Engineering Questions with Answers - Multiple Choice Questions
Machine Foundations – Mass Spring System
1 - Question
Most of the motions encountered in soil dynamics are __________
a) Plane linear motion
b) Motion by impact
c) Horizontal motion
d) All of the mentioned
View Answer
Answer: a
Explanation: Most of the motions encountered in soil dynamics work are those of vibration, plane linear motion, a motion brought about by impact, shock, elastic waves, and seismic action of geophysical forces.
2 - Question
The theory of harmonic vibrations is applicable to _________ for designing of foundation.
a) Turbines
b) Motors
c) Generators
d) All of the mentioned
View Answer
Answer: d
Explanation: The design of foundations of turbines, motors, generators, compressor, forge hammers and other machine having a rhythmic application of unbalanced forces requires special knowledge of the theory of harmonic vibrations.
3 - Question
The constituent part of soil mechanics which deals with soil under dynamic condition is _______
a) Mass spring system
b) Soil dynamics
c) Soil system
d) Mass system
View Answer
Answer: b
Explanation: Soil dynamics is defined as that constituent part of soil mechanics which deals with soil under dynamic conditions.
4 - Question
The factor responsible for additional dynamic load in rotating machines are ________
a) Static load and Inertial force
b) Geophysical force
c) None of the mentioned
d) All of the mentioned
View Answer
Answer: a
Explanation: Inertial forces of rotating elements of machines contribute besides their static loads, additional dynamic loads.
5 - Question
In soil dynamics problems, the analysis may be conveniently carried out by ___________
a) Spring mass system
b) Inertial force
c) Free vibration
d) Amplitude test
View Answer
Answer: a
Explanation: In soil dynamic problems, the analysis may be conveniently carried out by a single equivalent mass supported by a perfectly elastic system or spring mass system.
6 - Question
The mass spring system has ________ degrees of freedom.
a) 4
b) 3
c) 6
d) 5
View Answer
Answer: c
Explanation: The elastic spring system has six natural frequencies and thus has six degrees of freedom.
7 - Question
The time for one complete oscillation of the mass in the spring system is called _________
a) Amplitude
b) Time period
c) Free period
d) Frequency interval
View Answer
Answer: c
Explanation: The time for one complete oscillation of the mass is called the free period and the distance up or down from the equilibrium position is called the amplitude.
8 - Question
Which of the following expression is called the equation of motion?
a) fn = k / m
b) z + ωn2 z = 0
c) m z + ωn2 z = 0
d) k z + k / m = 0
View Answer
Answer: b
Explanation: The equation of motion is given by the following formula
z + ωn2 z = 0
Where, m = mass of the vibrating body
Z = acceleration
ωn = natural frequency of the system.
9 - Question
For an oscillatory machine, the force can be expressed as _________
a) Cosine function and Sine function
b) Cosec function
c) None of the mentioned
d) All of the mentioned
View Answer
Answer: a
Explanation: Generally for an oscillatory machine (where the machinery vibrates because an unbalanced rotational force exists), the force can be expressed as a sine or cosine function, such as F0sinωt.