Mechanical Technology Mid - I, September - 2014

1.The Cam and Follower is an example of
  • sliding pair
  • rolling pair
  • lower pair
  • higher pair
Answer: D
2.The size of cam depends upon
  • base circle
  • pitch circle
  • prime circle
  • pitch curve
Answer: A
3.Pitch point of a cam is
  • a point on the pitch curve having minimum pressure angle
  • a point on the pitch curve having maximum pressure angle
  • any point on the pitch curve
  • any point on the pitch circle
Answer: B
4.In a cam drive with uniform velocity follower, the sharp corners of the displacement diagram are rounded off at the beginning at the end of each stroke. This is done
  • because of difficulty in manufacturing cam profile
  • because of loose contact of follower with cam surface
  • in order to have acceleration in beginning and retardation at the end of stroke within the finite limits
  • because the uniform velocity motion is a partial parabolic motion
Answer: C
5.The cam follower generally used in automobile engines is
  • knife edge follower
  • flat faced follower
  • spherical faced follower
  • roller follower
Answer: C
6.In a cone pulley, if the sum of radii of the pulleys on the driving and driven shafts is constant, then
  • open belt drive is recommended
  • crossed belt drive is recommended
  • both open belt drive and crossed belt drive is recommended
  • the drive is recommended depending upon the torque transmitted
Answer: B
7.Due to slip of belt, the velocity ratio of the belt drive
  • Increases
  • Decreases
  • does not change
  • zero
Answer: B
8.Two pulleys of radii R and r at distance x apart are connected by means of an open belt drive.The length of the belt is
Answer: B
9.V-belts are usually used for
  • long drives
  • short drives
  • long and short drives
  • none of these
Answer: B
10.In a multiple V-belt drive, if one of the belt is broken, then we should replace
  • the broken belt only
  • all the belts
  • the broken belt and the belts on either side of it
  • none of the above
Answer: B
11.When two pulleys are connected by means of an open belt drive, then both the pulleys will rotate in ....................................... directions.
Answer: same
12.Two pulleys of radii R and r at distance x apart are connected by means of a cross belt drive.The length of the belt is ................................
Answer: ​
13.When two pulleys of different diameters are connected by means of an open belt, the angle of contact at the ..................................... pulley must be taken into consideration.
Answer: smaller
14.The power transmitted by a belt is maximum when the maximum tension in the belt is ................................. of centrifugal tension.
Answer: three times
15.The velocity of the belt for maximum power is ..............................
Answer:
16.The pressure angle of a cam is the angle between the direction of the follower motion and a normal to the ......................................
Answer: pitch curve
17.The Cam with ................................. follower generally used in air-craft engines.
Answer: roller
18.For high speed engines, the cam follower should move with ..................................
Answer: cycloidal motion
19.The acceleration of the reciprocating roller follower when it has contact with the straight flanks of tha t angent cam is given by ....................
Answer:
20.The velocity of a flat faced follower when it has contact with the flank of a circular arc cam, is given by ............................................
Answer: