| 1. | Which type of vibrations are also known as transient vibrations? |
| A. | Undamped vibrations |
| B. | Damped vibrations |
| C. | Torsional vibrations |
| D. | Transverse vibrations |
| Answer» B. Damped vibrations | |
| 2. | During transverse vibrations, shaft is subjected to which type of stresses? |
| A. | Tensile stresses |
| B. | Torsional shear stress |
| C. | Bending stresses |
| D. | All of the above |
| Answer» C. Bending stresses | |
| 3. | What are deterministic vibrations? |
| A. | Vibrations caused due to known exciting force |
| B. | Vibrations caused due to unknown exciting force |
| C. | Vibrations which are aperiodic in nature |
| D. | None of the above |
| Answer» A. Vibrations caused due to known exciting force | |
| 4. | Which of the following vibrations are classified according to magnitude of actuating force? |
| A. | Torsional vibrations |
| B. | Deterministic vibrations |
| C. | Transverse vibrations |
| D. | All of the above |
| Answer» B. Deterministic vibrations | |
| 5. | In which type of vibrations, amplitude of vibration goes on decreasing every cycle? |
| A. | Damped vibrations |
| B. | Undamped vibrations |
| C. | Both a. and b. |
| D. | None of the above |
| Answer» A. Damped vibrations | |
| 6. | The resonant frequency of a mass-spring system depends upon ________ |
| A. | stiffness |
| B. | surface density |
| C. | depth of air space |
| D. | all of the above |
| Answer» D. all of the above | |
| 7. | Calculate equivalent stiffness of the spring for the system shown below, which has spring stiffness of 3000 N/m |
| A. | 1000 N/m |
| B. | 2250 N/m |
| C. | 2000 N/m |
| D. | None of the above |
| Answer» B. 2250 N/m | |
| 8. | Which of the following is incorrect regarding inertia force? |
| A. | Imaginary force |
| B. | Acts upon a rigid body |
| C. | Brings the body to equilibrium |
| D. | Same direction as of accelerating force |
| Answer» D. Same direction as of accelerating force | |
| 9. | D-Alembert’s principle is used for which of the following? |
| A. | Change static problem into a dynamic problem |
| B. | Change dynamic problem to static problem |
| C. | To calculate moment of inertia of rigid bodies |
| D. | To calculate angular momentum of a system of masses |
| Answer» B. Change dynamic problem to static problem | |
| 10. | Determine logarithmic decrement, if the amplitude of a vibrating body reduces to 1/6th in two cycles. |
| A. | 0.223 |
| B. | 0.8958 |
| C. | 0.389 |
| D. | None of the above |
| Answer» B. 0.8958 | |
| 11. | Calculate logarithmic decrement if damping factor is 0.33. |
| A. | 1.36 |
| B. | 3.23 |
| C. | 5.16 |
| D. | 2.19 |
| Answer» D. 2.19 | |
| 12. | In damped free vibrations, which parameters indicate vibrations? |
| A. | Natural frequency |
| B. | Rate of decay of amplitude |
| C. | Both a. and b. |
| D. | None of the above |
| Answer» B. Rate of decay of amplitude | |
| 13. | What is meant by critical damping coefficient? |
| A. | Frequency of damped free vibrations is less than zero |
| B. | The motion is aperiodic in nature |
| C. | Both a. and b. |
| D. | None of the above |
| Answer» B. The motion is aperiodic in nature | |
| 14. | Which of the following relations is true for viscous damping? |
| A. | Force α relative displacement |
| B. | Force α relative velocity |
| C. | Force α (1 / relative velocity) |
| D. | None of the above |
| Answer» B. Force α relative velocity | |
| 15. | Which among the following is the value of static deflection (δ) for a fixed beam with central point load? |
| A. | (Wl3) /(192 EI) |
| B. | (Wl2) /(192 EI) |
| C. | (Wl3) /(384 EI) |
| D. | None of the above |
| Answer» A. (Wl3) /(192 EI) | |
| 16. | According to which method, maximum kinetic energy at mean position is equal to maximum potential energy at extreme position? |
| A. | Energy method |
| B. | Rayleigh’s method |
| C. | Equilibrium method |
| D. | All of the above |
| Answer» B. Rayleigh’s method | |
| 17. | 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 |
| Answer» C. both a. and b. | |
| 18. | Fluid resistance causes damping which is known as ______ |
| A. | Resistance damping |
| B. | Fluid damping |
| C. | Viscous damping |
| D. | Liquid damping |
| Answer» C. Viscous damping | |
| 19. | In which direction does the accelerating force acts? |
| A. | Opposite to the motion |
| B. | Along the motion |
| C. | Perpendicular to motion |
| D. | Variable |
| Answer» B. Along the motion | |
| 20. | The time interval after which the motion is repeated itself is known as ___________ . |
| A. | Time period |
| B. | Cycle |
| C. | Frequency |
| D. | Isolation |
| Answer» A. Time period | |
| 21. | Frequency of vibrations is usually expressed in |
| A. | Number of cycles per hour |
| B. | Number of cycles per minute |
| C. | Number of cycles per second |
| D. | None of these |
| Answer» C. Number of cycles per second | |
| 22. | The motion completed during one time period is known as _______. |
| A. | Period of vibration |
| B. | Cycle |
| C. | Frequency |
| D. | All of the above |
| Answer» B. Cycle | |
| 23. | Which of the following is a type of free vibration? |
| A. | Longitudinal vibrations |
| B. | Transverse vibrations |
| C. | Torsional vibrations |
| D. | A, B and C |
| Answer» D. A, B and C | |
| 24. | In a spring-mass system, which of the following force is not considered? |
| A. | Spring force |
| B. | Damping force |
| C. | Accelerating force |
| D. | A and B |
| Answer» B. Damping force | |
| 25. | The periodic time is given by _______. |
| A. | ω / 2 π |
| B. | 2 π / ω |
| C. | 2 π × ω |
| D. | π/ω |
| Answer» B. 2 π / ω | |
| 26. | 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» C. Maximum | |
| 27. | The maximum acceleration of a particle moving with simple harmonic motion is ____. |
| A. | ω |
| B. | ω.r |
| C. | ω / 2 π |
| D. | 2 π / ω |
| Answer» B. ω.r | |
| 28. | At the mean position, the potential energy of the system is _______. |
| A. | Zero |
| B. | Minimum |
| C. | Maximum |
| D. | None of the mentioned |
| Answer» A. Zero | |
| 29. | 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 |
| Answer» D. All of the above | |
| 30. | Frequency is equal to ______. |
| A. | Time period |
| B. | 1/time period |
| C. | ω * time period |
| D. | ω /time period |
| Answer» B. 1/time period | |
| 31. | 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 |
| Answer» C. Forced vibrations | |
| 32. | 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 |
| Answer» D. 2452 N/m | |
| 33. | 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 |
| Answer» C. 11.14 Hz | |
Chapter: Free Vibration
| 34. | 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 |
| Answer» C. The point at which amplitude of vibration is zero | |
| 35. | 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 |
| Answer» C. both a. and b. | |
| 36. | 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 |
| Answer» A. Torsional vibrations do not occur in a three rotor system, if rotors rotate in same direction | |
| 37. | 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 |
| Answer» B. Two node vibration | |
| 38. | 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 |
| Answer» B. 1 | |
| 39. | 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 |
| Answer» D. Equal to the number of rotors minus one | |
| 40. | 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 |
| Answer» D. Zero angular displacement | |
| 41. | 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 |
| Answer» C. 100 cm | |
| 42. | What is the number of nodes in a shaft carrying three rotors? |
| A. | zero |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» B. 2 | |
| 43. | 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 |
| Answer» A. 1, 2 and 3 | |
| 44. | 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 |
| Answer» A. 1/5 m | |
| 45. | 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 |
| Answer» B. It has one node | |
| 46. | 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 |
| Answer» B. Semidefinite system | |
| 47. | 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 |
| Answer» A. Definite system | |
| 48. | In a system with different shaft parameters, the longest shaft is taken for calculations. |
| A. | TRUE |
| B. | FALSE |
| Answer» B. FALSE | |
| 49. | 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 |
| Answer» A. Equivalent shaft length | |
| 26. | 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» C. Maximum | |
| 27. | The maximum acceleration of a particle moving with simple harmonic motion is ____. |
| A. | ω |
| B. | ω.r |
| C. | ω / 2 π |
| D. | 2 π / ω |
| Answer» B. ω.r | |
| 28. | At the mean position, the potential energy of the system is _______. |
| A. | Zero |
| B. | Minimum |
| C. | Maximum |
| D. | None of the mentioned |
| Answer» A. Zero | |
| 29. | 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 |
| Answer» D. All of the above | |
| 30. | Frequency is equal to ______. |
| A. | Time period |
| B. | 1/time period |
| C. | ω * time period |
| D. | ω /time period |
| Answer» B. 1/time period | |
| 31. | 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 |
| Answer» C. Forced vibrations | |
| 32. | 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 |
| Answer» D. 2452 N/m | |
| 33. | 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 |
| Answer» C. 11.14 Hz | |
Chapter: Free Vibration
| 34. | 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 |
| Answer» C. The point at which amplitude of vibration is zero | |
| 35. | 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 |
| Answer» C. both a. and b. | |
| 36. | 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 |
| Answer» A. Torsional vibrations do not occur in a three rotor system, if rotors rotate in same direction | |
| 37. | 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 |
| Answer» B. Two node vibration | |
| 38. | 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 |
| Answer» B. 1 | |
| 39. | 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 |
| Answer» D. Equal to the number of rotors minus one | |
| 40. | 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 |
| Answer» D. Zero angular displacement | |
| 41. | 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 |
| Answer» C. 100 cm | |
| 42. | What is the number of nodes in a shaft carrying three rotors? |
| A. | zero |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» B. 2 | |
| 43. | 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 |
| Answer» A. 1, 2 and 3 | |
| 44. | 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 |
| Answer» A. 1/5 m | |
| 45. | 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 |
| Answer» B. It has one node | |
| 46. | 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 |
| Answer» B. Semidefinite system | |
| 47. | 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 |
| Answer» A. Definite system | |
| 48. | In a system with different shaft parameters, the longest shaft is taken for calculations. |
| A. | TRUE |
| B. | FALSE |
| Answer» B. FALSE | |
| 49. | 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 |
| Answer» A. Equivalent shaft length | |
| 51. | For a vibration system having different shaft parameters, calculate which of the following cannot be the diameter of the equivalent shaft if the diameters of shafts in m are: 0.05, 0.06, 0.07. |
| A. | 0.05 |
| B. | 0.06 |
| C. | 0.07 |
| D. | 0.08 |
| Answer» D. 0.08 | |
| 52. | A single cylinder oil engine works with a three rotor system, the shaft length is 2.5m and 70mm in diameter, the middle rotor is at a distance 1.5m from one end. Calculate the free torsional vibration frequency for a single node system in Hz if the mass moment of inertia of rotors in Kg-m2 are: 0.15, 0.3 and 0.09. C=84 kN/mm2 |
| A. | 171 |
| B. | 181 |
| C. | 191 |
| D. | 201 |
| Answer» A. 171 | |
| 53. | At a nodal point in the shaft, the frequency of vibration is _________ |
| A. | Zero |
| B. | Double than at the ends |
| C. | Minimum |
| D. | Maximum |
| Answer» A. Zero | |
| 54. | For a gearing system, the equivalent system is made consisting of two rotors. How many nodes will this new equivalent system will have? |
| A. | 0 |
| B. | 1 |
| C. | 2 |
| D. | 3 |
| Answer» B. 1 | |
| 55. | In a gearing system, pump speed is one third of the motor. Shaft from motor is 6 cm in diameter and 30cm long, the impellar shaft is 10cm diameter and 60cm long. Mass moment of inertia is 1500 Kgm2, C = 80Gn/m2. Neglecting the inertia of shaft and gears calculate the frequency of free torsional vibrations in Hz. |
| A. | 4.7 |
| B. | 5.7 |
| C. | 4.5 |
| D. | 5.5 |
| Answer» A. 4.7 | |
| 56. | When inertia of gearing is taken into consideration, then which of the following should be taken into account. |
| A. | Addition of rotor |
| B. | Addition of gear |
| C. | Addition of shaft |
| D. | Addition of pump |
| Answer» A. Addition of rotor | |
| 57. | Consider P and Q as the shaft having two rotors at the end of it, what is the point N known as in the given figure? |
| A. | Node |
| B. | Elastic point |
| C. | Inelastic point |
| D. | Breaking point |
| Answer» A. Node | |
| 58. | For occurrence of free torsional vibration which of the condition is necessary? |
| A. | Rotors moving in same direction |
| B. | Rotors having same frequency |
| C. | Rotors having different frequency |
| D. | Rotors rotate in the same sense |
| Answer» B. Rotors having same frequency | |
| 59. | n the given figure if N is the node then NQ acts as which of the following system? |
| A. | Single rotor system |
| B. | Two rotor system |
| C. | Three rotor system |
| D. | Four rotor system |
| Answer» A. Single rotor system | |
| 60. | Keeping the mass moment of inertia of both the shafts in a two rotor system same, if the length of one shaft is doubled what should be the effect on the length of other shaft? |
| A. | Doubled |
| B. | Halved |
| C. | Constant |
| D. | increased to 4 times |
| Answer» A. Doubled | |
| 61. | In the figure given below, the points N1 and N2 are known as_______ |
| A. | Nodes |
| B. | Elastic points |
| C. | Inelastic points |
| D. | Breaking points |
| Answer» A. Nodes | |
| 62. | In which of the following condition torsional vibration will not take place, considering 3 rotors A, B and C. A is rotating in clockwise direction. |
| A. | B in clockwise C in anticlockwise |
| B. | C in clockwise B in anticlockwise |
| C. | B and C in clockwise |
| D. | B and C in anticlockwise |
| Answer» C. B and C in clockwise | |
| 63. | For occurrence of free torsional vibration in a three rotor system which of the condition is necessary? |
| A. | Rotors moving in same direction |
| B. | Rotors having same frequency |
| C. | Rotors having different frequency |
| D. | Rotors rotate in the same sense |
| Answer» B. Rotors having same frequency | |
| 64. | A vertical circular disc is supported by a horizontal stepped shaft as shown below. Determine equivalent length of shaft when equivalent diameter is 20 mm. |
| A. | 1.559 m |
| B. | 0.559 m |
| C. | 0.633 m |
| D. | None of the above |
| Answer» B. 0.559 m | |
| 65. | In a three rotor system, for the middle rotor, if the stiffness of both the length either side of the rotor is increased to two times what will |
| A. | Remains constant |
| B. | Decreases by two times |
| C. | Increases by two times |
| D. | Increases by 4 times |
| Answer» C. Increases by two times | |
| 66. | A single cylinder oil engine works with a three rotor system, the shaft length is 2.5m and 70mm in diameter, the middle rotor is at a distance 1.5m from one end. Calculate the free torsional vibration frequency for a two node system in Hz if the mass moment of inertia of rotors in Kg-m2 are: 0.15, 0.3 and 0.09. C=84 kN/mm2 |
| A. | 257 |
| B. | 281 |
| C. | 197 |
| D. | 277 |
| Answer» D. 277 | |
| 67. | Increasing which of the following factor would result in increase of free torsional vibration? |
| A. | Radius of gyration |
| B. | Mass moment of inertia |
| C. | Polar moment of inertia |
| D. | Length |
| Answer» C. Polar moment of inertia | |
| 68. | The frequency of the free torsional vibration depends on……. |
| A. | number of rotors |
| B. | the number of nodes |
| C. | Both a and b |
| D. | Only b |
| Answer» C. Both a and b | |
| 69. | For a two rotor system, the mass moment of inertia of one shaft(A) is twice the other(B), then what is the relation between the length of the shafts. |
| A. | 2L(A) = L(B) |
| B. | L(A) = 2L(B) |
| C. | L(A) = L(B) |
| D. | 2L(A) = 3L(B) |
| Answer» A. 2L(A) = L(B) | |
Chapter: Balancing
| 70. | 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 |
| Answer» A. Direction changes with rotation | |
| 71. | If the unbalanced system is not set right then. |
| A. | Static forces develop |
| B. | Dynamic forces develop |
| C. | Tangential forces develop |
| D. | Radial forces develop |
| Answer» A. Static forces develop | |
| 72. | 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 |
| Answer» A. Bend the shaft | |
| 73. | In a revolving rotor, the centrifugal force remains balanced as long as the centre of the mass of the rotor lies ___________ |
| A. | Below the axis of shaft |
| B. | On the axis of the shaft |
| C. | Above the axis of shaft |
| D. | Away from the axis of shaft |
| Answer» B. On the axis of the shaft | |
| 74. | 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 |
| Answer» D. Inertia forces | |
| 76. | In balancing of single-cylinder engine, the rotating unbalance is ____________ |
| A. | completely made zero and so also the reciprocating unbalance |
| B. | completely made zero and the reciprocating unbalance is partially reduced |
| C. | partially reduced and the reciprocating unbalance is completely made zero |
| D. | partially reduced and so also the reciprocating unbalance |
| Answer» B. completely made zero and the reciprocating unbalance is partially reduced | |
| 77. | Let the disturbing mass be 100 kg and the radius of rotation be 10 cm and the rotation speed be 50 rad/s, then calculate the centrifugal force in kN. |
| A. | 50 |
| B. | 25 |
| C. | 50000 |
| D. | 25000 |
| Answer» B. 25 | |
| 78. | Which of the following statement is correct? |
| A. | In any engine, 100% of the reciprocating masses can be balanced dynamically |
| B. | In the case of balancing of multicylinder engine, the value of secondary force is higher than the value of the primary force |
| C. | In the case of balancing of multimass rotating systems, dynamic balancing can be directly started without static balancing done to the system |
| D. | none of the mentioned |
| Answer» C. In the case of balancing of multimass rotating systems, dynamic balancing can be directly started without static balancing done to the system | |
| 79. | If all the masses are in one plane, then what is the maximum no. of masses which can be placed in the same plane? |
| A. | 3 |
| B. | 4 |
| C. | 6 |
| D. | No limitation |
| Answer» D. No limitation | |
| 80. | Which of the following statements is correct about the balancing of a mechanical system? |
| A. | If it is under static balance, then there will be dynamic balance also |
| B. | If it is under dynamic balance, then there will be static balance also |
| C. | Both static as well as dynamic balance have to be achieved separately |
| D. | None of the mentioned |
| Answer» C. Both static as well as dynamic balance have to be achieved separately | |
| 81. | In a locomotive, the ratio of the connecting rod length to the crank radius is kept very large in order to |
| A. | minimize the effect of primary forces |
| B. | minimize the effect of secondary forces |
| C. | have perfect balancing |
| D. | start the locomotive conveniently |
| Answer» B. minimize the effect of secondary forces | |
| 82. | Secondary forces in reciprocating mass on engine frame are |
| A. | of same frequency as of primary forces |
| B. | twice the frequency as of primary forces |
| C. | four times the frequency as of primary forces |
| D. | none of the mentioned |
| Answer» B. twice the frequency as of primary forces | |
| 83. | For a V-twin engine, which of the following means can be used to balance the primary forces? |
| A. | Revolving balance mass |
| B. | Rotating balance mass |
| C. | Reciprocating balance mass |
| D. | By the means of secondary forces |
| Answer» A. Revolving balance mass | |
| 84. | The primary unbalanced force is maximum when the angle of inclination of the crank with the line of stroke is |
| A. | 0° |
| B. | 90° |
| C. | 180° |
| D. | 360° |
| Answer» C. 180° | |
| 85. | From the following data of a 60 degree V-twin engine, determine the minimum value for primary forces in newtons:Reciprocating mass per cylinder = 1.5 Kg Stroke length = 10 cm Length of connecting rod = 25 cm Engine speed = 2500 rpm |
| A. | 7711 |
| B. | 4546 |
| C. | 2570 |
| D. | 8764 |
| Answer» C. 2570 | |
| 86. | From the following data of a 60 degree V-twin engine, determine the maximum value for primary forces in newtons:Reciprocating mass per cylinder = 1.5 Kg Stroke length = 10 cm Length of connecting rod = 25 cm Engine speed = 2500 rpm |
| A. | 7711 |
| B. | 4546 |
| C. | 2570 |
| D. | 8764 |
| Answer» A. 7711 | |
| 87. | In the given figure, m1=10 Kg, m2=30Kg and m=50 Kg, if r=0.3m, l=1m, find l2 = 0.5m, find r1 in m. |
| A. | 1.5 |
| B. | 0.75 |
| C. | 3 |
| D. | 6 |
| Answer» B. 0.75 | |
| 88. | 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, |
| A. | 201.48 |
| B. | 200.32 |
| C. | 210.34 |
| D. | 202.88 |
| Answer» A. 201.48 | |
| 89. | Which of the following statements are associated with complete dynamic balancing of rotating systems? 1. Resultant couple due to all inertia forces is zero. 2. Support reactions due to forces are zero but not due to couples . 3. The system is automatically statically balanced. 4. Centre of masses of the system lies on the axis of rotation. |
| A. | 1, 2, 3 and 4 |
| B. | 1, 2, and 3 only |
| C. | 2, 3 and 4 only |
| D. | 1, 3 and 4 only |
| Answer» D. 1, 3 and 4 only | |
| 90. | A V-twin engine has the cylinder axes at 90 degrees and the connecting rods operate a common crank. The reciprocating mass per cylinder is 11.5 kg and the crank radius is 7.5 cm. The length of the connecting rod is 0.3 m. If the engine is rotating at the speed is 500 r.p.m. What is the value of maximum resultant secondary force in Newtons? |
| A. | 736 |
| B. | 836 |
| C. | 936 |
| D. | 636 |
| Answer» B. 836 | |
| 91. | Let the centrifugal force in kN be 25 and the radius of rotation be 20 cm and the rotation speed be 50 rad/s, then calculate the mass defect in Kg. |
| A. | 50 |
| B. | 25 |
| C. | 50000 |
| D. | 25000 |
| Answer» A. 50 | |
| 92. | In a multicylinder inline engine, each imaginary secondary crank with a mass attached to the crankpin is inclined to the line of stroke at which angle? |
| A. | Twice the angle of crank |
| B. | Half the angle of crank |
| C. | Thrice the angle of crank |
| D. | Four times the angle of crank |
| Answer» A. Twice the angle of crank | |
| 93. | In order to achieve stability, the sum of secondary forces and secondary couples must be ——- and their respective polygons must be ……… |
| A. | Zero, Closed |
| B. | one, Open |
| C. | Zero, open |
| D. | one, closed |
| Answer» A. Zero, Closed | |
| 94. | For the secondary balancing of the engine, which of the condition is necessary? |
| A. | Secondary force polygon must be close |
| B. | Secondary force polygon must be open |
| C. | Primary force polygon must be close |
| D. | Primary force polygon must be open |
| Answer» A. Secondary force polygon must be close | |
| 95. | The numerical values of the secondary forces and secondary couples couples may be obtained by considering the ___________ |
| A. | Revolving mass |
| B. | Reciprocating mass |
| C. | Translating mass |
| D. | Rotating mass |
| Answer» A. Revolving mass | |
| 96. | Which of the following is the correct expression for secondary force? |
| A. | m𝜔^2r.cos2θ/n |
| B. | m 𝜔^2r.sin2θ/n |
| C. | m𝜔^2r.tan2θ/n |
| D. | m𝜔^2r.cosθ/n |
| Answer» A. m𝜔^2r.cos2θ/n | |
| 97. | A V-twin engine has the cylinder axes at 90 degrees and the connecting rods operate a common crank. The reciprocating mass per cylinder is 23 kg and the crank radius is 7.5 cm. The length of the connecting rod is 0.3 m. If the engine is rotating at the speed is 500 r.p.m. What is the value of maximum resultant secondary force in Newtons? |
| A. | 7172 |
| B. | 1672 |
| C. | 1122 |
| D. | 1272 |
| Answer» B. 1672 | |
| 98. | A V-twin engine has the cylinder axes at 90 degrees and the connecting rods operate a common crank. The reciprocating mass per cylinder is 34.5 kg and the crank radius is 7.5 cm. The length of the connecting rod is 0.3 m. If the engine is rotating at the speed is 500 r.p.m. What is the value of maximum resultant secondary force in kN? |
| A. | 2.238 |
| B. | 2.508 |
| C. | 2.754 |
| D. | 2.908 |
| Answer» B. 2.508 | |
| 99. | From the given data, find the balancing mass in Kg 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. | 116 |
| B. | 58 |
| C. | 232 |
| D. | 140 |
| Answer» A. 116 | |
| 101. | From the given data, calculate the unbalanced centrifugal force in N s2 Distance from shaft = 0.2 m Mass = 100 kg Rotating speed = 1000 rpm. |
| A. | 20 |
| B. | 2×10^7 |
| C. | 200 |
| D. | 20000 |
| Answer» C. 200 | |
| 102. | Let the disturbing mass be 50 Kg, with radius of rotation = 0.1m, if one of the balancing mass is 30 Kg at a radius of rotation 0.1m then find the other balancing mass situated at a distance of 0.2m. |
| A. | 80 |
| B. | 40 |
| C. | 20 |
| D. | 10 |
| Answer» D. 10 | |
| 103. | In the given figure, m1=20 Kg, m2=30Kg and m=50 Kg, if r1=0.2m and r=0.3m, l=1m, find l2. |
| A. | 0.26m |
| B. | 0.52m |
| C. | 1.04m |
| D. | 13m |
| Answer» A. 0.26m | |
Chapter: Measurement and Control of Vibration
| 104. | What is the function of frequency analyzer? |
| A. | It analysis noise signal in frequency domain into various frequency bands by magnetically separating the signal |
| B. | It analysis noise signal in frequency domain into various frequency bands by electronically separating the signal |
| C. | It analysis noise signal in frequency domain into various frequency bands by electromagnetically separating the signal |
| D. | None of the above |
| Answer» B. It analysis noise signal in frequency domain into various frequency bands by electronically separating the signal | |
| 105. | What is the function of the controller in active vibration isolation systems? |
| A. | Detect vibrations to be controlled |
| B. | Reposition the masses |
| C. | Interpret detected vibrations and execute commands |
| D. | All of the above |
| Answer» C. Interpret detected vibrations and execute commands | |
| 106. | Temperature monitoring technique uses which of the following devices to measure temperature of the machining surfaces? |
| A. | Pyrometers |
| B. | Thermocouples |
| C. | Thermometers |
| D. | All of the above |
| Answer» D. All of the above | |
| 107. | Which of the following statements is true about stroboscope? |
| A. | Stroboscope is non-contact type frequency instrument |
| B. | Stroboscope can measure frequency upto 5 Hz |
| C. | Stroboscope uses electromagnetic radiations to measure frequency |
| D. | All of the above |
| Answer» A. Stroboscope is non-contact type frequency instrument | |
| 108. | Which type of frequency measuring instrument has multiple reeds of different natural frequency to measure vibrations? |
| A. | Fullarton tachometer |
| B. | Frahm Tachometer |
| C. | Both a. and b. |
| D. | None of the above |
| Answer» B. Frahm Tachometer | |
| 109. | Which of the following instruments measure amplitude of a vibrating body? |
| A. | Vibrometers |
| B. | Seismometer |
| C. | Both a. and b. |
| D. | None of the above |
| Answer» C. Both a. and b. | |
| 110. | Which of the following vibrometers have frequency ratio (ω/ωn) << 1? |
| A. | Accelerometers |
| B. | Velometers |
| C. | Both a. and b. |
| D. | None of the above |
| Answer» A. Accelerometers | |
| 111. | Which type of monitoring system uses stroboscope to measure speed of the machine? |
| A. | Portable condition monitoring system |
| B. | Basic condition monitoring system |
| C. | Computer based condition monitoring system |
| D. | None of the above |
| Answer» B. Basic condition monitoring system | |
| 112. | Seismometer can be used to measure acceleration of any instrument only if _____ |
| A. | it’s natural frequency is high |
| B. | it generates output signal which is proportional to relative acceleration of the vibrating object |
| C. | both a. and b. |
| D. | none of the above |
| Answer» C. both a. and b. | |
| 113. | In FFT Spectrum Analyzer, the D/A converter is used to ________. |
| A. | reject unwanted signals |
| B. | sets the level of the signals to be fed to the A/D converter |
| C. | convert analog signals into digital signals |
| D. | converts digital signals into analog signals |
| Answer» D. converts digital signals into analog signals | |
| 114. | In FFT Spectrum Analyzer, the A/D converter is used to ________. |
| A. | reject unwanted signals |
| B. | sets the level of the signals to be fed to the A/D converter |
| C. | convert analog signals into digital signals |
| D. | converts digital signals into analog signals |
| Answer» C. convert analog signals into digital signals | |
| 115. | In FFT Spectrum Analyzer, the attenuator is used to ________. |
| A. | reject unwanted signals |
| B. | sets the level of the signals to be fed to the A/D converter |
| C. | convert analog signals into digital signals |
| D. | converts digital signals into analog signals |
| Answer» B. sets the level of the signals to be fed to the A/D converter | |
| 116. | In FFT Spectrum Analyzer, the filter is used to ________. |
| A. | reject unwanted signals |
| B. | sets the level of the signals to be fed to the A/D converter |
| C. | convert analog signals into digital signals |
| D. | converts digital signals into analog signals |
| Answer» A. reject unwanted signals | |
| 117. | FFT analyzer can be used to find the ___________. |
| A. | natural frequencies |
| B. | mode shapes |
| C. | both natural frequencies and mode shapes |
| D. | none of the above |
| Answer» C. both natural frequencies and mode shapes | |
| 118. | Fourier transform is a mathematical procedure to obtain the __________ of a given input signal. |
| A. | spectrum |
| B. | integration |
| C. | difference |
| D. | none of the above |
| Answer» A. spectrum | |
| 119. | In FFT Spectrum Analyzer, FFT stands for _______. |
| A. | Frequency Fourier Transform |
| B. | Fast Fourier Transmission |
| C. | Frequency Fourier Transmission |
| D. | Fast Fourier Transform |
| Answer» D. Fast Fourier Transform | |
| 120. | From the following, which one is used in an accelerometer? |
| A. | Dielectric crystals |
| B. | Piezoelectric crystals |
| C. | Optic crystals |
| D. | Diamond |
| Answer» B. Piezoelectric crystals | |
| 121. | The accelerometers are commonly used in vibration measurement due to their ___________. |
| A. | small size and low sensitivity |
| B. | the large size and high sensitivity |
| C. | the large size and low sensitivity |
| D. | small size and high sensitivity |
| Answer» D. small size and high sensitivity | |
| 122. | Which instrument is used to record building vibrations or vibrations of huge structures like railway bridges? |
| A. | Stroboscope |
| B. | Accelerometer |
| C. | Vibrometer |
| D. | None of the above |
| Answer» C. Vibrometer | |
| 123. | Vibration measuring instruments are classified on the basis of ____________. |
| A. | contact between the vibrating system and measuring instrument |
| B. | the requirement of power source |
| C. | method of measurements |
| D. | all of the above |
| Answer» D. all of the above | |
| 124. | From the following, which one is also known as low-frequency Transducer? |
| A. | Stroboscope |
| B. | Accelerometer |
| C. | Vibrometer |
| D. | None of the above |
| Answer» C. Vibrometer | |
| 126. | An accelerometer is an instrument used to measure the _________ of a vibrating body. |
| A. | displacement |
| B. | velocity |
| C. | acceleration |
| D. | all of the above |
| Answer» C. acceleration | |
| 127. | Stroboscope is used for the measurement of _________________? |
| A. | Rpm of a flywheel |
| B. | Frequency of light |
| C. | Depression of freezing point |
| D. | Liquid level under pressure |
| Answer» A. Rpm of a flywheel | |
| 128. | A seismometer is a device used to measure the ___________ of a vibrating body. |
| A. | displacement |
| B. | velocity |
| C. | acceleration |
| D. | all of the above |
| Answer» A. displacement | |
| 129. | The instruments which are used to measure the ___________ of a vibrating body are called vibration measuring instrument. |
| A. | displacement |
| B. | velocity |
| C. | acceleration |
| D. | all of the above |
| Answer» D. all of the above | |
| 130. | The accelerometer is used as a transducer to measure earthquake in Richter scale. Its design is based on the principle that ______. |
| A. | its natural frequency is very low in comparison to the frequency of vibration |
| B. | its natural frequency is very high in comparison to the frequency of vibration |
| C. | its natural frequency is equal to the frequency of vibration |
| D. | measurement of vibratory motion is without any reference point |
| Answer» C. its natural frequency is equal to the frequency of vibration | |
| 131. | Which of the following instruments measure the amplitude of a vibrating body? |
| A. | Vibrometers |
| B. | Seismometer |
| C. | Both (a) and (b) |
| D. | None of these |
| Answer» C. Both (a) and (b) | |
| 132. | Which of the following systems produce a vibration in the foundation? |
| A. | Coupled machine |
| B. | Uncoupled machine |
| C. | Balanced machine |
| D. | Unbalanced machine |
| Answer» D. Unbalanced machine | |
| 133. | What does the accelerometer measure? |
| A. | Mass |
| B. | Acceleration |
| C. | Velocity |
| D. | Distance |
| Answer» B. Acceleration | |
| 134. | Which of the following device can be used for measurement of frequency? |
| A. | Voltmeter |
| B. | Ammeter |
| C. | Stroboscope |
| D. | None of the mentioned |
| Answer» C. Stroboscope | |
| 135. | Which of the following is correct regarding isolation factor? |
| A. | Dimensionless quantity |
| B. | Has Newton as its unit |
| C. | Has joule as its Unit |
| D. | Has Hz as its unit |
| Answer» A. Dimensionless quantity | |
| 136. | If the damper is not provided and the system is in resonance, which of the following is the correct isolation factor? |
| A. | 0 |
| B. | 0.5 |
| C. | 0.25 |
| D. | Infinity |
| Answer» D. Infinity | |
Chapter: Introduction to Noise
| 137. | Which part of human ear converts sound vibrations into electrical signals |
| A. | Hammer |
| B. | Stirrup |
| C. | Tympanic membrane |
| D. | Cochlea |
| Answer» D. Cochlea | |
| 138. | Sound is measured by units that are called |
| A. | Hertz (Hz) |
| B. | Decibels (dB) |
| C. | Meters (m) |
| D. | Pascal (Pa) |
| Answer» B. Decibels (dB) | |
| 139. | ‘Eardrum’ bursts at |
| A. | 40 dB |
| B. | 80 dB |
| C. | 160 dB |
| D. | 320 dB |
| Answer» C. 160 dB | |
| 140. | The loudness of sound varies directly with the vibrating body’s |
| A. | Intensity |
| B. | Amplitude |
| C. | Pitch |
| D. | Quality |
| Answer» B. Amplitude | |
| 141. | The scale to measure the intensity level of sound is called |
| A. | Vector scale |
| B. | Measuring ruler |
| C. | Bel scale |
| D. | decibel scale |
| Answer» D. decibel scale | |
| 142. | Pitch of the sound depends upon |
| A. | Frequency |
| B. | Distance of sound |
| C. | Amplitude |
| D. | Temperature |
| Answer» A. Frequency | |
| 143. | Noise is |
| A. | An unwanted noise |
| B. | An irritant |
| C. | A source of stress |
| D. | all of the above |
| Answer» D. all of the above | |
| 144. | Following scale is used for loudness of sound or noise |
| A. | Linear scale |
| B. | Logarithmic scale |
| C. | Exponential scale |
| D. | None of the above |
| Answer» B. Logarithmic scale | |
| 145. | Sound Intensity is given by. |
| A. | I=w/s |
| B. | I=s/w |
| C. | w=I/s |
| D. | s=w/I |
| Answer» A. I=w/s | |
| 146. | Unit for Reference sound intensity is_________. |
| A. | W/m2 |
| B. | W/mm3 |
| C. | W/cm3 |
| D. | None of the above |
| Answer» A. W/m2 | |
| 147. | Sound power of a machine whose specified sound power level is 125 dB |
| A. | 3.16 w |
| B. | 4.2w |
| C. | 5w |
| D. | 31.6w |
| Answer» A. 3.16 w | |
| 148. | The process of maintaining appropriate noise level without considering economic factors is called as _____ |
| A. | noise control |
| B. | noise reduction |
| C. | both a. and b. |
| D. | none of the above |
| Answer» B. noise reduction | |
| 149. | Basic elements of noise control are |
| A. | Source ,Path ,Receiver of noise |
| B. | Amplitude and Frequency |
| C. | Time period |
| D. | A and B both |
| Answer» A. Source ,Path ,Receiver of noise | |
| 151. | Main sources of noise pollution are |
| A. | Transportation equipment only |
| B. | Heavy machinery only |
| C. | Musical instruments |
| D. | Transportation equipment and heavy machinery |
| Answer» D. Transportation equipment and heavy machinery | |
| 152. | The sound can travel in air when: |
| A. | Particles of medium travel from one place to another |
| B. | There is no moisture in the atmosphere |
| C. | Disturbance travel from one place to another |
| D. | Both particles as well as disturbance travel from one place to another |
| Answer» C. Disturbance travel from one place to another | |
| 153. | White noise is random noise that has a audible frequency rangefrom |
| A. | 320 to 100 KHz |
| B. | 20 to 20KHtz |
| C. | 120 to 20KHtz |
| D. | 220 to 20KHtz |
| Answer» B. 20 to 20KHtz | |
| 154. | Which among the following has a constant power spectral density over a wide frequency range? |
| A. | White noise |
| B. | Black noise |
| C. | Pink noise |
| D. | Blue noise |
| Answer» A. White noise | |
| 155. | Which is correct option for ear protection equipment? |
| A. | Headphone |
| B. | Use of cotton in ears |
| C. | Ear defeders ,Ear plugs |
| D. | All the above |
| Answer» C. Ear defeders ,Ear plugs | |
| 156. | The technique or method to absorb undesirable sounds by soft and porous |
| A. | Acoustic protection |
| B. | Unacoustic protection |
| C. | Audible protection |
| D. | Decibel protection |
| Answer» A. Acoustic protection | |
| 157. | When sound interacts with materials and boundaries, it displays all the |
| A. | Heat |
| B. | Waves |
| C. | Light |
| D. | Electricity |
| Answer» B. Waves | |
| 158. | Soft materials absorb a large amount of |
| A. | Heat energy |
| B. | Light energy |
| C. | Electromagnetic waves |
| D. | Sound energy |
| Answer» D. Sound energy | |
| 159. | Reflection coefficient (Γ) is the rario of intensity of sound ______________. |
| A. | Reflected / Incident. |
| B. | Incident / Reflected. |
| C. | Absorbed / Reflected. |
| D. | None of the above. |
| Answer» A. Reflected / Incident. | |
| 160. | Absorption coefficient (α) is the rario of intensity of sound ______________. |
| A. | Absorbed / Incident. |
| B. | Incident / Reflected. |
| C. | Absorbed / Incident. |
| D. | None of the above. |
| Answer» C. Absorbed / Incident. | |
| 161. | Which best describe the sound wave? |
| A. | It may be longitudinal |
| B. | It is always transverse |
| C. | It is always longitudinal |
| D. | All of the above |
| Answer» C. It is always longitudinal | |
| 162. | Which of the following can not travel through a vacuum? |
| A. | Electromagnetic wave |
| B. | Radio wave |
| C. | Sound wave |
| D. | Light wave |
| Answer» C. Sound wave | |
| 163. | Through which medium does sound travel fastest? |
| A. | Air |
| B. | Steel |
| C. | Water |
| D. | Mercury |
| Answer» B. Steel | |
| 164. | Sound wave has two main characteristics which are |
| A. | Pitch and loudness |
| B. | Tone and loudness |
| C. | Highness and loudness |
| D. | Rarefaction and compression |
| Answer» A. Pitch and loudness | |
| 165. | When waves bend away from straight lines of travel, it is called |
| A. | Reflection |
| B. | Diffraction |
| C. | Rarefaction |
| D. | Refraction |
| Answer» D. Refraction | |
| 166. | _________ is the sound power measured over the area upon which is received. |
| A. | Sound pressure |
| B. | Sound energy |
| C. | Sound intensity |
| D. | Sound pressure level |
| Answer» C. Sound intensity | |
| 167. | It is an audio transducer that converts acoustic pressure in air into its equivalent electrical impulses |
| A. | Loudspeaker |
| B. | Amplifier |
| C. | Baffle |
| D. | Microphone |
| Answer» D. Microphone | |
| 168. | _________ is a pressure type microphone with permanent coil as a transducing element. |
| A. | Dynamic |
| B. | Condenser |
| C. | Magnetic |
| D. | Carbon |
| Answer» A. Dynamic | |
| 169. | A capacitor stores energy in the form of an electrostatic field is a ______. |
| A. | Dynamic Microphone |
| B. | Condenser Microphone |
| C. | Magnetic Microphone |
| D. | Carbon Microphone |
| Answer» B. Condenser Microphone | |
| 170. | A microphone that uses the piezoelectric effect |
| A. | Dynamic |
| B. | Condenser |
| C. | Crystal |
| D. | Carbon |
| Answer» C. Crystal | |
| 171. | It describes the output of a microphone over a range of frequencies. |
| A. | Directivity |
| B. | Sensitivity |
| C. | Frequency response |
| D. | All of the above |
| Answer» C. Frequency response | |
| 172. | The most important terms that are used to describe the sound field around a sound emitting object |
| A. | Far , Near Field |
| B. | Free ,Diffuse Field |
| C. | A and B both |
| D. | None of the above |
| Answer» C. A and B both | |
| 173. | The sound waves behave in a much more complex fashion, and there is no fixed relationship between ________________. |
| A. | Sound pressure |
| B. | pressure and distance |
| C. | Sound energy |
| D. | Sound intensity |
| Answer» B. pressure and distance | |
| 174. | The sound far field is beginning at a distance of ____________ . |
| A. | pressure and distance |
| B. | Sound energy |
| C. | Sound pressure |
| D. | 2 wavelengths away from the sound source |
| Answer» D. 2 wavelengths away from the sound source | |
| 175. | Measurement of noise can be made in following environment ____________ |
| A. | Anechoic Chamber |
| B. | Semi – anechoic Chamber |
| C. | Reverberant Chamber |
| D. | All the above |
| Answer» D. All the above | |
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