DOM Model Exam-2 Part-B

For a 4 cylinder engine, if the minimum speed of the engine is half the maximum speed, then coefficient of fluctuation is _________

• a) 0.5
• b) 1.5
• c) 2
• d) 0.66

The tensile stress in the flywheel rim due to the centrifugal force acting on the rim is given by

• a) ρ v2/4
• b) ρ v2/2
• c) 3ρ v2/4
• d) ρ v2

A flywheel is fitted to the crankshaft of an engine having W as the amount of indicated work per revolution and permissible limits of coefficient of fluctuation of energy and speed as CE and CS respectively. The kinetic energy of the flywheel is given by

• a) 2WCE/CS
• b) WCE/2CS
• c) WCE/CS
• d) WCS/2CE

Let the disturbing mass be 100 kg and the radius of rotation be 20 cm and the rotation speed be 50 rad/s, then calculate the centrifugal force in kN.

• a) 50
• b) 25
• c) 50000
• d) 25000

Let the centrifugal force in kN be 25 and the radius of rotation be 20 cm and the rotation speed be 50 rad/s, then calculate the mass defect in Kg.

• a) 50
• b) 25
• c) 50000
• d) 25000

From the given data, calculate the unbalanced centrifugal force in N s2 Distance from shaft = 0.2 m Mass = 100 kg Rotating speed = 1000 rpm.

• a) 20
• b) 2×107
• c) 200
• d) 20000

 If the polar moment of inertia is increased to four times, then what will be the effect on free torsional vibrations of a single motor system?

• a) Increases 4 times
• b) Increases 2 times
• c) Decreases 4 times
• d) Decreases 2 times

Calculate the free torsional vibrations of a single motor system from the following data: C = 8 GN/m2, L=9m, I = 600 Kg-m2, J = 8×104 m4

• a) 162,132
• b) 172,132
• c) 182,132
• d) 192,132

Calculate the Polar moment of inertia in m4 of a single motor system from the following data: C = 8 GN/m2, L=9m, I = 600 Kg-m2, f=10 Hz

• a) 0.00027
• b) 0.00032
• c) 0.00045
• d) 0.00078

If the mass of the constraint is negligible then what is the kinetic energy of the system?

• a) 0
• b) Half the value
• c) Double the value
• d) Infinite