Question 1

From the given data, find the balancing mass's inclination in degrees if r=0.2m required in the same plane.Masses = 200kg, 300kg, 240 kg, 260Kg,

Accepted Answer

A)  201.48
B)  200.32
C)  210.34
D)  202.88 A

Question 2

In order to achieve stability, the sum of secondary forces and secondary couples must be ------- and their respective polygons must be …......

Accepted Answer

A)  Zero, Closed
B)  one, Open
C)  Zero, open
D)  one, closed A

Question 3

Which of the following statements are associated with complete dynamic balancing of rotating systems?
1) Resultant couple due to all inertia forces is zero.
2) Support reactions due to forces are zero but not due to couples .
3) The system is automatically statically balanced.
4) Centre of masses of the system lies on the axis of rotation.

Accepted Answer

A)  1, 2, 3 and 4
B)  1, 2, and 3 only
C)  2, 3 and 4 only
D)  1, 3 and 4 only D

Question 4

Let the disturbing mass be 100 kg and the radius of rotation be 10 cm and the rotation speed be 50 rad/s, then calculate the centrifugal force in kN.

Accepted Answer

A)  50
B)  25
C)  50000
D)  25000

Question 5

A V-twin engine has the cylinder axes at 90 degrees and the connecting rods operate a common crank. The reciprocating mass per cylinder is 34.5 kg and the crank radius is 7.5 cm. The length of the connecting rod is 0.3 m. If the engine is rotating at the speed is 500 r.p.m. What is the value of maximum resultant secondary force in kN?

Accepted Answer

A)  2.238
B)  2.508
C)  2.754
D)  2.908

Question 6

From the following data of a 60 degree V-twin engine, determine the maximum value for primary forces in newtons:Reciprocating mass per cylinder = 1.5 Kg Stroke length = 10 cm Length of connecting rod = 25 cm Engine speed = 2500 rpm

Accepted Answer

A)  7711
B)  4546
C)  2570
D)  8764

Question 7

If all the masses are in one plane, then what is the maximum no. of masses which can be placed in the same plane?

Accepted Answer

A)  3
B)  4
C)  6
D)  No limitation

Question 8

A V-twin engine has the cylinder axes at 90 degrees and the connecting rods operate a common crank. The reciprocating mass per cylinder is 11.5 kg and the crank radius is 7.5 cm. The length of the connecting rod is 0.3 m. If the engine is rotating at the speed is 500 r.p.m. What is the value of maximum resultant secondary force in Newtons?

Accepted Answer

A)  736
B)  836
C)  936
D)  636

Question 9

Which of the following statement is correct?

Accepted Answer

A)  In any engine, 100% of the reciprocating masses can be balanced dynamically
B)  In the case of balancing of multicylinder engine, the value of secondary force is higher than the value of the primary force
C)  In the case of balancing of multimass rotating systems, dynamic balancing can be directly started without static balancing done to the system
D)  none of the mentioned

Question 10

For the secondary balancing of the engine, which of the condition is necessary?

Accepted Answer

A)  Secondary force polygon must be close
B)  Secondary force polygon must be open
C)  Primary force polygon must be close
D)  Primary force polygon must be open

Question 11

Which of the following statements is correct about the balancing of a mechanical system?

Accepted Answer

A)  If it is under static balance, then there will be dynamic balance also
B)  If it is under dynamic balance, then there will be static balance also
C)  Both static as well as dynamic balance have to be achieved separately
D)  None of the mentioned

Question 12

The numerical values of the secondary forces and secondary couples couples may be obtained by considering the ___________

Accepted Answer

A)  Revolving mass
B)  Reciprocating mass
C)  Translating mass
D)  Rotating mass

Question 13

Which of the following is the correct expression for secondary force?

Accepted Answer

A)  m?^2 r.cos2?/n
B)  m ?^2 r.sin2?/n
C)  m?^2 r.tan2?/n
D)  m?^2 r.cos?/n

Question 14

A V-twin engine has the cylinder axes at 90 degrees and the connecting rods operate a common crank. The reciprocating mass per cylinder is 23 kg and the crank radius is 7.5 cm. The length of the connecting rod is 0.3 m. If the engine is rotating at the speed is 500 r.p.m. What is the value of maximum resultant secondary force in Newtons?

Accepted Answer

A)  7172
B)  1672
C)  1122
D)  1272

Question 15

From the given data, find the balancing mass in Kg if r=0.2m required in the same plane.Masses = 200kg, 300kg, 240 kg, 260Kg, corresponding radii = 0.2m, 0.15m, 0.25m and 0.3m.Angles between consecutive masses = 45, 75 and 135 degrees.

Accepted Answer

A)  116
B)  58
C)  232
D)  140

Question 16

In balancing of single-cylinder engine, the rotating unbalance is ____________

Accepted Answer

A)  completely made zero and so also the reciprocating unbalance
B)  completely made zero and the reciprocating unbalance is partially reduced
C)  partially reduced and the reciprocating unbalance is completely made zero
D)  partially reduced and so also the reciprocating unbalance

Question 17

Let the disturbing mass be 200 kg and the radius of rotation be 20 cm and the rotation speed be 50 rad/s, then calculate the centripetal force in kN.

Accepted Answer

A)  -50
B)  -25
C)  -100
D)  -2500

Question 18

From the following data of a 60 degree V-twin engine, determine the minimum value for primary forces in newtons:Reciprocating mass per cylinder = 1.5 Kg Stroke length = 10 cm Length of connecting rod = 25 cm Engine speed = 2500 rpm

Accepted Answer