1. 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.
Correct : C. 200
2. 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.
Correct : D. 10
3. 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.
Correct : A. 0.26m
4. What is the function of frequency analyzer?
Correct : B. It analysis noise signal in frequency domain into various frequency bands by electronically separating the signal
5. What is the function of the controller in active vibration isolation systems?
Correct : C. Interpret detected vibrations and execute commands
6. Temperature monitoring technique uses which of the following devices to measure temperature of the machining surfaces?
Correct : D. All of the above
7. Which of the following statements is true about stroboscope?
Correct : A. Stroboscope is non-contact type frequency instrument
8. Which type of frequency measuring instrument has multiple reeds of different natural
frequency to measure vibrations?
Correct : B. Frahm Tachometer
9. Which of the following instruments measure amplitude of a vibrating body?
Correct : C. Both a. and b.
10. Which of the following vibrometers have frequency ratio (ω/ωn) << 1?
Correct : A. Accelerometers
11. Which type of monitoring system uses stroboscope to measure speed of the machine?
Correct : B. Basic condition monitoring system
12. Seismometer can be used to measure acceleration of any instrument only if _____
Correct : C. both a. and b.
13. In FFT Spectrum Analyzer, the D/A converter is used to ________.
Correct : D. converts digital signals into analog signals
14. In FFT Spectrum Analyzer, the A/D converter is used to ________.
Correct : C. convert analog signals into digital signals
15. In FFT Spectrum Analyzer, the attenuator is used to ________.
Correct : B. sets the level of the signals to be fed to the A/D converter
16. In FFT Spectrum Analyzer, the filter is used to ________.
Correct : A. reject unwanted signals
17. FFT analyzer can be used to find the ___________.
Correct : C. both natural frequencies and mode shapes
18. Fourier transform is a mathematical procedure to obtain the __________ of a given input
signal.
Correct : A. spectrum
19. In FFT Spectrum Analyzer, FFT stands for _______.
Correct : D. Fast Fourier Transform
20. From the following, which one is used in an accelerometer?
Correct : B. Piezoelectric crystals
21. The accelerometers are commonly used in vibration measurement due to their ___________.
Correct : D. small size and high sensitivity
22. Which instrument is used to record building vibrations or vibrations of huge structures like railway bridges?
Correct : C. Vibrometer
23. Vibration measuring instruments are classified on the basis of ____________.
Correct : D. all of the above
24. From the following, which one is also known as low-frequency Transducer?
Correct : C. Vibrometer
25. From the following, which one is a type of vibration measuring instrument?
Correct : D. All of the above
26. An accelerometer is an instrument used to measure the _________ of a vibrating body.
Correct : C. acceleration
27. Stroboscope is used for the measurement of _________________?
Correct : A. Rpm of a flywheel
28. A seismometer is a device used to measure the ___________ of a vibrating body.
Correct : A. displacement
29. The instruments which are used to measure the ___________ of a vibrating body are
called vibration measuring instrument.
Correct : D. all of the above
30. The accelerometer is used as a transducer to measure earthquake in Richter scale. Its
design is based on the principle that ______.
Correct : C. its natural frequency is equal to the frequency of vibration
31. Which of the following instruments measure the amplitude of a vibrating body?
Correct : C. Both (a) and (b)
32. Which of the following systems produce a vibration in the foundation?
Correct : D. Unbalanced machine
33. What does the accelerometer measure?
Correct : B. Acceleration
34. Which of the following device can be used for measurement of frequency?
Correct : C. Stroboscope
35. Which of the following is correct regarding isolation factor?
Correct : A. Dimensionless quantity
36. If the damper is not provided and the system is in resonance, which of the following is the correct
isolation factor?
Correct : D. Infinity
37. Which part of human ear converts sound vibrations into electrical signals
Correct : D. Cochlea
38. Sound is measured by units that are called
Correct : B. Decibels (dB)
39. 'Eardrum' bursts at
Correct : C. 160 dB
40. The loudness of sound varies directly with the vibrating body's
Correct : B. Amplitude
41. The scale to measure the intensity level of sound is called
Correct : D. decibel scale
42. Pitch of the sound depends upon
Correct : A. Frequency
43. Noise is
Correct : D. all of the above
44. Following scale is used for loudness of sound or noise
Correct : B. Logarithmic scale
45. Sound Intensity is given by.
Correct : A. I=w/s
46. Unit for Reference sound intensity is_________.
Correct : A. W/m2
47. Sound power of a machine whose specified sound power level is 125 dB
Correct : A. 3.16 w
48. The process of maintaining appropriate noise level without considering
economic factors is called as _____
Correct : B. noise reduction
49. Basic elements of noise control are
Correct : A. Source ,Path ,Receiver of noise
50. All sound is noise.
Correct : B. False
51. Main sources of noise pollution are
Correct : D. Transportation equipment and heavy machinery
52. The sound can travel in air when:
Correct : C. Disturbance travel from one place to another
53. White noise is random noise that has a audible frequency rangefrom
Correct : B. 20 to 20KHtz
54. Which among the following has a constant power spectral density over a wide
frequency range?
Correct : A. White noise
55. Which is correct option for ear protection equipment?
Correct : C. Ear defeders ,Ear plugs
56. The technique or method to absorb undesirable sounds by soft and porous
Correct : A. Acoustic protection
57. When sound interacts with materials and boundaries, it displays all the
Correct : B. Waves
58. Soft materials absorb a large amount of
Correct : D. Sound energy
59. Reflection coefficient (Γ) is the rario of intensity of sound ______________.
Correct : A. Reflected / Incident.
60. Absorption coefficient (α) is the rario of intensity of sound ______________.
Correct : C. Absorbed / Incident.
61. Which best describe the sound wave?
Correct : C. It is always longitudinal
62. Which of the following can not travel through a vacuum?
Correct : C. Sound wave
63. Through which medium does sound travel fastest?
Correct : B. Steel
64. Sound wave has two main characteristics which are
Correct : A. Pitch and loudness
65. When waves bend away from straight lines of travel, it is called
Correct : D. Refraction
66. _________ is the sound power measured over the area upon which is received.
Correct : C. Sound intensity
67. It is an audio transducer that converts acoustic pressure in air into its equivalent
electrical impulses
Correct : D. Microphone
68. _________ is a pressure type microphone with permanent coil as a transducing
element.
Correct : A. Dynamic
69. A capacitor stores energy in the form of an electrostatic field is a ______.
Correct : B. Condenser Microphone
70. A microphone that uses the piezoelectric effect
Correct : C. Crystal
71. It describes the output of a microphone over a range of frequencies.
Correct : C. Frequency response
72. The most important terms that are used to describe the sound field around a
sound emitting object
Correct : C. A and B both
73. The sound waves behave in a much more complex fashion, and there is no fixed
relationship between ________________.
Correct : B. pressure and distance
74. The sound far field is beginning at a distance of ____________ .
Correct : D. 2 wavelengths away from the sound source
75. Measurement of noise can be made in following environment ____________