force curve would be _________
Answer: Straight line
15.Governor which is Hunting is ________ stable
Answer: Less
16.Partial balancing of reciprocating parts in locomotives produces _______________
Answer: Hammer blow
17.The swaying couple is maximum or minimum when the line of inclination of the crank with the line of stroke is equal to _______
Answer: 2250 to 450
18.Most of the engines generally do not require balancing of _____________
Answer: secondary couples
19.In a vibrating body under the conditions of resonance, the phase angle will be _______
Answer: 00
20.There are n rotors mounted on the shaft and when subjected to torsional vibration there will be ______ nodes.
Answer: n-1