Machine Dynamics

Flywheel

Question 1
Marks : +2 | -2
Pass Ratio : 100%
Which of the following statement is wrong?
The difference between the maximum and minimum energies is called maximum fluctuation of energy.
The co-efficient of fluctuation of speed is the ratio of maximum fluctuation of speed to the mean speed.
The variations of energy above and below the mean resisting torque line is known as fluctuation of energy.
None of the mentioned
Explanation:
All the statements are correct.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
Maximum fluctuation of energy in a flywheel is equal to
Iω(ω1 – ω2)
Iω2CS
2ECS
all of the mentioned
Explanation:
None
Question 3
Marks : +2 | -2
Pass Ratio : 100%
The ratio of maximum fluctuation of speed to the mean speed is called
fluctuation of energy
maximum fluctuation of energy
coefficient of fluctuation of speed
none of the mentioned
Explanation:
The co-efficient of fluctuation of speed is the ratio of maximum fluctuation of speed to the mean speed.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
If the rotating mass of a rim type flywheel is distributed on another rim type flywheel whose mean radius is half the mean radius of the former, then energy stored in the latter at the same speed will be
four times the first one
same as the first one
one fourth of the first one
one and a half times the first one
Explanation:
None
Question 5
Marks : +2 | -2
Pass Ratio : 100%
The maximum fluctuation of energy is the
difference between the maximum and minimum energies
sum of the maximum and minimum energies
variations of energy above and below the mean resisting torque to the
ratio of the mean resisting torque to the workdone per cycle
Explanation:
The difference between the maximum and the minimum energies is known as maximum fluctuation of energy.
Question 6
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Pass Ratio : 100%
The flywheel of a machine having weight of 4500 N and radius of gyration of 2 m has cyclic fluctuation of speed from 125 r.p.m to 120 r.p.m. Assuming g = 10m/s2, the maximum fluctuation of energy is
12822 N-m
24200 N-m
14822 N-m
12100 N-m
Explanation:
Mass of flywheel = weight of flywheel/Acceleration due to gravity = 4500/10kg
Question 7
Marks : +2 | -2
Pass Ratio : 100%
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
2WCE/CS
WCE/2CS
WCE/CS
WCS/2CE
Explanation:
None
Question 8
Marks : +2 | -2
Pass Ratio : 100%
The ratio of maximum fluctuation of energy to the workdone per cycle is called
fluctuation of energy
maximum fluctuation of energy
coefficient of fluctuation of speed
none of the mentioned
Explanation:
The co-efficient of fluctuation of speed is the ratio of maximum fluctuation of speed to the mean speed.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
The co-efficient of fluctuation of energy is the ratio of maximum energy to the minimum energy.
True
False
Explanation:
The co-efficient of fluctuation of energy is the ratio of the maximum fluctuation of energy to the work done per cycle.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
In a four stroke I.C. engine, the turning moment during the compression stroke is
positive throughout
negative throughout
positive during major portion of the stroke
negative during major portion of the stroke
Explanation:
Since the pressure inside the engine cylinder is less than the atmospheric pressure during the suction stroke, therefore a negative loop is formed. During the compression stroke, the work is done on the gases, therefore a higher negative loop is obtained.