WorksheetsBalancing of rotating masses
Total questions: 10
Worksheet time: 12mins
Often an unbalance of forces is produced in rotary or reciprocating machinery due to the ______
a) Centripetal forces
b) Centrifugal forces
c) Friction forces
d) Inertia forces
Which of the following is true for centrifugal force causing unbalance?
a) Direction changes with rotation
b) Magnitude changes with rotation
c) Direction and magnitude both change with rotation
d) Direction and magnitude both remain unchanged with rotation
What is not the effect of unbalanced forces?
a) Load on bearings
b) Dangerous vibrations
c) Stresses in various members
d) Violation of conservation of mass principle
What is the effect of a rotating mass of a shaft on a system?
a) Bend the shaft
b) Twist the shaft
c) Extend the shaft
d) Compress the shaft
In a system two masses are used to balance the unbalanced forces. Find the mass of the balancing mass which has to be situated at a distance of 20cm, if the disturbing mass is of 100 Kg having radius of rotation of 0.1m. One of the balancing mass is 30 Kg with RoR of 10cm.
a) 70
b) 35
c) 20
d) 10
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, corresponding radii = 0.2m, 0.15m, 0.25m and 0.3m.
Angles between consecutive masses = 45, 75 and 135 degrees.
a) 200.32
b) 201.48
c) 210.34
d) 202.88
If all the masses are in one plane, then what is the maximum no. of masses which can be placed in the same plane?
3
4
6
No Limitation
In a four stroke I.C. engine, the turning moment during the compression stroke is
a) positive throughout
b) negative throughout
c) positive during major portion of the stroke
d) negative during major portion of the stroke
Maximum fluctuation of energy in a flywheel is equal to
a) Iω(ω1 – ω2)
b) Iω2CS
c) 2ECS
d) all of the mentioned
The relation between stroke punch s and radius of crank r is ______
a) s=r
b) s=2r
c) s=4r
d) s=r/2
