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Code No: A107412101 Set No. 1JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

IV B.Tech. I Sem., I Mid-Term Examinations, September – 2011VIBRATIONS AND STRUCTURAL DYNAMICS

Objective ExamName: ______________________________ Hall Ticket No.

Answer All Questions. All Questions Carry Equal Marks.Time: 20 Min. Marks: 20.

I Choose the correct alternative: 1. When the magnitude of natural frequency and forced frequency is same, then the vibrating system

is said to be under ____ condition [ ]

(A) Damping (B) resonance (C) un-damped (D) none

2. The interference between two waves of slightly different frequencies moving along the same

straight line in the same direction is known as [ ]

(A) Amplitude  (B) Beats Phenomena (C) Critical damping (D) none 3. The amount of external excitation is not known by magnitude in a vibrating system, then such

vibrations are called [ ]

(A) Forced vibrations (B) Linear vibrations (C) torsional vibrations (D) Random vibrations

4. The sum of the kinetic energy and potential energy of a vibrating system is in energy method 

[ ](A) variable (B) constant (C) zero (D) none

5. Microscopic slip occurs on the interfaces of machine elements which causes dissipation of 

vibrational energy is called [ ](A) Coulomb damping (B) structural damping (C) slip damping (D) Viscous damping

6. The critical damping constant ( Cc )is given by the formula [ ](A) 2√km (B) 2√k/m (C) √k/m (D) k/2√m

7. The equation of motion for a spring mass damped system under forced vibrations is equal to [ ](A)Coulomb damping (B) structural damping (C) slip damping (D) Viscous damping

8. A vibrometer is also known as _________ frequency transducer. [ ]

(A) Medium (B) None (C) High (D) Low.

9. The amplitude of vibration at resonance condition is [ ]

(A) Minimum (B) Maximum (C) Unaltered (D) none.

10. If two springs having the spring constants 100 N/m and 200 N/m, then the equivalent stiffness in

series is given by [ ](A) 100 / 3 (B) 200 / 3 (C) 400 / 3 (D) 500 / 3

Cont….2

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Code No: A107412101 :2: Set No. 1

II Fill in the blanks.

11. The minimum number of independent coordinates required to specify the motion of a vibrating

 body at any instant is known as _________ of the system.

12. According to the D’Alembert’s principle, the sum of inertial forces and external forces is equal to _______.

13. The parameter that can be found by bifilar suspension method is ____________.

14. At resonance condition, the equation of vibrometer is transformed into the formula ______.

15. In critical damping, the time taken for recoil is ________ times of the cycle time.

16. The vibration measuring instruments are designed based on __________ motion approach.

17. The speeds of rotating shafts at which the resonance occurs is known as _________ speed.

18. The condition for uncoupled differential equations where the translator and angular motion canexist independently is known as _______ coupling.

19. In continuous system the number of degree of freedom is equal to _________.

20. The lowest Eigen value of a vibrating system is known as its __________ natural frequency.

-oOo-

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Code No: A107412101 Set No. 2JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

IV B.Tech. I Sem., I Mid-Term Examinations, September – 2011VIBRATIONS AND STRUCTURAL DYNAMICS

Objective ExamName: ______________________________ Hall Ticket No.

Answer All Questions. All Questions Carry Equal Marks.Time: 20 Min. Marks: 20.

I Choose the correct alternative: 1. The sum of the kinetic energy and potential energy of a vibrating system is in energy method [ ]

(A) variable (B) constant (C) zero (D) none

2. Microscopic slip occurs on the interfaces of machine elements which causes dissipation of 

vibrational energy is called [ ]

 (A) Coulomb damping (B) structural damping (C) slip damping (D) Viscous damping

3. The critical damping constant ( Cc )is given by the formula [ ]

(A) 2√km (B) 2√k/m (C) √k/m (D) k/2√m

4. The equation of motion for a spring mass damped system under forced vibrations is equal to [ ]

(A)Coulomb damping (B) structural damping (C) slip damping (D) Viscous damping

5. A vibrometer is also known as _________ frequency transducer. [ ](A) Medium (B) None (C) High (D) Low.

6. The amplitude of vibration at resonance condition is [ ](A) Minimum (B) Maximum (C) Unaltered (D) none.

7. If two springs having the spring constants 100 N/m and 200 N/m, then the equivalent stiffness in

series is given by [ ](A) 100 / 3 (B) 200 / 3 (C) 400 / 3 (D) 500 / 3

8. When the magnitude of natural frequency and forced frequency is same, then the vibrating systemis said to be under ____ condition [ ]

(A) Damping (B) resonance (C) un-damped (D) none

9. The interference between two waves of slightly different frequencies moving along the same

straight line in the same direction is known as [ ]

(A) Amplitude (B) Beats Phenomena (C) Critical damping (D) none

10. The amount of external excitation is not known by magnitude in a vibrating system, then such

vibrations are called [ ]

(A) Forced vibrations (B) Linear vibrations (C) torsional vibrations (D) Random vibrations

Cont….2

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Code No: A107412101 :2: Set No. 2

II Fill in the blanks.

11. At resonance condition, the equation of vibrometer is transformed into the formula ______.

12. In critical damping, the time taken for recoil is ________ times of the cycle time.

13. The vibration measuring instruments are designed based on __________ motion approach.

14. The speeds of rotating shafts at which the resonance occurs is known as _________ speed.

15. The condition for uncoupled differential equations where the translator and angular motion canexist independently is known as _______ coupling.

16. In continuous system the number of degree of freedom is equal to _________.

17. The lowest Eigen value of a vibrating system is known as its __________ natural frequency.

18. The minimum number of independent coordinates required to specify the motion of a vibrating body at any instant is known as _________ of the system.

19. According to the D’Alembert’s principle, the sum of inertial forces and external forces is equal to _______.

20. The parameter that can be found by bifilar suspension method is ____________.

-oOo-

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Code No: A107412101 Set No. 3JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

IV B.Tech. I Sem., I Mid-Term Examinations, September – 2011VIBRATIONS AND STRUCTURAL DYNAMICS

Objective ExamName: ______________________________ Hall Ticket No.

Answer All Questions. All Questions Carry Equal Marks.Time: 20 Min. Marks: 20.

I Choose the correct alternative: 1. The critical damping constant ( Cc )is given by the formula [ ]

(A) 2√km (B) 2√k/m (C) √k/m (D) k/2√m

2. The equation of motion for a spring mass damped system under forced vibrations is equal to [ ](A)Coulomb damping (B) structural damping (C) slip damping (D) Viscous damping

3. A vibrometer is also known as _________ frequency transducer. [ ](A) Medium (B) None (C) High (D) Low.

4. The amplitude of vibration at resonance condition is [ ]

(A) Minimum (B) Maximum (C) Unaltered (D) none.

5. If two springs having the spring constants 100 N/m and 200 N/m, then the equivalent stiffness in

series is given by [ ]

(A) 100 / 3 (B) 200 / 3 (C) 400 / 3 (D) 500 / 3

6. When the magnitude of natural frequency and forced frequency is same, then the vibrating systemis said to be under ____ condition [ ](A) Damping (B) resonance (C) un-damped (D) none

7. The interference between two waves of slightly different frequencies moving along the samestraight line in the same direction is known as [ ]

(A) Amplitude (B) Beats Phenomena (C) Critical damping (D) none

8. The amount of external excitation is not known by magnitude in a vibrating system, then such

vibrations are called [ ]

(A) Forced vibrations (B) Linear vibrations (C) torsional vibrations (D) Random vibrations

9. The sum of the kinetic energy and potential energy of a vibrating system is in energy method [ ]

(A) variable (B) constant (C) zero (D) none

10. Microscopic slip occurs on the interfaces of machine elements which causes dissipation of 

vibrational energy is called [ ]

(A) Coulomb damping (B) structural damping (C) slip damping (D) Viscous damping

Cont….2

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Code No: A107412101 :2: Set No. 3

II Fill in the blanks.

11. The vibration measuring instruments are designed based on __________ motion approach.

12. The speeds of rotating shafts at which the resonance occurs is known as _________ speed.

13. The condition for uncoupled differential equations where the translator and angular motion canexist independently is known as _______ coupling.

14. In continuous system the number of degree of freedom is equal to _________.

15. The lowest Eigen value of a vibrating system is known as its __________ natural frequency.

16. The minimum number of independent coordinates required to specify the motion of a vibrating

 body at any instant is known as _________ of the system.

17. According to the D’Alembert’s principle, the sum of inertial forces and external forces is equal to

 _______.

18. The parameter that can be found by bifilar suspension method is ____________.

19. At resonance condition, the equation of vibrometer is transformed into the formula ______.

20. In critical damping, the time taken for recoil is ________ times of the cycle time.

-oOo-

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Code No: A107412101 Set No. 4JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

IV B.Tech. I Sem., I Mid-Term Examinations, September – 2011VIBRATIONS AND STRUCTURAL DYNAMICS

Objective ExamName: ______________________________ Hall Ticket No.

Answer All Questions. All Questions Carry Equal Marks.Time: 20 Min. Marks: 20.

I Choose the correct alternative: 1. A vibrometer is also known as _________ frequency transducer. [ ]

(A) Medium (B) None (C) High (D) Low.

2. The amplitude of vibration at resonance condition is [ ]

(A) Minimum (B) Maximum (C) Unaltered (D) none.

3. If two springs having the spring constants 100 N/m and 200 N/m, then the equivalent stiffness in

series is given by [ ](A) 100 / 3 (B) 200 / 3 (C) 400 / 3 (D) 500 / 3

4. When the magnitude of natural frequency and forced frequency is same, then the vibrating systemis said to be under ____ condition [ ]

(A) Damping (B) resonance (C) un-damped (D) none

5. The interference between two waves of slightly different frequencies moving along the samestraight line in the same direction is known as [ ]

 (A) Amplitude (B) Beats Phenomena (C) Critical damping (D) none

6. The amount of external excitation is not known by magnitude in a vibrating system, then such

vibrations are called [ ](A) Forced vibrations (B) Linear vibrations (C) torsional vibrations (D) Random vibrations

7. The sum of the kinetic energy and potential energy of a vibrating system is in energy method [ ]

(A) variable (B) constant (C) zero (D) none

8. Microscopic slip occurs on the interfaces of machine elements which causes dissipation of 

vibrational energy is called [ ](A) Coulomb damping (B) structural damping (C) slip damping (D) Viscous damping

9. The critical damping constant ( Cc )is given by the formula [ ]

(A)2√km (B) 2√k/m (C) √k/m (D) k/2√m

10. The equation of motion for a spring mass damped system under forced vibrations is equal to [ ]

(A)Coulomb damping (B) structural damping (C) slip damping (D) Viscous damping

Cont….2

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Code No: A107412101 :2: Set No. 4

II Fill in the blanks.

11. The condition for uncoupled differential equations where the translator and angular motion can

exist independently is known as _______ coupling.

12. In continuous system the number of degree of freedom is equal to _________.

13. The lowest Eigen value of a vibrating system is known as its __________ natural frequency.

14. The minimum number of independent coordinates required to specify the motion of a vibrating

 body at any instant is known as _________ of the system.

15. According to the D’Alembert’s principle, the sum of inertial forces and external forces is equal to _______.

16. The parameter that can be found by bifilar suspension method is ____________.

17. At resonance condition, the equation of vibrometer is transformed into the formula ______.

18. In critical damping, the time taken for recoil is ________ times of the cycle time.

19. The vibration measuring instruments are designed based on __________ motion approach.

20. The speeds of rotating shafts at which the resonance occurs is known as _________ speed.

-oOo-