Deck 2: Simple Harmonic Motion, Spring-Mass-Damper System, and Shaft Vibration

Question 1

The velocity of a particle moving with simple harmonic motion is _______ at the mean position.

A)Zero
B)Minimum
C)Maximum
D)None of the mentioned

Answer 1

Maximum

Question 2

The maximum acceleration of a particle moving with simple harmonic motion is ____.

A)?
B)?.r
C)? / 2 ?
D)2 ? / ?

Answer 2

?.r

Question 3

At the mean position, the potential energy of the system is _______.

A)Zero
B)Minimum
C)Maximum
D)None of the mentioned

Answer 3

Zero

Question 4

In a spring-mass-damper system, which of the following force is considered?

A)Spring force
B)Damping force
C)Accelerating force
D)All of the above

Question 5

Frequency is equal to ______.

A)Time period
B)1/time period
C)? * time period
D)? /time period

Question 6

When the body vibrates under the influence of external force, then the body is said to be under ___________ .

A)Free vibrations
B)Natural vibrations
C)Forced vibrations
D)Damped vibrations

Question 7

A vertical spring-mass system has a mass of 0.5 kg and an initial deflection of 0.2 cm. Find the spring stiffness.

A)345 N/m
B)245 N/m
C)3452 N/m
D)2452 N/m

Question 8

A system has a mass of 0.5 kg and spring stiffness of 2452 N/m. Find the natural frequency of the system.

A)5.14 Hz
B)9.14 Hz
C)11.14 Hz
D)28.14 Hz

Question 9

What is meant by node point?

A)The point at which amplitude of vibration is maximum
B)The point at which amplitude of vibration is minimum
C)The point at which amplitude of vibration is zero
D)None of the above

Question 10

The motion of a system executing harmonic motion with one natural frequency is known as _______

A)principal mode of vibration
B)natural mode of vibration
C)both a. and b.
D)none of the above

Question 11

Which of the following statements is/are true?

A)Torsional vibrations do not occur in a three rotor system, if rotors rotate in same direction
B)Shaft vibrates with maximum frequency when rotors rotate in same direction
C)Zero node behavior is observed in rotors rotating in opposite direction
D)All of the above

Question 12

In the diagram shown below, if rotor X and rotor Z rotate in same direction and rotor Y rotates in opposite direction, then specify the type of node vibration.

A)Three node vibration
B)Two node vibration
C)Single node vibration
D)None of the above

Question 13

What is the total number of nodes formed in a three rotor system if the rotors at one of the ends and the one in the middle rotate in the

A)0
B)1
C)2
D)3

Question 14

In a multi-rotor system of torsional vibration maximum number of nodes that can occur is:

A)Two
B)Equal to the number of rotor plus one
C)Equal to the number of rotors
D)Equal to the number of rotors minus one

Question 15

During torsional vibration of a shaft, the node is characterized by

A)Maximum angular velocity
B)Maximum angular displacement
C)Maximum angular acceleration
D)Zero angular displacement

Question 16

The mass moment of inertia of the two motors in a two rotor system are 100 kgm2 and 10 kgm2 the length of the shaft of uniform

A)80 cm
B)90 cm
C)100 cm
D)110 cm

Question 17

What is the number of nodes in a shaft carrying three rotors?

A)zero
B)2
C)3
D)4

Question 18

Consider the following statements: Two rotors mounted on a single shaft can be considered to be equivalent to a geared-shaft system having two rotors provided
1) The kinetic energy of the equivalent system is equal to that of the original system.
2) The strain energy of the equivalent system is equal to that of the original system.
3) The shaft diameters of the two systems are equal. Which of these statements are correct?

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

Question 19

Two rotors A and B are connected to the two ends of a shaft of uniform diameter. The mass moment of inertia of rotor A about the

A)1/5 m
B)4/5 m
C)1/25 m
D)16/25 m

Question 20

Which one of the following is correct for a shaft carrying two rotors at its ends?

A)It has no node
B)It has one node
C)It has two nodes
D)It has three nodes

Question 21

A system, which is free from both the ends

A)Definite system
B)Semidefinite system
C)Both a and b
D)None of the above

Question 22

A system, which is fixed from one end or both the ends is referred as

A)Definite system
B)Semidefinite system
C)Both a and b
D)None of the above

Question 23

In a system with different shaft parameters, the longest shaft is taken for calculations.

Question 24

In a system with different shaft parameters ------------- is taken which depends on the length and diameters of each shaft.

A)Equivalent shaft length
B)length of first shaft
C)lrngth of intermediate shaft
D)None of these

Question 25

From the following data, calculate the location of node from the left end of shaft (l1).l1=0.6m, l2=0.5m, l3=0.4m d1=0.095m, d2=0.06m, d3=0.05m Ma = 900 Kg, Mb = 700 Kg ka = 0.85m, kb = 0.55m

A)0.855m
B)0.795m
C)0.695m
D)0.595m